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Magnetoreception in Honeybees

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Abstract

Magnetoreception by honeybees (Apis mellifera) is demonstrated by such activities as comb building and homing orientation, which are affected by the geomagnetic field. In other magnetoreceptive species, iron oxide crystals in the form of magnetite have been shown to be necessary for primary detection of magnetic fields. Here it is shown that trophocytes, which are apparently the only iron granule—containing cells in honeybees, contain super-paramagnetic magnetite. These cells are innervated by the nervous system, which suggests that trophocytes might be primarily responsible for magnetoreception. Electron microscopy also shows cytoskeletal attachments to the iron granule membrane.

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... Microscopic characterization techniques that can resolve the structure of tissues, cells or particles and/or their chemical/ mineral composition, form the basis of all direct observations in the field (table 2) [30,[41][42][43]45,[49][50][51][52][53][54][55][56][57][58][59][60][61][62]. The most widely used approach has been to combine light microscopy with the histological stain Perls' Prussian blue, which renders ferric iron (Fe 3þ ) blue in colour [51,52,62]. ...
... Two different anatomical sites have been proposed as possible locations for an MPM: (i) the anterior dorsal region of the abdomen, where evidence suggests SPM and SD magnetite particles are present rsif.royalsocietypublishing.org J. R. Soc. Interface 12: 20150499 [71,97] and (ii) iron granules located in sheets of trophocyte cells in the subcuticular fat layer of the ventral abdomen [54,85]. Using SQUID, transversely oriented SPM magnetite was indirectly detected in the anterior dorsal region of the abdomen [71,98] and direct TEM observations have revealed the presence of 15 -30 nm (SPM/SD) and 3-5 nm (SPM) magnetite in digested tissue extracts of newly hatched worker honeybees [99]. ...
... The potential role of these granules for magnetoreception has been debated. Ventrally located trophocyte cells were claimed to be innervated by axons connected to the ganglia that exist along the ventral nerve cord in the abdomen, and that the iron granules contained an SPM magnetite component [54]. These findings were later challenged, and the interpretation and validity of these results were questioned on a number of fronts [103]. ...
Article
Behavioural studies underpin the weight of experimental evidence for the existence of a magnetic sense in animals. In contrast, studies aimed at understanding the mechanistic basis of magnetoreception by determining the anatomical location, structure and function of sensory cells have been inconclusive. In this review, studies attempting to demonstrate the existence of a magnetoreceptor based on the principles of the magnetite hypothesis are examined. Specific attention is given to the range of techniques, and main animal model systems that have been used in the search for magnetite particulates. Anatomical location/cell rarity and composition are identified as two key obstacles that must be addressed in order to make progress in locating and characterizing a magnetite-based magnetoreceptor cell. Avenues for further study are suggested, including the need for novel experimental, correlative, multimodal and multidisciplinary approaches. The aim of this review is to inspire new efforts towards understanding the cellular basis of magnetoreception in animals, which will in turn inform a new era of behavioural research based on first principles. © 2015 The Author(s).
... Previous studies of magnetoreception in honey bees have addressed the location of the magnetoreceptor [44,[50][51][52][53], its formation [51,52] and potential mechanisms for encoding the direction and intensity of the (geo)magnetic field [31,50,52,54]. While some of these studies provide evidence for the presence of magnetite in honey bees (reviewed in [55]), no studies have directly linked magnetite to a magnetoreceptive function. ...
... Previous studies of magnetoreception in honey bees have addressed the location of the magnetoreceptor [44,[50][51][52][53], its formation [51,52] and potential mechanisms for encoding the direction and intensity of the (geo)magnetic field [31,50,52,54]. While some of these studies provide evidence for the presence of magnetite in honey bees (reviewed in [55]), no studies have directly linked magnetite to a magnetoreceptive function. ...
... Previous studies of magnetoreception in honey bees have addressed the location of the magnetoreceptor [44,[50][51][52][53], its formation [51,52] and potential mechanisms for encoding the direction and intensity of the (geo)magnetic field [31,50,52,54]. While some of these studies provide evidence for the presence of magnetite in honey bees (reviewed in [55]), no studies have directly linked magnetite to a magnetoreceptive function. ...
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Previous studies of magnetoreception in honey bees, Apis mellifera, focused on the identification of magnetic material, its formation, the location of the receptor and potential underlying sensory mechanisms, but never directly linked magnetic material to a magnetoreceptive function. In our study, we demonstrate that ferromagnetic material consistent with magnetite plays an integral role in the bees' magnetoreceptor. Subjecting lyophilized and pelletized bee tagmata to analyses by a superconducting quantum interference device generated a distinct hysteresis loop for the abdomen but not for the thorax or the head of bees, indicating the presence of ferromagnetic material in the bee abdomen. Magnetic remanence of abdomen pellets produced from bees that were, or were not, exposed to the 2.2-kOe field of a magnet while alive differed, indicating that magnet exposure altered the magnetization of this magnetite in live bees. In behavioural two-choice field experiments, bees briefly exposed to the same magnet, but not sham-treated control bees, failed to sense a custom-generated magnetic anomaly, indicating that magnet exposure had rendered the bees' magnetoreceptor dysfunctional. Our data support the conclusion that honey bees possess a magnetite-based magnetoreceptor located in the abdomen.
... cryptochrome involvement in honey bee magnetoreception so far, the cytochrome remains a candidate effector of magnetoreception in the honey bee. Previous studies have mainly focused on the location 14,21,45,46,48,49 , formation 46,48 , organization and possible magnetoreception mechanism 21,49 of the iron granules. These studies have all indicated that the iron granules have the potential to be magnetoreceptors, but they have not directly confirmed the association of the iron granules with magnetoreception in the honey bee [51][52][53] . ...
... This finding may be a result of the method used to collect the foragers. The suspected magnetoreceptor of the honey bees, the iron granules, accumulate as bees age [47][48][49] . We did not precisely control for the age of the tested bees but captured the individuals as they flew out of the hive. ...
... Once we confirmed that the bees could sense the magnetic field, we tried to identify the source of the signal. Previous studies have mainly focused on the location 14,21,45,46,48,49 , formation 46,48 , organization and the possible magnetoreception mechanism 21,49 of the iron granules. These studies all have indicated that the iron granules have the potential to be magnetoreceptors, but they have not directly confirmed the association of the iron granules with magnetoreception in the honey bee. ...
Article
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Honey bees have the ability to detect the Earth’s magnetic field, and the suspected magnetoreceptors are the iron granules in the abdomens of the bees. To identify the sensing route of honey bee magnetoreception, we conducted a classical conditioning experiment in which the responses of the proboscis extension reflex (PER) were monitored. Honey bees were successfully trained to associate the magnetic stimulus with a sucrose reward after two days of training. When the neural connection of the ventral nerve cord (VNC) between the abdomen and the thorax was cut, the honey bees no longer associated the magnetic stimulus with the sucrose reward but still responded to an olfactory PER task. The neural responses elicited in response to the change of magnetic field were also recorded at the VNC. Our results suggest that the honey bee is a new model animal for the investigation of magnetite-based magnetoreception.
... More recently, it was demonstrated that honeybees can be trained to elicit a proboscis extension reflex in response to magnetic field exposure, which is interrupted when the ventral nerve cord between the thorax and abdomen is severed [26]. A magnetoreceptor based on superparamagnetic magnetite was proposed to be present in hairs on the anterior dorsal region of the abdomen [27] but other studies have postulated the abdominal fat body as a target site because of the presence of iron granules [22,28,29]; but see [30]. In summary, the location and function of a magnetic receptor remains unresolved in honeybees, despite a substantial amount of work conducted on their magnetic sense. ...
... The fat body is present in both the tergites and stergites, and hence the fat body in the stergite segments is proportionally smaller than that of the tergites. In addition to claims of an iron-based magnetoreceptor located within the anterior dorsal region of the abdomen [17,21,26], the ventral fat body has also been marked as a potential area of interest [22,28]. However, the iron in the trophocyte cell granules is reported to be the relatively disordered and weakly magnetic form of iron oxide ferrihydrite, as found in the iron storage protein ferritin [23], which is not considered to possess sufficient magnetism to act as a torque-based magnetic particle receptor system (i.e. the magnetite hypothesis) [1,38]. ...
Article
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The honeybee Apis mellifera is one of many animal species for which empirical evidence of a magnetic sense has been provided. The underlying mechanisms postulated for magnetoreception in bees are varied, but most point towards the abdomen as the most likely anatomical region for its location, partly owing to the large accumulation of iron in trophocyte cells that comprise the honeybee fat body. Using a multi-modal imaging and analysis approach, we have investigated iron in the honeybee, with a particular focus on the abdomen and the utility of such techniques as applied to magnetoreception. Abdominal iron is shown to accumulate rapidly, reaching near maximum levels only 5 days after emerging from the comb and is associated with the accumulation of iron within the fat body. While fat body iron could be visualized, no regions of interest, other than perhaps the fat body itself, were identified as potential sites for magnetoreceptive cells. If an iron-based magnetoreceptor exists within the honeybee abdomen the large accumulation of iron in the fat body is likely to impede its discovery.
... The honeybee species exhibit excellent orientation in their habitats and one of the cues for this property could be a magnetoreception based on presence of iron-containing particles in their body. Since the iron-based magnetoreception was already studied in detail on bodies of honeybees, it could be possible to expect a very similar occurrence and significance of iron-based particles in the bodies of bumblebees (Hsu and Chan 2011;Hsu et al. 2007;Hsu and Li 1994). ...
... The ferromagnetic material was also detected using a magnetic resonance method (El-Jaick et al. 2001). Hsu and Li (1994) discovered that the abdomen cells contain trophocytes rich in clusters of superparamagnetic particles connected with their cell membrane, thus reaching a hypothesis of the magnetosensoric function of superparamagnetic trophocytes (Hsu et al. 2007). Subsequently they found that the alternative external magnetic field induces size fluctuations of superparamagnetic clusters. ...
Article
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The paper deals with the presence of iron-based granules in body parts of bumblebees. Two groups of bumblebees were collected from their natural habitat, industrial landscape, and from a breeding station. Detection of the magnetic particles was performed by a vibratory magnetometer and their morphology and elemental composition was analysed by scanning electron microscopy with EDX micro-analysis. By means of the EDX spectra, wild bumblebees were found to have many magnetic and nonmagnetic particles on their body, containing Fe, O, Al, Si, Bi, Mg, K, and Ni, likely having origin in the industrial pollution of the environment. In the case of bred bumblebees the presence of iron-rich granules, which occurred more abundantly in subsurface tissues on the head and wings, was observed. Phase analysis based on X-ray diffraction shows that iron-based granules contain magnetite and wuestite and Mossbauer spectroscopy admits a superparamagnetic form of these minerals. Magnetoreception, i.e. the sensory function of these granules, is discussed within the paper.
... Earth's dipole magnetic field has been reported to influence the behavior and orientation of numerous types of organisms (Guyton 1971). These include magnetotactic bacteria, algae, marine mollusks, honeybees, hornets, salmon, tuna, salamanders, turtles, pigeons, cetaceans and, indeed, humans (see, for example, Able and Able 1993;Baker 1980;Hsu and Li 1994;Lohmann and Willows 1987;Wiltschko et al. 1993). Such effects presumably lack clinical significance. ...
... Indeed, laboratory and epidemiological investigations to elucidate possible associations of EMFs with a variety of health effects have become extensive. For example, reports of such investigations have addressed possible field strength associations with immunological effects (Lyle et al. 1983), neurological effects (Adey, Bawin, and Lawrence 1982;Bawin, Kaczmarek, and Adey 1975;Blackman et al. 1980;Dutta et al. 1984;Graham et al. 2000;Lai, Horita, and Guy 1994), adverse reproductive outcomes (Meyer, Aldrich, and Easterly 1989;Shaw and Croen 1993), adverse developmental effects (Berman et al. 1990;Hsu and Li 1994;Nelson et al. 1994;Nelson, Snyder, and Shaw 2001), cancer (Chen et al. 2000;Coleman et al. 1989;Dolk et al. 1997a, b;Feychting and Ahlbom 1993;Fulton et al. 1980;Goldsmith 1997;Hocking et al. 1996;Kaune et al. 1987;London et al. 1991;Myers et al. 1990;Repacholi 1997;Repacholi et al. 1997;Salford et al. 1993;Savitz et al. 1988;Severson et al. 1988;Tomenius 1986;Wertheimer and Leeper 1979, 1982Youngston et al. 1991), and cancer promotion (Adey 1990;Anderson 2000;Balcer-Kubiczek and Harrison 1991;Beniashvili, Bilanishvili, and Menabde 1991;Cleary, Liu, and Merchant 1990;L€ oscher et al. 1993;McLean 1993;Mevissen et al. 1993;Stuchly et al. 1992). ...
Article
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Telecommunication generates electromagnetic fields (EMFs) at radio and microwave frequencies. Transmitters have proliferated with siting of wireless communication networks, often co-located among other transmitters. ‘Cell’ phones also have proliferated, representing small transmitters used in contact with human heads, and stored on human bodies. Telecommunications equipment is ubiquitous, and EMF exposure prolonged, raising the issue of possible health risks. Such risks, if any, must be managed. For example, epidemiology studies reported higher exposure to analog cell phone EMFs among brain cancer patients than among controls, but those risks were ‘managed’ via replacement of analog phones with today’s digital phones, which have not been associated with human cancer. Challenges remain, recently from rodent bioassays that show dose-related association of lifetime exposure to cell-phone-type EMFs with heart schwannomas (cancers of schwann cells, which insulate nerve cells) in male rats, though not females. Human cancer risk, if any, remains to be characterized and quantified, which partly will depend upon whether EMFs indeed are non-ionizing as has been assumed, and whether a threshold or non-threshold (genotoxic) mechanism caused the cancers in the male rats. Health concerns have motivated further exposure reduction suggestions, and sometimes opposition to siting transmitters. Credible, objective explication of technical information to primarily non-technical audiences is necessary to support informed public participation and dispassionate weighing of telecommunications risks and benefits in community decision-making. Ultimately, experts and non-experts should adhere to the ‘precautionary principle’, requiring adoption of reasonably (but not excessively) pessimistic exposure and risk assumptions, whether or not they are likely to materialize.
... (1993) found in the abdominal hairs of these bees, particles of magnetite that might be involved in the detection and amplification of the external magnetic field gradients. Other studies have also indicated the presence of iron oxides by biomineralization (Gould et al. 1978;kuterbaCh & WalCott 1986;hsu & li 1994). ...
... Thus the deposition of intracellular iron was first demonstrated in cells of honeybees (kuterbaCh et al. 1986;hsu & li 1994), then in bumblebees (WalCott 1985) and later in wasps by hsu (2004). ...
Article
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Magnetoreception is a mechanism of active orientation that occurs in animals with nervous systems. Social insects such as bees, ants, wasps and termites have been studied on the influence of the magnetic field exerts on its biology. The social wasps comprise species represented in Stenogastrinae, Vespinae and Polistinae, however studies on the influence of magnetic field on wasps Vespinae address only. The areas studied include the biomineralization of magnetic material and behavioral aspects related to changes in local intensity of the geomagnetic field. The objective of this review is to integrate knowledge of social wasps' magnetoreception in order to build an instructive overview of the current situation of studies, therefore, provide the conceptual framework for the development of future work on the topic. Magnetorrecepção em Vespas Sociais: Uma Atualização Resumo. Magnetorrecepção é um mecanismo de orientação ativa que ocorre em animais com sistema nervoso. Insetos sociais tais como abelhas, formigas, vespas e cupins são estudados sobre a influência que o campo magnético exerce em sua biologia. As vespas sociais compreendem espécies representadas em Stenogastrinae, Vespinae e Polistinae, no entanto os estudos sobre a influência do campo magnético em vespas abordam somente Vespinae. As áreas de estudo incluem a biomineralização do material magnético e aspectos comportamentais relacionados a mudanças na intensidade do campo geomagnético local. O objetivo desta revisão é integrar o conhecimento sobre magnetorrecepção em vespas sociais, a fim de construir um panorama elucidativo da atual situação dos estudos, e assim fornecer uma estrutura conceitual para o desenvolvimento de trabalhos futuros sobre o tema.
... Aside from ALAN, the IPBES report (IPBES, 2016;Potts et al., 2016) did not consider other sources and wavelengths of anthropogenic EMR. This was because it was judged at that time (publications up to July 2015) there was insufficient data for an evidence assessment, with only a few studies showing how bees utilise magnetic fields (Clarke et al., 2013;Gould et al., 1978;Hsu and Li, 1994) and fewer still on potential effects of AREMR (Favre, 2011;Greenberg et al., 1981). Similarly, AREMR (and ALAN) were not identified as a risk in a 2016 horizon scan of future threats and opportunities for pollinators and pollination (Brown et al., 2016). ...
... Therefore, the perception remains that AREMR (in addition to ALAN) poses a current and growing risk to pollinators and pollination (Balmori, 2015). Studies have shown the honey bee (Apis mellifera) is able to detect magnetic fields physiologically (Gould et al., 1978;Hsu and Li, 1994;Kirschvink and Kirschvink, 1991;Lambinet et al., 2017;Liang et al., 2016) and potentially use this capacity for orientation, navigation and foraging (Fig. 2). Furthermore, bees use electric fields of the same magnitude as commonly encountered AREMR for intraspecific (within hive) and interspecific (plant-pollinator) communication, in the context of foraging on floral resources (Clarke et al., 2013;Greggers et al., 2013). ...
Article
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Worldwide urbanisation and use of mobile and wireless technologies (5G, Internet of Things) is leading to the proliferation of anthropogenic electromagnetic radiation (EMR) and campaigning voices continue to call for the risk to human health and wildlife to be recognised. Pollinators provide many benefits to nature and humankind, but face multiple anthropogenic threats. Here, we assess whether artificial light at night (ALAN) and anthropogenic radiofrequency electromagnetic radiation (AREMR), such as used in wireless technologies (4G, 5G) or emitted from power lines, represent an additional and growing threat to pollinators. A lack of high quality scientific studies means that knowledge of the risk to pollinators from anthropogenic EMR is either inconclusive, unresolved, or only partly established. A handful of studies provide evidence that ALAN can alter pollinator communities, pollination and fruit set. Laboratory experiments provide some, albeit variable, evidence that the honey bee Apis mellifera and other invertebrates can detect EMR, potentially using it for orientation or navigation, but they do not provide evidence that AREMR affects insect behaviour in ecosystems. Scientifically robust evidence of AREMR impacts on abundance or diversity of pollinators (or other invertebrates) are limited to a single study reporting positive and negative effects depending on the pollinator group and geographical location. Therefore, whether anthropogenic EMR (ALAN or AREMR) poses a significant threat to insect pollinators and the benefits they provide to ecosystems and humanity remains to be established.
... In fact magnetic particles have been claimed to be found in many animals (e.g. honeybees [494] ). However in many cases it turned out that the magnetic particles were just contaminations from the environment which were accumulated during the preparation of the specimen. ...
... Ayrıca bal arılarının yağ dokusu hücrelerinde manyetik kristallerin bulunduğu ve bu durumunda manyetik çekime neden olduğu belirtilmektedir (Gould et al., 1978; Keim et al. 2002). Bu manyetik yapıların; yön, yükseklik ve lokasyon bulmada rol oynayan manyetik reseptör sisteminin aktif bölgesi olduğu vurgulanmaktadır (Hsu ve Li, 1994; Hsu et al., 2007). Bal arılarının bölgesel jeomanyetik alanlardaki küçük değişimlere karşı eğitilebileceği belirtilmektedir (Walker ve Bitterman, 1989). ...
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Özet Bal arıları sadece bal ve bal ürünlerini (propolis, pollen, arı sütü ve bal mumu) ürettikleri için değil, aynı zamanda dünyada tarımsal üretimin gerçekleşmesi için gerekli olan en etkili tozlaştırıcılardan biridir. Bu sebeplerden dolayı, bal arıları tarımsal ekonomi ve üretimde temel role sahiptir. Çeşitli çalışmalardan elde edilen veriler değerlendirildiğinde birçok ülkede sebebi açıklanamayan arı koloni kayıpları vurgulanmış ve bunun gelecekteki etkileri hakkında endişe duyulmaya başlanmıştır. Bal arılarının aniden yok olması, kovan önünde ölü arıların bulunması, az sayıda ergin arı bulunması, bal üretiminde azalma, ürünlerin tozlaşmasında azalma 'Koloni Kaybı Sendromu' olarak adlandırılan durumun belirtileridir. Koloni kaybına pestisitler, gutasyon sıvısı, patojenler, zararlılar, küresel ısınma, cep telefonu radyasyonu ve stres gibi birçok faktör neden olmaktadır. Bu çalışmada bal arıları kayıplarının nedenleri ve bu nedenlere ışık tutacak potansiyel çözümler üzerinde durulmuştur. Anahtar Kelimeler: Bal arısı, koloni kaybı sendromu Honey Bee Colony Losses Abstract Honey bees not only produce the honey and hive products (propolis, pollen, royal jelly and wax) but also they are one of the most effective pollinators that are required for the realization of agricultural production in the world. In this manner, they have a fundamental role in global agricultural economy and production. The recent reports from various studies emphasized the unexplained losses of bee colonies in many countries and many governments have started to concern future effects of this occasion. Sudden disappearance of worker bees, dead bees in front of the hive, low number of adult bees, less produced honey and low pollinated crops are the symptoms which is described as colony collapse disorder (CCD). Colony losses seem to be driven by many factors such as pesticides, guttation water, pathogens, pests, global warming, cell phone radiation and stress factors. This review focuses on the reasons of honey bee decline and the potential solutions to shed light to honey bee disappearence.
... Magnetoreception, the ability to perceive the earth's magnetic field, is a sensory modality observed in various vertebrate species (Begall et al., 2014), some invertebrates taxa (Hsu and Li, 1994;Lee et al., 2021) and even in plants (Galland and Pazur, 2005). Unlike surface-dwelling rodents, subterranean rodents lack some external stimuli that are normally used for spatial orientation, such as stars, sun light azimuth, and other visual cues. ...
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On the social scale, the blind mole rat (BMR; Spalax ehrenbergi) is an extreme. It is exceedingly solitary, territorial, and aggressive. BMRs reside underground, in self-excavated tunnels that they rarely leave. They possess specialized sensory systems for social communication and navigation, which allow them to cope with the harsh environmental conditions underground. This review aims to present the blind mole rat as an ideal, novel neuroethological model for studying aggressive and solitary behaviors. We discuss the BMR's unique behavioral phenotype, particularly in the context of 'anti-social' behaviors, and review the available literature regarding its specialized sensory adaptations to the social and physical habitat. To date, the neurobiology of the blind mole rat remains mostly unknown and holds a promising avenue for scientific discovery. Unraveling the neural basis of the BMR's behavior, in comparison to that of social rodents, can shed important light on the underlying mechanisms of psychiatric disorders in humans, in which similar behaviors are displayed.
... Afhankelijk van de plek op aarde, varieert de sterkte van het aardmagnetisch van minder dan 30 µT (microTesla) tot meer dan 60 µT. Bijen kunnen het aardmagnetisch veld waarnemen (Gould et al. 1978, Keim et al. 2002, Hsu & Li 1994 Hsu et al. 2007), en gebruiken dit onder meer om de richting te bepalen waarin ze in donkere nestholten nieuwe raten bouwen. De receptor voor het aardmagnetisch veld is bij bijen erg gevoelig: hij kan velden detecteren van slechts 26 nT (nanoTesla, ofwel 0,026 µT). ...
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Veel volken van de honingbij overleven tegenwoordig de winter niet. Allerlei mogelijke oorzaken passeren de revue, waaronder de straling van het mobiele telefonie netwerk. Daar is weinig onder- zoek aan gedaan, maar het is bekend dat bijen magnetische en elektromagnetische velden kunnen detecteren en er op kunnen reageren. Het kan dus niet op voorhand worden uitgesloten dat bijen erdoor beïnvloed worden. Doelstelling van het onderzoek is om een relatie te kunnen leggen tussen aan de ene kant de dosis EMV die bijen in hun larvale en pupale stadium ondergaan en aan de andere kant hun ont- wikkeling en enkele kenmerken in hun volwassen leven (levensduur, vliegprestaties en morfolo- gische en fysiologische kenmerken). Ook wordt de ontwikkeling van het bijenvolk door het jaar heen (die een resultante is van de larvale, de pupale en de volwassen ontwikkeling) gemonitord.
... Based on current understanding, (marine) animals in the "electromagnetic induction" group and (terrestrial) animals in the "particle-based" group sense the polarity of the geomagnetic field, whereas animals in the "biochemical reaction" group do not (Ritz et al. 2000;Davila et al. 2003;Winklhofer and Kirschvink 2010). Because honey bees possess ferromagnetic particles (magnetite) in their abdomen (Gould et al. 1978;Hsu and Li 1994;Desoil et al. 2005) that are integral to their magnetoreceptor (Lambinet et al. 2017), we hypothesized that honey bees belong to the "particlebased" group and thus sense the polarity of a magnetic field. ...
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Honey bees, Apis mellifera, exploit the geomagnetic field for orientation during foraging and for alignment of their combs within hives. We tested the hypothesis that honey bees sense the polarity of magnetic fields. We created an engineered magnetic anomaly in which the magnetic field generally either converged toward a sugar reward in a watch glass, or away from it. After bees in behavioral field studies had learned to associate this anomaly with a sugar water reward, we subjected them to two experiments performed in random order. In both experiments, we presented bees with two identical sugar water rewards, one of which was randomly marked by a magnetic field anomaly. During the control experiment, the polarity of the magnetic field anomaly was maintained the same as it was during the training session. During the treatment experiment, it was reversed. We predicted that bees would not respond to the altered anomaly if they were sensitive to the polarity of the magnetic field. Our findings that bees continued to respond to the magnetic anomaly when its polarity was in its unaltered state, but did not respond to it when its polarity was reversed, support the hypothesis that honey bees possess a polarity-sensitive magnetoreceptor.
... Drones are accepted in any hive when the conditions are favorable, but they may be rejected by the workers for different reasons, including the lack of food in the hive and the advanced age of drones. Because spatial orientation is critical for the survival and reproduction of honey bees, evident behavioral (Sullivan et al. 2003) and anatomical adaptations are observed in these insects, such as magnetic sensitivity and magnetite nanoparticles in the bee brain, thorax, and abdomen (Hsu and Li 1994, Frier et al. 1996, Hsu et al. 2007, and neurological adaptations (Fahrbach et al. 1998). ...
Article
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Honey bees [Apis mellifera L. (Apidae, Hymenoptera)] show spatial learning behavior or orientation, in which animals make use of structured home ranges for their daily activities. Worker (female) orientation has been studied more extensively than drone (male) orientation. Given the extensive and large flight range of drones as part of their reproductive biology, the study of drone orientation may provide new insight on landscape features important for orientation. We report the return rate and orientation of drones released at three distances (1, 2, and 4 km) and at the four cardinal points from an apiary located in Gurabo, Puerto Rico. We used high-resolution aerial photographs to describe landscape characteristics at the releasing sites and at the apiary. Analyses of variance were used to test significance among returning times from different distances and directions. A principal components analysis was used to describe the landscape at the releasing sites and generalized linear models were used to identify landscape characteristics that influenced the returning times of drones. Our results showed for the first time that drones are able to return from as far as 4 km from the colony. Distance to drone congregation area, orientation, and tree lines were the most important landscape characteristics influencing drone return rate. We discuss the role of landscape in drone orientation. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
... Honeybees possess magnetite crystals in their fat body cells and they present magnetic remanence (Gould et al., 1978;Keim et al., 2002). These magnetite structures are active parts of the magneto-reception system in honeybees (Hsu and Li, 1994;Hsu et al., 2007). Honeybees can be trained to respond to very small changes in the constant local geomagnetic field intensity (Walker and Bitterman, 1989a). ...
... Honeybees possess magnetite crystals in their fat body cells and they present magnetic remanence (Gould et al., 1978;Keim et al., 2002). These magnetite structures are active parts of the magneto-reception system in honeybees (Hsu and Li, 1994;Hsu et al., 2007). Honeybees can be trained to respond to very small changes in the constant local geomagnetic field intensity (Walker and Bitterman, 1989a). ...
... Studies of the apparent magnetoreceptivity of bees revealed their sensitivity to changes in the magnetic field [9], their sensitivity to the direction of the magnetic field [10], and their insensitivity to alternating magnetic fields [11]. Nevertheless, the nature of the receptor that is involved, the manner in which it functions, and its location are unknown or controversial [12][13][14][15][16][17][18]. ...
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The honeybee (Apis mellifera) waggle dance, which is performed inside the hive by forager bees, informs hive mates about a potent food source, and recruits them to its location. It consists of a repeated figure-8 pattern: two oppositely directed turns interspersed by a short straight segment, the "waggle run". The waggle run consists of a single stride emphasized by lateral waggling motions of the abdomen. Directional information pointing to a food source relative to the sun's azimuth is encoded in the angle between the waggle run line and a reference line, which is generally thought to be established by gravity. Yet, there is tantalizing evidence that the local (ambient) geomagnetic field (LGMF) could play a role. We tested the effect of the LGMF on the recruitment success of forager bees by placing observation hives inside large Helmholtz coils, and then either reducing the LGMF to 2% or shifting its apparent declination. Neither of these treatments reduced the number of nest mates that waggle dancing forager bees recruited to a feeding station located 200 m north of the hive. These results indicate that the LGMF does not act as the reference for the alignment of waggle-dancing bees.
... agnetic nanoparticles (MNPs) have been found in many organisms, such as magnetotactic bacteria [1] , pigeons [2] , honeybees [3] , and trout [4] . It was reported that MNPs may be associated with the navigation and orientation of organisms [5] . ...
Article
To investigate the bioeffects of extremely low frequency (ELF) magnetic field (MF) (50 Hz, 400 μT) and magnetic nanoparticles (MNPs) via cytotoxicity and apoptosis assays on PC12 cells. MNPs modified by SiO2 (MNP-SiO2) were characterized by transmission electron microscopy (TEM), dynamic light scattering and hysteresis loop measurement. PC12 cells were administrated with MNP-SiO2 with or without MF exposure for 48 h. Cytotoxicity and apoptosis were evaluated with MTT assay and annexin V-FITC/PI staining, respectively. The morphology and uptake of MNP-SiO2 were determined by TEM. MF simulation was performed by Ansoft Maxwell based on the finite element method. MNP-SiO2 were identified as ~20 nm (diameter) ferromagnetic particles. MNP-SiO2 reduced cell viability in a dose-dependent manner. MF also reduced cell viability with increasing concentrations of MNP-SiO2. MNP-SiO2 alone did not cause apoptosis in PC12 cells; instead, the proportion of apoptotic cells increased significantly under MF exposure and increasing doses of MNP-SiO2. MNP-SiO2 could be ingested and then cause a slight change in cell morphology. Combined exposure of MF and MNP-SiO2 resulted in remarkable cytotoxicity and increased apoptosis in PC12 cells. The results suggested that MF exposure could strengthen the MF of MNPs, which may enhance the bioeffects of ELF MF.
... • Another mechanism for magnetoception is magnetite. Iron oxide crystals in the form of magnetite are common; in honey bees cells containing super-paramagnetic magnetite perhaps explained their sensitivity to the full moon phase [138,139], and magnetotactic bacteria responded to geomagnetic fields. Magnetoception via biogenic magnetite, the only ferrimagnetic material in the human body [140], was established both for bats and humans [141,142], and there are trace levels of biogenic magnetite in most human tissues. ...
Article
The debate about how far the Moon causes biological effects has continued for two millennia. Pliny the Elder argued for lunar power "penetrating all things", including plants, fish, animals and humans. He also linked the Moon with tides, confirmed mathematically by Newton. A review of modern studies of biological effects, especially from plants and animals, confirms the pervasive nature of this lunar force. However calculations from physics and other arguments refute the supposed mechanisms of gravity and light. Recent space exploration allows a new approach with evidence of electromagnetic fields associated with the Earth's magnetotail at full moon during the night, and similar, but more limited, effects from the Moon's wake on the magnetosphere at new moon during the day. The disturbance of the magnetotail is perhaps shown by measurements of electric fields of up to 16V/m compared with the usual <1V/m, suggesting the possibility of weak biological effects on some sensitive organisms. Similar intensities found in sferics, geomagnetic storms, aurora disturbance, sensations of a 'presence' and pre-seismic electromagnetic radiation are known to affect animals and 10-20% of the human population. There is now evidence for mechanisms such as calcium flux, melatonin disruption, magnetite and cryptochromes. Both environmental and receptor variations explain confounding factors and inconsistencies in the evidence. Electromagnetic effects might also account for some evolutionary changes. Further research on lunar biological effects, such as acute myocardial infarction, could help the development of strategies to reduce adverse effects for people sensitive to geomagnetic disturbance.
... The size distribution of the nanoparticles collected from the different parts is between 5-50 nm. All previous works describe iron nanoparticles on the A. mellifera body (Could et al., 1980;Schiff, 1991), as well as on trophocytes (Hsu & Li, 1994;Hsu et al., 2007;El-Jaick et al., 2001). In our study, we clearly defined that the particles on the body of the A. dorsata bee were not iron but most probably calcium silicate and calcium phosphate in nature. ...
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The presence of nanoparticles on the body of the honeybee Apis dorsata Fabricius, was investigated for the first time to better understand the bee’s behaviour. These have been observed by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and confirmed by Atomic Force Microscopy (AFM). Our study clearly denotes that the Indian rock honey bee Apis dorsata possess calcium silicate and calcium phosphate nanoparticles on its body surface of 5-50 nm in diameter. In particular, the nanoparticles on the abdomen and thorax of A. dorsata have an average diameter of about 10 nanometers and they are smaller than those found on wings of the same bees which are about 20 nanometers. The nanoparticles found are different of the ones previously observed on honey bees or other insects. The origin and role of these natural nanoparticles on the body of the Indian rock bee need to be to be further investigated; more research in the subject might raise important aspects in relation to the conservation of these unique pollinators.
... Magnetic particles have been reported in the body parts of social insects mainly using magnetic techniques, such as ferromagnetic resonance (FMR) and superconducting quantum interference device (SQUID) magnetometry . In particular, the presence of magnetic particles in the abdomen of honeybees (Apis mellifera) (Gould et al. 1978;Kuterbach and Walcott 1986;Hsu and Li 1994), has led to controversial conclusions on their composition, magnetite or ferritin. Hsu and collaborators established a size-density purification procedure to recover adequate amounts of iron granules (IGs) from trophocytes for characterization and to demonstrate the presence of magnetite in these IGs and a model for magnetite biomineralization (Hsu et al. 2007;Hsu and Chan 2011). ...
Article
Ferritin has been studied in many animals, plants and bacteria. The main functions of ferritin in mammals are iron concentration and stabilization, protection against oxidants and iron storage for later developmental or iron-dependent activities. Although insect ferritin plays a key role in iron transport, only a few studies to date have examined its properties and function. Ferritin isolation from the haemolymph of adult Camponotus sericeiventris ants involved heating at 75 °C, followed by protein fractionation with 3.2 M KBr gradients and ferritin sedimentation with KBr. Protein identification was performed using high-resolution proteomics techniques. SDS-PAGE revealed three subunits with molecular weights (MW) of 26, 28 and 31 kDa. Native PAGE indicated a MW higher than 669 kDa. Proteomic analysis strongly suggested the 26 and 31 kDa bands as F2LCH and F1HCH subunits of ferritin, respectively. Ferromagnetic resonance (FMR) at 100 K showed, at low field, a characteristic broad component of the ferritin iron core, suggesting that its distribution was shifted to values greater than 3000, a higher content than in mammals. The protein yield and MW were comparable to those reported in other studies of insects. To the best of our knowledge, this is the first report on ferritin extracted from adult ants to date. These results are discussed on the basis of the protein structure–function relation of secreted insect and mammal ferritins. This purification method will allow the use of magnetic techniques, which are relevant for understanding the role of ferritin in the biomineralization of magnetic nanoparticles in insects.
... The artificial light altered the architecture of communities of nocturnal pollinator and reduced the visitation rates to plants by 62% leading to a 13% drop in the fruit set of a focal plant species (Cirsium oleraceum, Asteraceae) (Knop et al., 2017). Some studies have reported the effects of artificial street lighting on the reduction of local species richness, abundance, rates of pollen transport and feeding in moths (Macgregor, et al Gould et al., 1978;Hsu and Li, 1994) and few workers recognized the potential effects of AREMR (Greenberg et al., 1981;Favre, 2011). Another study related to biodiversity conservation, natural capital and ecosystem services, reported the potential, but unstudied threats of wildlife in form of non-ionizing radiation from wireless transmission setups and 5G mobile phones (Sutherland et al., 2018). ...
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Pollinators play a key functional role in most terrestrial ecosystems and provide important ecosystem service to maintain wild plant communities and agricultural productivity. The decline in pollinators has been related to anthropogenic disturbances such as habitat loss, alterations in land use, and climate change. The surge in mobile telephony has led to a marked increase in electromagnetic fields in the atmosphere, which may affect pollinator and pollination. Several laboratory studies have reported negative effects of electromagnetic radiation on reproduction, development, and navigation in insects. The abundance of insects such as the beetle, wasp, and hoverfly, decreased with electromagnetic radiation(EMR), whereas the abundance of underground-nesting wild bees and bee fly unexpectedly increased with EMR. Potential risks for pollinators and biodiversity are anthropogenic radiofrequency electromagnetic radiation (AREMR) (light, radiofrequency). Artificial light at night (ALAN) can alter the function and abundance of pollinator. Evidence of impacts of AREMR is not adequate due to a lack of high quality, field-realistic studies. Whether pollinators experiencing a threat of ALAN or AREMR, while major knowledge gap exists. In this review, the effects of EMR on wild pollinator groups such as wild bees, hoverflies, bee flies, beetles, butterflies, and wasps etc. have been highlighted. Researchers are also recommended for further study on the effects of EMR on insects. This study will be significant to conserve pollinators and other important insects.
... Because a moving charge creates a magnetic field, and in the reference frame of a bee approaching a flower, the flower is a moving charge, there will be some magnetic field associated with the bee-flower interaction. Bees have previously been shown to be capable of detecting magnetic fields (Hsu & Li, 1994;Wajnberg et al., 2010), and so it is possible that they are using this magnetoreceptive system to detect floral electric fields indirectly. However, it is unlikely that magnetoreceptive systems are capable of instantaneously acquiring magnetic information, instead relying upon longer scale time-averaged sampling methods (Johnsen, Lohmann & Warrant, 2020), and therefore the time course of the bee-flower interaction is probably too short to be detectable by magnetic means. ...
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Electricity, the interaction between electrically charged objects, is widely known to be fundamental to the functioning of living systems. However, this appreciation has largely been restricted to the scale of atoms, molecules, and cells. By contrast , the role of electricity at the ecological scale has historically been largely neglected, characterised by punctuated islands of research infrequently connected to one another. Recently, however, an understanding of the ubiquity of electrical forces within the natural environment has begun to grow, along with a realisation of the multitude of ecological interactions that these forces may influence. Herein, we provide the first comprehensive collation and synthesis of research in this emerging field of electric ecology. This includes assessments of the role electricity plays in the natural ecology of predator-prey interactions, pollination, and animal dispersal, among many others, as well as the impact of anthropogenic activity on these systems. A detailed introduction to the ecology and physiology of electroreception-the biological detection of ecologically relevant electric fields-is also provided. Further to this, we suggest avenues for future research that show particular promise, most notably those investigating the recently discovered sense of aerial electroreception.
... The discovery of superparamagnetic magnetite in the iron granules (IGs) of iron deposition vesicles (IDVs) of trophocytes supports the behavioral evidence of magnetoreception in honey bees [9,10]. A magnetic field causes the conformation changes of IGs resulting in the fluctuation of cytoskeletons on IDVs, which are used to establish a magnetic map during orientation flights [10]. ...
Article
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Behavioral studies indicate that honey bees ( Apis mellifera ) have a capacity for magnetoreception and superparamagnetic magnetite is suggested to be a magnetoreceptor. The long-term inhibition of magnetite formation can be employed to explore the bee’s magnetoreception. A recent study shows that magnetite formation, ferritin2 messenger RNA (mRNA) expression, and the protein synthesis of ferritin2 in trophocytes and oenocytes were all inhibited by a single injection of ferritin2 double-stranded RNA (dsRNA) into the hemolymph of honey bees but how to maintain this knockdown of ferritin2 for the long-term is unknown. In this study, we injected ferritin2 dsRNA into the hemolymph of worker bees three times every six days to maintain long-term inhibition; however, multi-microinjections accelerated the death of the bees. To overcome this problem, we further reared newly emerged worker bees daily with ferritin2 dsRNA throughout their lives, demonstrating no impact on their lifespans. Follow-up assays showed that the mRNA expression and protein synthesis of ferritin2 were persistently inhibited. These findings verified that daily ferritin2 dsRNA ingestion not only displays the long-term inhibition of mRNA expression and protein synthesis of ferritin2 , but also did not damage the bees. This method of long-term inhibition can be used in behavioral studies of magnetoreception in honey bees.
... 1986年, Phillips [20] 在 Science上报道了一种迁徙蝾螈(Notophthalms viridesens)的两 种感磁机制: 一种是类似于鸟类极性罗盘的轴向指南针; 另 一种则是其特有的可响应地磁极性的磁感应通路. 1994年, Hsu和Li [21] 在蜜蜂的滋养层细胞中发现富含超顺磁性磁铁矿, 且这些细胞受到神经系统的刺激, 因而推测蜜蜂的滋养层细 胞可能具有磁感应功能. 1995~2003年, Ernst和Lohmann [22] 在 一项关于一种迁徙龙虾(Panulirus argus)的研究中首次表明, 该龙虾是当时已报道的唯一可以同时感知磁场倾角和方向 等信息的无脊索动物, 其体内的磁铁矿颗粒可能是其感磁的 关键. ...
... Magnetic nanoparticles are presented in antennae, head, thorax and abdomen of young and adult workers ( Chambarelli et al. 2008). The iron granules in the trophocytes are randomly distributed in workers and drones while they are clustered in queens (Hsu, Li 1993), suggesting a role in magnetoreception (Hsu, Li 1994;Hsu et al. 2007). It is clear that magnetoreceptors in honey bees have not been sufficiently studied. ...
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Different physical factors (electric and electromagnetic fields, magnetic field, gravity, and light) can negatively affect activities of honey bee (Apis mellifera L.) either inside or outside the hives, possibly causing damage to bee colonies. In this paper, previous studies are reviewed to shed more light on the effects of these factors on honey bees, and to provide suggestions for additional investigations. Comb building, waggle dance, flight, and navigation have gained more attention than other activities. Also, worker bees have been studied more than drones and queens, and especially adults more than immature stages. Productivity aspects of bee colonies and biological parameters have not been the focus of most studies. Effects of the reviewed physical factors on bee-parasite interactions have gained little attention. The possibility of considering these physical factors as a serious hazard to honey bees is discussed. It seems that the field of honey bee physics is open for future investigations with focus on bee-parasite and bee-environment interactions.
... The gravireceptors in terrestrial insects consist of hair plates, clavate sensillae, trocholites, statolithic organs; those in aquatic animals consist of statocysts, whose shifting is registered by neurons of mechanoreceptive hairs [8,52]. Magnetic field sense of insects is mediated by receptors responding to magnetic iron dislocation with granules of iron oxide situated in oenocytes and cells of the fat body [53]. ...
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The role of intermediate substrates represented by morphological structures or chemical compounds located between the information carrier (stimulus) and the dendrite receptor membrane of insect sense organs is considered an example of olfactory, visual, mechanical, hygro-, and thermoreceptors. Intermediate substrates in olfactory sensillae are represented by their cuticular regions, pores or pore-tubular system, sensillum lymph, and pheromone-binding proteins. Intermediate structures also imply articular membrane (mechanoreceptor hairs), tympanic membrane (hearing organs), mineral statoliths (gravity receptors), iron oxide nanoparticles (magnetic field receptors), matrix surrounding the dendrites (hygroreceptors), microparticles associated with the dendrite membrane (thermoreceptors), and nonsclerotized mesocuticle (infrared receptors). There are two stages in propagation of a signal that is perceived by sense organs of most modalities: (1) before a signal contacts the peripheral environment (substance or structure) and (2) after a signal contacts the peripheral environment. Besides, a signal of one modality on the first stage of its propagation can be replaced by a signal of another modality at the second stage of propagation, as, for example, in hygro- or thermoreceptors, since the primary stimulus (moisture, heat/cold, or infrared radiation) is replaced by a mechanical effect on the dendrite membrane of its peripheral environment. The mechanisms of signal modality substitution in many sense organs, as well as the role of odorant-binding proteins and pore tubules in olfactory sensillae, have not been fully elucidated and require further investigation. The article is avaiable at Springer Nature Shared https://rdcu.be/ceZ1P
... Honeybees possess magnetite crystals in their fat body cells and they present magnetic remanence (Gould et al., 1978;Keim et al.,2002). These magnetite structures are active parts of the honeybees (Hsu and Li 1994;Hsu et al., 2007). Honeybees can communicate through chemical and acoustical means (Winston, 1991 andTautz, 2008). ...
... Furthermore, insects can also track their orientation with respect to the Earth's magnetic field (Fig. 2d;Collett and Baron 1994;Guerra et al. 2014;Dreyer et al. 2018;Fleischmann et al. 2018)) which is largely stationary, but is likely much less accurate than a celestial compass (Mouritsen 2018). Insects sense their bearing with respect to the magnetic North-South axis either through trophocyte cells containing super-paramagentic magnetite that change activity relative to an induced magnetic field (Hsu and Li 1994;Hsu et al. 2007), and/or crypotchrome activity in the visual pathways (Gegear et al. 2008;Phillips et al. 2010;Reppert et al. 2010). ...
Article
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Animals travelling through the world receive input from multiple sensory modalities that could be important for the guidance of their journeys. Given the availability of a rich array of cues, from idiothetic information to input from sky compasses and visual information through to olfactory and other cues (e.g. gustatory, magnetic, anemotactic or thermal) it is no surprise to see multimodality in most aspects of navigation. In this review, we present the current knowledge of multimodal cue use during orientation and navigation in insects. Multimodal cue use is adapted to a species’ sensory ecology and shapes navigation behaviour both during the learning of environmental cues and when performing complex foraging journeys. The simultaneous use of multiple cues is beneficial because it provides redundant navigational information, and in general, multimodality increases robustness, accuracy and overall foraging success. We use examples from sensorimotor behaviours in mosquitoes and flies as well as from large scale navigation in ants, bees and insects that migrate seasonally over large distances, asking at each stage how multiple cues are combined behaviourally and what insects gain from using different modalities.
... Based on the amount of magnetic material, the respective authors suggested, where the magnetic compass might be located. In honeybees, the abdomen has attracted a lot of attention (e.g., Hsu and Li 1994), but, at the same time, received serious criticism (Nichol et al. 1995). It has remained an open question whether the honeybee abdomen actually plays a crucial role in magnetoreception or has a function as waste storage for dietary iron (Shaw et al. 2018). ...
Article
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The use of information provided by the geomagnetic field (GMF) for navigation is widespread across the animal kingdom. At the same time, the magnetic sense is one of the least understood senses. Here, we review evidence for magnetoreception in Hymenoptera. We focus on experiments aiming to shed light on the role of the GMF for navigation. Both honeybees and desert ants are well-studied experimental models for navigation, and both use the GMF for specific navigational tasks under certain conditions. Cataglyphis desert ants use the GMF as a compass cue for path integration during their initial learning walks to align their gaze directions towards the nest entrance. This represents the first example for the use of the GMF in an insect species for a genuine navigational task under natural conditions and with all other navigational cues available. We argue that the recently described magnetic compass in Cataglyphis opens up a new integrative approach to understand the mechanisms underlying magnetoreception in Hymenoptera on different biological levels.
... These data agreed with FCC, (1999), Hsu, and Li (1994), Harst, et al. (2006), Stever, et al. (2007, Kumar, et al. (2010), Sharma and Kumar (2010), Sainudeen (2011), Kumar et al. (2013) and Shepherd et al. (2019) ...
Article
Many creatures in nature, including butterflies, newts, and mole rats, use the Earth's inherent magnetic field for navigation. They use magnetic field lines and variations in field intensity to determine their geographical position. This paper seeks to apply similar techniques to measure the positions of individual ferromagnetic objects found all around us in everyday life. Ferromagnetic objects have inherent magnetic fields around them. We show here that the magnetic field variation around a ferromagnetic object can be modeled using purely the geometry of the object under consideration. By exploiting this model, the position of the object can be measured quite accurately using a small inexpensive magnetic sensor. Further, the use of just one additional redundant magnetic sensor can eliminate the need to calibrate the position measurement system. As demonstrated in the paper through a series of experimental results, the developed measurement system is applicable to accurate position measurement of small and large ferromagnetic objects, including cars on highways, oscillating pistons in internal combustion engines, pneumatic cylinders, hydraulic cylinders, as well as moving parts in many machines.
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The design of bifunctional magnetic luminescent nanomaterials containing Fe3O4 functionalized with rare earth ion complexes of calixarene and β-diketonate ligands is reported. Their preparation is accessible through a facile one-pot method. These novel Fe3O4@calix-Eu(TTA) (TTA = thenoyltrifluoroacetonate) and Fe3O4@calix-Tb(ACAC) (ACAC = acetylacetonate) magnetic luminescent nanomaterials show interesting superparamagnetic and photonic properties. The magnetic properties (M-H and ZFC/FC measurements) at temperatures of 5 and 300 K were explored to investigate the extent of coating and the crystallinity effect on the saturation magnetization values and blocking temperatures. Even though magnetite is a strong luminescence quencher, the coating of the Fe3O4 nanoparticles with synthetically functionalized rare earth complexes has overcome this difficulty. The intramolecular energy transfer from the T1 excited triplet states of TTA and ACAC ligands to the emitting levels of Eu(3+) and Tb(3+) in the nanomaterials and emission efficiencies are presented and discussed, as well as the structural conclusions from the values of the 4f-4f intensity parameters in the case of the Eu(3+) ion. These novel nanomaterials may act as the emitting layer for the red and green light for magnetic light-converting molecular devices (MLCMDs).
Article
Control over magnetite (Fe3O4) formation is difficult to achieve in synthetic systems without using non-aqueous media and high temperatures. In contrast, Nature employs often intrinsically disordered proteins to tightly tailor the size, shape, purity, and organization of the nanocrystals to optimize their magnetic properties. Inspired by such “flexible polyelectrolytes,” here random copolypeptides having different amino acid compositions are used as control agents in the bioinspired coprecipitation of magnetite through a ferrihydrite precursor, following a recently developed mineralization protocol. Importantly, the copolypeptide library is designed such that the amino acid composition can be optimized to simultaneously direct the size of the nanoparticles as well as their dispersibility in aqueous media in a one-pot manner. Acidic amino acids are demonstrated to regulate the crystal size by delaying nucleation and reducing growth. Their relative content thus can be balanced to tune between the superparamagnetic and ferrimagnetic regimes, and high contents of negatively charged amino acids result in colloidal stabilization of superparamagnetic nanoparticles at high pH. Conversely, with positively charged lysine-rich copolypeptides ferrimagnetic crystals are obtained which are stabilized at neutral pH and self-organize in chains, as visualized by cryo-transmission electron microscopy. Altogether, the presented findings give important insights for the future development of additive-mediated nanomaterial syntheses.
Chapter
This chapter discusses electroreceptors and magnetoreceptors. The chapter considers the morphology and physiology of both ampullary and tuberous electroreceptors, including several reviews. It is mentioned that ampullary receptors are tuned and respond to low-frequency stimuli, with best frequencies generally between 0.1 and 20 Hz. Electroreception is a primitive vertebrate character, found in the common ancestor of jawless and jawed vertebrates. Phylogenetic analysis of character traits indicates that the electrosenses of all of these animals are homologous, reflecting their common phylogenetic origin. All electroreceptors, whether primitive or derived, can be broadly classified to belong to one of two categories—ampullary or tuberous. Electrosensory receptors and primary afferents exhibit common mode noise, which has important implications for central processing of electrosensory information. Tuberous electroreceptors are tuned to higher frequencies, with best frequencies in the 0.1-1.0 kHz range. Similar to derived ampullary electroreceptors, tuberous electroreceptors appear in separate and distantly related families of teleost fishes, indicating that they have evolved independently in each lineage. Gymnotid tuberous receptors exhibit a fairly uniform morphology despite the existence of several different functional subtypes of receptor. Intracellular recordings from individual tuberous electroreceptors have yet to be successfully conducted, and a considerable amount remains to be learned about the physiology of transduction in these receptors. Despite the fact that the tuberous electroreceptors in the Mormyroidea (Mormyridae and Gymnarchidae) are not homologous to those of the gymnotids, the receptors show striking similarities in both morphology and physiological responses, presenting a striking case of parallel homoplasy. As in gymnotids, the tuberous electroreceptors of mormyrids can be differentiated into rapid–timing units and amplitude-coding units.
Article
Physiological Systems in Insects discusses the roles of molecular biology, neuroendocrinology, biochemistry, and genetics in our understanding of insects. All chapters in the new edition are updated, with major revisions to those covering swiftly evolving areas like endocrine, developmental, behavioral, and nervous systems. The new edition includes the latest details from the literature on hormone receptors, behavioral genetics, insect genomics, neural integration, and much more. Organized according to insect physiological functions, this book is fully updated with the latest and foundational research that has influenced understanding of the patterns and processes of insects and is a valuable addition to the collection of any researcher or student working with insects. There are about 10 quintillion insects in the world divided into more than one million known species, and some scientists believe there may be more than 30 million species. As the largest living group on earth, insects can provide us with insight into adaptation, evolution, and survival. The internationally respected third edition of Marc Klowden's standard reference for entomologists and researchers and textbook for insect physiology courses provides the most comprehensive analysis of the systems that make insects important contributors to our environment.
Article
There are about 10 quintillion insects in the world divided into more than 1 million known species, and some scientists believe there may be more than 30 million species. As the largest living group on earth, insects can provide us with insight into adaptation, evolution, and survival. The internationally respected 3e of Marc Klowden's standard reference for entomologists and researchers and textbook for insect physiology courses provides the most comprehensive analysis of the systems that make insects important contributors to our environment. Physiological Systems in Insects discusses the role of insect molecular biology, neuroendocrinology, biochemistry, and genetics in our understanding of insects. All chapters in the new edition are revised, and major revision in fast-moving areas includes the Endocrine, Developmental, Behavioral, and Nervous System chapters. This new edition includes the latest details from the literature on hormone receptors, behavioral genetics, insect genomics, neural integration, and much more. Organized according to insect physiological functions, this book is fully updated with the latest and foundational research that has influenced understanding of the patterns and processes of insects and is a valuable addition to the collection of any researcher or student working with insects. Third edition has been updated with new information in almost every chapter and new figures Includes an extensive up-to-date bibliography in each chapter for readers who need to pursue topics in more depth. Provides a glossary of common entomological and physiological terms.
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The studies were carried out during 2012-13 at G.B.P.U.A.&T. Pantnagar, Uttarakhand, India, to investigate the biology and behaviour of Apis mellifera L. under the influence of electromagnetic radiations which were emitted from mobile tower. On the basis of observations recorded, it was concluded that the area of egg, capped brood, open brood, pollen and bees-strength was marked increased in T1 (0 m, beneath the mobile tower) 23.334 cm2, 465.00 cm2, 143.833 cm2, 54.166 cm2 and 5,552.34 cm2, respectively in experimental period. The radiation was recorded with the help of R.F. meter expressed in terms of electric field, magnetic field and power density. The radiation was maximum in T1 (0 m, beneath the mobile tower) where, E (304.297 mV/m), B (541.22 μA/m) and S (302.913 mW/m2). The result indicated that no impact of electromagnetic radiations on area of honey, brood, larva, pollen and bees-strength during the experimental period.
Article
From the separating method by outer magnetic field the nanometer magnetite existing in the major lateral radula teeth of chiton Acanthochiton Rubrolinestus are extracted. Then by using the scanning electron microscope, the high resolution transmission electron microscopy, magnetic force microscopy and SQUID measurement instrument, the distribution of nanometer magnetite existing in the teeth, some physical characteristics of nanomagnetites including crystal structure, magnetic characteristics of nanomagnetites are studied. The results show that these nanometer magnetites are oblong sheetlike magnetites Fe3O4 with many little crystal grains with regular crystal structure in it, these nanomagnetites have single magnetic domain and show up good magnetic characteristics of single axis and single magnetic domain, they regularly distribute in the teeth, and so form special magnetic field in the radula of chiton. ©, 2015, Rengong Jingti Xuebao/Journal of Synthetic Crystals. All right reserved.
Article
In the following review the contemporary state of research on the principles of insect geomagnetic sensitivity is summarised along with a survey of results published since the beginning of the investigation. The experimental results are presented from the point of view of two dominant theoretical approaches. A dispersive and controversial character of recent experimental data making sufficient verification of either of the hypotheses impossible is suggested.
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Iron granules containing superparamagnetic magnetite act as magnetoreceptor for magnetoreception in honey bees. Biomineralization of iron granules occurs in the iron deposition vesicles of trophocytes and requires the participation of actin, myosin, ferritin2, and ATP synthase. The mechanism of magnetoreception in honey bees can be explored by suppressing the formation of iron granules. Toward this goal, we injected double-stranded RNA of ferritin2 and ferritin1 into newly emerged worker honey bees to knock down these genes via RNA interference. We confirmed that mRNA and protein production of the ferritins was inhibited, leading to immature iron granules. Downregulating ferritin2 and ferritin1, moreover, leads to different deposition morphology of 7.5-nm diameter iron particles, indicating that the two genes play different roles in the formation of iron granules in worker honey bees.
Chapter
If electrostatic forces define the chemical shape of our world, to a great degree it is the movement of charge that brings that world to life. The movement of charge is necessary for sensation, mental activity, muscular movement, and energy transduction by photosynthesis and metabolism, to name just several examples. When an electric field exists in either free space or a conducting medium, charges will move under the field’s influence. This movement of charge is the electric current. The flow of charge in a vacuum is familiar to most readers as the electron beam of a television or oscilloscope. Movement of charge is more familiar today in the solid state, whether in metal or polymer conductors or in semiconductors. It is probable that within this generation the cathode ray tube will be of only historical interest, having most likely been replaced by solid state display devices. Movement of charge in the solid state is generally impeded by the presence of the atomic and molecular structure that composes the material through which charge flows. We will review the physical principles of conduction through conductors and semiconductors and then delve much more deeply into the molecular particulars of conduction in substrates of biological interest in later chapters.
Chapter
In sechs Feldern der Oberschnabelhaut der Brieftaube befinden sich sensorische Nervenendigungen mit zweierlei eisenhaltigen Komponenten, die die Basis für die primären Rezeptorprozesse bei der Magnetfeldwahrnehmung darstellen könnten. Beim gegenwärtigen Stand der Forschung wird in einer interdisziplinären Zusammenarbeit von Neurobiologen und Geo-Materialwissenschaftlern versucht, mit Hilfe von ortsauflösenden physikalischen und immunhistologischen Methoden die quantitativen und qualitativen Beziehungen dieser komplexen Strukturkomponenten zueinander und zur perzipierenden Membran aufzuklären, um eine magnetische Funktionalität nachzuweisen. Damit könnte es zum ersten Mal gelingen, am Beispiel der Brieftaube ein magnetfeldempfindliches Organ im Tierreich zu identifizieren. Dieses ist die Grundlage für die Orientierung anhand von Magnetfeldparametern.
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An additional horizontal magnetic field is lethal for adult hornets and larvae. The juvenile hornets, however, are capable of adapting to the additional magnetic field. They build combs commencing in the regions of high field intensity, and proceeding in the direction of the field intensity decrease.
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Although the presence of magnetite in their tissues is correlated with the ability of different species to detect magnetic fields, proof that the magnetite is involved in magnetoreception has not yet been provided. Using the approach employed to localize and isolate magnetic particles in the yellowfin tuna, we found that single-domain magnetite occurs in chains of particles in tissue contained within the dermethmoid cartilage of adult chinook salmon,Oncorhynchus tshawytscha. The particles are present in sufficient numbers to provide the adult fish with a very sensitive magnetoreceptor system. Magnetite in the chinook can be correlated with responses to magnetic fields in a congeneric species, the sockeye salmon. Based on the presence of the chains of particles, we propose behavioral experiments that exploit the responses of sockeye salmon fry to magnetic fields to test explicit predictions of the ferromagnetic magnetoreception hypothesis.
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Magnetic grains isolated from magnetococcoid bacterial cells were studied by means of transmission electron microscopy, electron diffraction and electron microprobe analysis. Observed in situ the magnetic grains are each surrounded by an organic membrane and are usually found in a random array although “chains” are also seen. Electron diffraction confirms the magnetite mineralogy and provides additional evidence in favor of vacancies in the structure. Electron microprobe analysis shows the magnetite to be slightly titaniferous. Electron microscopy indicates that the grains, rather than being flake shaped, are parallelepiped crystals with a mean length of99.3 ± 8.7nm, a mean width of62.3 ± 6.1nm yielding a width-to-length ratio of 0.63. These data support the contention that the magnetic bacterial grains are single-domain crystals capable of producing a natural remanent magnetization in sediments.
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Although the mineral magnetite (Fe3O4) is precipitated biochemically by bacteria, protists, and a variety of animals, it has not been documented previously in human tissue. Using an ultrasensitive superconducting magnetometer in a clean-lab environment, we have detected the presence of ferromagnetic material in a variety of tissues from the human brain. Magnetic particle extracts from solubilized brain tissues examined with high-resolution transmission electron microscopy, electron diffraction, and elemental analyses identify minerals in the magnetite-maghemite family, with many of the crystal morphologies and structures resembling strongly those precipitated by magnetotactic bacteria and fish. These magnetic and high-resolution transmission electron microscopy measurements imply the presence of a minimum of 5 million single-domain crystals per gram for most tissues in the brain and greater than 100 million crystals per gram for pia and dura. Magnetic property data indicate the crystals are in clumps of between 50 and 100 particles. Biogenic magnetite in the human brain may account for high-field saturation effects observed in the T1 and T2 values of magnetic resonance imaging and, perhaps, for a variety of biological effects of low-frequency magnetic fields.
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Homing pigeons were equipped with a pair of small coils around their heads. Birds with an induced field of 0.6 gauss and the south magnetic pole up, oriented toward home normally under both sun and overcast. Birds with the polarity reversed oriented toward home when the sun was visible but often flew away from home under overcast.
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Bacteria, sharks, honey bees, and homing pigeons as well as other organisms seem to detect the direction of the earth's magnetic field. Indirect but reproducible evidence suggests that the bees and birds can also respond to very minute changes in its intensity. The mechanisms behind this sensitivity are not known. Naturally magnetic, biologically precipitated magnetite (Fe3O4) has been found in chitons, magnetotactic bacteria, honey bees, homing pigeons, and dolphins. Its mineralization in localized areas may be associated with the ability of these animals to respond to the direction and intensity of the earth's magnetic field. The presence of large numbers (approximately 10(8)) of superparamagnetic magnetite crystals in honey bees and similar numbers of single-domain magnetite grains in pigeons suggests that there may be at least two basic types of ferrimagnetic magnetoreceptive organelles. Theoretical calculations show that ferrimagnetic organs using either type of grain when integrated by the nervous system are capable of accounting for even the most extreme magnetic field sensitivities reported. Indirect evidence suggests that organic magnetite may be a common biological component, and may account for the results of numerous high field and electromagnetic experiments on animals.
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A wide range of animals are able to orient toward home when subjected to displacement-release experiments. When comparable experiments are performed on blindfolded humans, a similar ability emerges. Such goal-orientation does not result from following the complete journey on a mental map, nor is it influenced by cloud cover. Bar magnets worn on the head do seem to exert an influence.
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Honey bees orient to the earth's magnetic field. This ability may be associated with a region of transversely oriented magnetic material in the front of the abdomen. The magnetic moment apparently develops in the pupal state and persists in the adults.
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Single-domain magnetite crystals have been isolated and characterized from tissue located in a sinus within the dermethmoid bone of the skull of the yellowfin tuna, Thunnus albacares. Their chemical composition, narrow size distribution, and distinctive crystal morphology indicate that these crystals are biochemical precipitates. Experiments on the interaction between particles reveal the organization of the particles in situ and suggest a possible form for candidate magnetoreceptor organelles. The consistent localization of such particles with similar arrangement within the dermethmoids of this and other pelagic fishes suggests that the ethmoid region is a possible location for a vertebrate magnetic sense organ.
  • C Y Hsu
  • J L Kirschvink
  • Evidence
  • Strandings For
  • Geomagnetic
  • In Cetaceans
  • D A Kuterbach
  • Iron-Containing
  • In
  • Honeybee
  • S Mann
  • Ultrastructure Organization
  • Biogenic
  • From
  • Oncorhynchus-Nerka - Implications For Salmon
  • Magnetoreception
Magnetite Biomineralization and Magnetoreception in Organisms: A New Biomagnetism
  • A Perry
Magnetite Biomineralization and Magnetoreception in Organisms: A New Biomagnetism
  • W F Towne