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Antennal Movements in the Honeybee: How Complex Tasks are Solved by a Simple Neuronal System
Abstract
The antennae of insects are multisensory receptor organs for the perception of chemical and mechanical stimuli. In many insect groups the antennae are movable and display specific responses to various stimuli, even to moving targets which are perceived by the compound eyes. In hymenoptera, like bees and ants, the antennae can be used for communication by transmitting tactile signals and receiving multisensory information. The amount of information which can be conveyed by antennation from a sender to a receiver seems to be limited (Hölldobler & Wilson 1990) and plays an important role especially in recruiting other individuals from the same colony (Hölldobler & Wilson 1978). Also the exchange of food and “greeting” between individuals is accompanied by distinct antennation.
... Four muscles in the head enable rotatory movements of the scapus in the ball and socket joint between the head capsule and the scapus. The ¯agellum and the pedicellus are moved by two muscles in the scapus, an extensor and a ¯exor muscle (Erber and Pribbenow 2000). The ¯exor muscle is comprised of two groups and shows fast and slow contractions. ...
... The fast contractions are characterised by large muscle potentials . Activity of the fast ¯agellum ¯exor muscle induces large and rapid movements of the ¯agellum, which dominate scanning behaviour when the bee touches an object (Erber and Pribbenow 2000 ). The antennal muscles are innervated by motoneurons whose somata and dendrites are located in the dorsal lobe of the protocerebrum . ...
... In addition, these large ®bres are innervated by a single motoneuron. We conclude from these ®ndings that the ventral ¯exor ®bres produce the large muscle potentials, which in turn lead to the rapid ¯exion movements of the ¯agellum (Erber and Pribbenow 2000). The large muscle potentials, on the other hand, are controlled by the motoneuron which is shown inFig. ...
Antennal movements of the honey bee can be conditioned operantly under laboratory conditions. Using this behavioural paradigm we have developed a preparation in which the activity of a single antennal muscle has been operantly conditioned. This muscle, the fast flagellum flexor muscle, is innervated by an identified motoneuron whose action potentials correlate 1:1 with the muscle potentials. The activity of the fast flagellum flexor muscle was recorded extracellularly from the scapus of the antenna. The animal was rewarded with a drop of sucrose solution whenever the muscle activity exceeded a defined reward threshold. The reward threshold was one standard deviation above the mean spontaneous frequency prior to conditioning. After ten conditioning trials, the frequency of the muscle potentials had increased significantly compared to the spontaneous frequency. The conditioned changes of frequency were observed for 30 min after conditioning. No significant changes of the frequency were found in the yoke control group. The firing pattern of the muscle potentials did not change significantly after conditioning or feeding. Fixing the antennal joints reduces or abolishes associative operant conditioning. The conditioned changes of the frequency of muscle potentials in the freely moving antenna are directly comparable to the behavioural changes during operant conditioning.
... Sucrose stimuli can be perceived by taste hairs on the antennae, the proboscis, and the tarsi [21,34]. The antennae respond to sucrose stimulation of antennal taste hairs with directed movements [4,11,12]. This antennal motor pattern is an exploratory response for locating and assessing a gustatory stimulus by antennal scanning. ...
... This antennal motor pattern is an exploratory response for locating and assessing a gustatory stimulus by antennal scanning. The fast flagellum flexor (FFF) muscle controls rapid antennal scanning movements which are used to probe stimuli with repeated contacts [12,26]. After having located and evaluated the sucrose source, the bee can respond with an extension of its proboscis (proboscis extension response, PER). ...
... Thus, unlike in the M17 muscle response, the concentration-dependent response properties of sucrose-sensitive sensory cells are not reflected by FFF muscle responses. Sucrose-induced antennal movements and antennal scanning of sucrose solution droplets, which is dominated by FFF muscle activity, depend on sucrose concentration [12,17]. It appears that such correlation cannot be detected with a single, short, passive sucrose stimulus as used in the present study. ...
Sucrose-induced antennal and proboscis motor responses of the honey bee were comparatively studied using muscle responses. The activity of the proboscis muscle responses was correlated with sucrose stimulus concentration, but that of antennal muscle responses was not. Both responses habituated following repetitive stimulation with a low sucrose concentration and dishabituated upon stimulation with a high sucrose concentration. Despite the different response properties of the responses, their habituation kinetics were indistinguishable. The absence of sensory adaptation was confirmed by taste hair recordings. The potential for habituation was related to the functions of the responses studied. The exploratory antennal response used for continuous sampling of the environment habituated to a smaller extent than the appetitive proboscis response.
... Similarly, quantitative assessment of antennae movement with high temporal and spatial resolution might yield insight into the relationship between the stimulus, the behavior, and internal state of the animal. Indeed previous work has shown how the antennal movements contain a rich amount of information about honey bee tracking of the environment and how the movements change with learning [32][33][34][35][36][37][38] . ...
Many scientifically and agriculturally important insects use antennae to detect the presence of volatile chemical compounds and extend their proboscis during feeding. The ability to rapidly obtain high-resolution measurements of natural antenna and proboscis movements and assess how they change in response to chemical, developmental, and genetic manipulations can aid the understanding of insect behavior. By extending our previous work on assessing aggregate insect swarm or animal group movements from natural and laboratory videos using video analysis software SwarmSight, we developed a novel, free, and open-source software module, SwarmSight Appendage Tracking ( SwarmSight.org ) for frame-by-frame tracking of insect antenna and proboscis positions from conventional web camera videos using conventional computers. The software processes frames about 120 times faster than humans, performs at better than human accuracy, and, using 30 frames-per-second videos, can capture antennal dynamics up to 15 Hz. We used the software to track the antennal response of honey bees to two odors and found significant mean antennal retractions away from the odor source about 1 s after odor presentation. We observed antenna position density heat map cluster formation and cluster and mean angle dependence on odor concentration.
... Similarly, quantitative assessment of antennae movement with high temporal and spatial resolution might yield insight into the relationship between the stimulus, the behavior, and internal state of the animal. Indeed previous work has shown how the antennal movements contain a rich amount of information about honey bee tracking of the environment and how the movements change with learning 32,33,34,35,36,37,38 . ...
Many scientifically and agriculturally important insects use antennae to detect the presence of volatile chemical compounds and extend their proboscis during feeding. The ability to rapidly obtain high-resolution measurements of natural antenna and proboscis movements and assess how they change in response to chemical, developmental, and genetic manipulations can aid the understanding of insect behavior. By extending our previous work on assessing aggregate insect swarm or animal group movements from natural and laboratory videos using the video analysis software SwarmSight, we developed a novel, free, and open-source software module, SwarmSight Appendage Tracking (SwarmSight.org) for frame-by-frame tracking of insect antenna and proboscis positions from conventional web camera videos using conventional computers. The software processes frames about 120 times faster than humans, performs at better than human accuracy, and, using 30 frames per second (fps) videos, can capture antennal dynamics up to 15 Hz. The software was used to track the antennal response of honey bees to two odors and found significant mean antennal retractions away from the odor source about 1 s after odor presentation. We observed antenna position density heat map cluster formation and cluster and mean angle dependence on odor concentration. © 2017, Journal of Visualized Experiments. All rights reserved.
... Recognizing that all of these stimuli may be important, we decided to begin our investigation by determining if resin foragers are particularly sensitive to tactile stimuli such as gaps, crevices and rough surfaces. The bees' antennae are an integral tool for this type of information assessment (Erber and Pribbenow 2001; Johnson 2008). Bees, and specifically some resin handlers and foragers, have been noted to detect crevices by inserting the antenna into gaps in nest architecture (Nakamura and Seeley 2006). ...
Honeybees harvest and use plant resins in a mixture called propolis to seal cracks and smooth surfaces in the nest architecture.
Resins in the nest may be important in maintaining a healthy colony due to their antimicrobial properties. This study had
two main objectives: (1) Provide initial insight on the learning capabilities of resin foraging honeybees; (2) analyze the
sensitivity of resin foraging honeybees to tactile stimuli to elucidate its possible role as a mechanism behind resin foraging.
The first objective provides insight into the phenotype of these bees as compared to other forager types, while the second
creates a starting point for further work on behavioral mechanisms of resin foraging. Using tactile proboscis extension response
conditioning, we found that resin foragers learned to associate two different tactile stimuli, the presence of a gap between
two plates and a rough sandpaper surface, with a sucrose reward significantly better than pollen foragers. The results of
differential tactile conditioning exhibited no significant difference in the ability of resin foragers to discriminate between
smooth and rough surfaces as compared to pollen foragers. We also determined that the sucrose response thresholds (SRTs) of
returning resin foragers were lower compared to returning pollen foragers, but both resin foragers and pollen foragers learned
a floral odor equally well. This is the first study to examine SRTs and conditioning to tactile and olfactory stimuli with
resin foraging honeybees. The results provide new information and identify areas for future research on resin collectors,
an understudied foraging phenotype.
Keywords
Apis mellifera
-Propolis-Proboscis extension response-Conditioning-Response thresholds
... Since the nest interior is completely dark, bees must rely on non-visual senses to detect stimuli within the nest environment. The bees' antennae are an integral tool for this type of information assessment (Erber and Pribbenow, 2001; Johnson, 2008). Bees, and specifically some resin handlers and foragers, have been noted to detect crevices by inserting the antenna into gaps in nest architecture (Nakamura and Seeley, 2006). ...
Social immunity, which describes how individual behaviors of group members effectively reduce disease and parasite transmission
at the colony level, is an emerging field in social insect biology. An understudied, but significant behavioral disease resistance
mechanism in honey bees is their collection and use of plant resins. Honey bees harvest resins with antimicrobial properties
from various plant species and bring them back to the colony where they are then mixed with varying amounts of wax and utilized
as propolis. Propolis is an apicultural term for the resins when used by bees within a hive. While numerous studies have investigated
the chemical components of propolis that could be used to treat human diseases, there is a lack of information on the importance
of propolis in regards to bee health. This review serves to provide a compilation of recent research concerning the behavior
of bees in relation to resins and propolis, focusing more on the bees themselves and the potential evolutionary benefits of
resin collection. Future research goals are also established in order to create a new focus within the literature on the natural
history of resin use among the social insects and role that propolis plays in disease resistance.
The different forms of tactile antennal learning in the honey bee are based on operant activity of the antennae. Flexible motor programs of the antennae are used for monitoring multimodal signals in the space around the head. Bees can learn the three-dimensional location of an object within the reach of the antennae by touching it frequently. During operant conditioning bees learn that antennal contacts with an object lead to a sucrose reward. Operant antennal conditioning is side specific and bees learn to discriminate between different objects. Operant antennal conditioning can be reduced to conditioning of the activity of the fast flagellum flexor muscle (FFF muscle) which is innervated by a single motoneuron. Using the proboscis extension reflex (PER) bees can be conditioned to discriminate between different surface structures, forms, sizes and locations of objects. The characteristics of PER conditioning are similar to those of olfactory PER conditioning under laboratory conditions. Mechanoreceptors on the antennal tip are used for surface discrimination. Bees that discriminate between different surface structures show characteristic antennal scanning movements.
Insect antennae are multisensory probes which are used in many behavioural contexts, receiving sensory information from various modalities. Mechanoreceptors signal exteroreceptive cues like contact with another surface, flow or vibration of the surrounding medium, and proprioreceptive cues like joint angles and cuticular strain due to bending. Antennae can actively search the surrounding space, scan objects for surface properties, or transfer information between conspecifics by means of physical contact.We review insect behaviours involving antennal mechanosensory information, and passive or active antennal movements. Chemo- and thermoreception are only covered to the extent to which there is a direct connection to tactile sensing. Particular emphasis is given to model systems of invertebrate neuroscience, i.e. cockroach, cricket, locust, stick insect and the honeybee. For comparison, corresponding behaviours of crayfish and lobsters are discussed.The six sections deal with (a) the antennal motor system, kinematics, biomechanics, musculature and efferent innervation; (b) the sensory physiology of antennal mechanoreceptors, including mechanosensitive hairs, campaniform sensilla, chordotonal organs and stretch receptors; (c) the neuroanatomy of the brain structures processing antennal mechanosensory information, notably the deutocerebrum; (d) the neurophysiology of the afferents, local and descending interneurons, and motoneurons; (e) the behavioural physiology of passive and active sensing, including reflex behaviours, graviception, steering, escape, tactile exploration and localisation, pattern recognition, tactile learning and communication; and (f) some engineering aspects regarding the construction of artificial tactile antennae
Honigbienen werden im Freiland operant konditioniert, wenn ein spezifisches Verhalten Belohnung erfährt, z.B. das erfolgreiche Aufsuchen einer Futterquelle oder die Heimkehr zum Stock. Ziel der vorliegenden Arbeit war es, ein operantes Lernparadigma für Bienen unter Laborbedingungen zu entwickeln und auf seine Charakteristika zu untersuchen. Bienen können unter Laborbedingungen lernen, kleine Plättchen vermehrt mit ihren Antennen abzutasten, wenn die häufige Berührung belohnt wird. Sie lernen in einer differentiellen Lernsituation belohnte Plättchen von unbelohnten Plättchen zu unterscheiden und tasten das konditionierte Plättchen häufiger ab. Die Plastizität des operanten Lernens konnte durch Umlernversuche zwischen dorsaler und ventraler Platte demonstriert werden. Die Akquisition operanten Lernens erreicht schneller ihre Sättigung als beim unbelohnten motorischen Lernen und langsamer als beim taktilen oder olfaktorischen Konditionieren von Bienen. Durch seitenspezifische Konditionierung von Antennenbewegungen konnte gezeigt werden, dass operantes Lernen spezifisch für die konditionierte Antenne ist. Die Hypothese, dass operantes Lernen von Antennenbewegungen auf den Dorsallobus begrenzt ist, bleibt bestehen. Operantes Konditionieren lässt sich an einem im Abtasten sehr dominanten Antennenmuskel (fast flagellum flexor) zeigen, der von einem einzelnen identifizierten Motoneuron innerviert wird. Der Effekt der Konditionierung liegt in einer Erhöhung der Häufigkeit von Aktionspotentialen. Mögliche Ursachen der erhöhten Feuerrate des Motoneurons durch die Konditionierung werden diskutiert. Die Fixierung der antennalen Gelenke reduziert oder verhindert operantes Lernen im elektrophysiologischen Präparat. Daraus ergaben sich Ausschaltexperimente, die eine weitere Eingrenzung der mechanosensorischen Rückkopplung auf das operante Lernen ermöglichten. Die Sinneshaarfelder am Kugelgelenk der Antenne haben keinen signifikanten Einfluss auf das operante Positionslernen. Bienen, die sich im Lernerfolg nach taktiler Oberflächenkonditionierung unterschieden, zeigten schon vorher Unterschiede in der Abtastaktivität. Mögliche Zusammenhänge von Abtastaktivität eines Tieres und der Modulation durch biogene Amine werden erläutert. Abtastverhalten und Antworteigenschaften auf Zuckerwasserreize wurden untersucht. Bienen, die schon auf einen Wasserstimulus mit einem Rüsselreflex reagierten, zeigten über kurze Zeit eine höhere ventrale Abtastaktivität als Bienen, die erst auf Zuckerwasser reagierten. Erklärungsansätze zur unterschiedlichen Abtastaktivität von Bienen mit verschiedenen Reaktionsschwellen werden gesucht.
Honeybees learn and discriminate excellently between different surface structures and different forms of objects, which they scan with their antennae. The sensory plate on the antennal tip plays a key role in the perception of mechanosensory and gustatory information. It is densely covered with small tactile hairs and carries a few large taste hairs. Both types of sensilla contain a mechanoreceptor, which is involved in the antennal scanning of an object. Our experiments test the roles of the mechanoreceptors on the antennal tip in tactile antennal learning and discrimination. Joints between head capsule and scapus and between scapus and pedicellus enable the bee to perform three-dimensional movements when they scan an object. The role of these joints in tactile antennal learning and discrimination is studied in separate experiments. The mechanoreceptors on the antennal tip were decisive for surface discrimination, but not for tactile acquisition or discrimination of shapes. When the scapus-pedicellus joint or the headcapsule-scapus joint was fixed on both antennae, tactile learning was still apparent but surface discrimination was abolished. Fixing both scapi to the head capsule reduced tactile acquisition.
Honeybees are shown to be able to detect, learn, and discriminate between microsculptured epidermes of flower petals. The sensilla trichodea at the tips of the bees' antennae are in the same size range as the microsculptural features of the petals (ca. 10 mum), which presumably deflect these mechanoreceptive sensilla in characteristic ways. Honeybees were trained to associate reward with one floral texture and to choose that over another. Further, the bees also recognized differences in textures at different ends of petals of the same species. The phenomenon is significant in that it suggests another way in which insect pollinators can discriminate between the flowers of different plant species and so act as species isolators. Also, the microsculptural patterns differ from one end of a petal to the other and, therefore, can be used as nectar-guides by foraging bees. This study presents a previously unreported conditioned response to texture by insects and shows the functional significance of a floral character used in plant taxonomy.
Honeybees respond with antennal reflexes to stimuli of different modalities when kept in the restricted conditions of a laboratory experiment, The animals react with direction-specific antennal responses to vertically moving stripe patterns. Stripe patterns with velocities between 25-degrees/s and 60-degrees/s evoke maximum responses. The minimum pattern size is 55-degrees x 35-degrees relative to the bee eye. Unilateral stimulation with the pattern elicits ipsilateral antennal responses. Bees respond to olfactory stimuli with directed scanning movements of both antennae. The magnitude of the response depends on the logarithm of the odour concentration. Different classes of odours evoke different responses. Bees touch objects briefly and frequently with their antennae. The median contact duration is < 10 ms; the frequency of contact ranges from < 3/min to > 300/min. The mechanical antennal response shows a high degree of plasticity. Bees appear to learn the position of an object and scan the area and contours of the object for at least 2 min after it has been removed. The antennal reflexes of the bee serve as tools for studying signal processing, neuromodulation, sensitisation and learning in different sensory systems.
DURING classical conditioning, animals learn to associate a neutral stimulus with a meaningful, or unconditioned, stimulus. The unconditioned stimulus is essential for forming associations, and modifications in the processing of the unconditioned stimulus are thought to underlie more complex learning forms1-4. Information on the neuronal representation of the unconditioned stimulus is therefore required for understanding both basic and higher-order features of conditioning. In honeybees, conditioning of the proboscis extension reflex occurs after a single pairing of an odour (conditioned stimulus) with food (unconditioned stimulus)5,6 and shows several higher-order features of conditioning6-8. I report here the identification of an interneuron that mediates the unconditioned stimulus in this associative learning. Its physiology is also compatible with a function in complex forms of associative learning. This neuron provides the first direct access to the cellular mechanisms underlying the reinforcing properties of the unconditioned stimulus pathway.
The movement of the antennae of bees was optically analysed under laboratory conditions during visual conditioning with a moving stripe pattern. The unconditioned antennal movement towards the midline of the head in response to a sugar-water stimulus to one antenna becomes a conditioned response with the stripe movement as the conditioned stimulus.
Bees can be conditioned to the ventral to dorsal movement of the stripe pattern. Conditioning to the dorsal to ventral direction leads to an increase of the reaction to ventral-dorsal movement (Fig. 2).
A number of bees already responds with significant antennal movements to the moving stripe stimulus in the ventro-dorsal plane of motion before conditioning. These bees cannot be conditioned to the visual stimulus (Fig. 3A).
The conditioned reaction is extinct after about 5 tests without a reward (Fig. 3B).
No specific conditioning effects can be shown for the anterior to posterior direction of stripe movement (Fig. 4).
Control experiments (pseudoconditioning and sensitization) indicate that there are response changes due to feeding with sugar-water. These unspecific response variations are significantly different from the responses after conditioning (Fig. 6).
Associative and nonassociative learning in this preparation opens the possibility of studying the underlying neural processes.
The biogenic amines serotonin (5HT) and octopamine (OA) exist in the bee and can modulate neuronal activity and behaviour. 5HT-like and OA-like immunoreactivities can be found in most neuropils of the brain. Binding sites for the two amines are also present in most brain neuropils. The highest density of binding sites for [3H]serotonin and [3H]octopamine was found in the mushroom bodies. In some brain areas, especially the mushroom bodies, mismatches exist between binding sites and immunoreactivities, suggesting that the two amines also bind to neuropils which are not directly innervated by 5HT-like or OA-like immunoreactive neurons. The action of the two amines on behaviour in the bee is antagonistic. In the antennal pathway, proboscis and antennal responses to olfactory and gustatory stimuli are enhanced by OA and reduced by 5HT. In olfactory conditioning experiments, storage and retrieval of the learned signal can be enhanced by OA and reduced by 5HT. The specificity of these effects depends on the site of amine application in the neuropil. In the visual system the direction specificity of the visual antennal response is enhanced by OA and reduced by 5HT after topical application or injection into the lobula, the third optic ganglion. Correlates for the behavioural modulation can be found in higher-order visual interneurons. While OA application can mimic the stimulation of the bee with sugar water, the behavioural conditions leading to the release of 5HT are not yet known.
Airborne sound signals emitted by dancing bees (Apis mellifera) play an essential role in the bees' dance communication. It has been shown earlier that bees can learn to respond to airborne sounds in an aversive conditioning paradigm. Here we present a new training paradigm. A Y-choice situation was used to determine the frequency range and amplitude thresholds of hearing in bees. In addition, spontaneous reactions of bees to airborne sound were observed and used to determine thresholds of hearing. Both methods revealed that bees are able to detect sound frequencies up to about 500 Hz. The hearing threshold is 100–300 mm/s peak-to-peak velocity and is roughly constant over the range of detectable frequencies. The amplitude of the signals emitted in the dance language is 5 to 10 times higher, so we can conclude that bees can easily detect the dance sounds.
1.
The effects of the biogenic amines serotonin and octopamine on motion-sensitive neurons in the lobula of the honey bee were analysed electrophysiologically. Single cell activity was recorded intracellularly during application of amines. Field potentials in the lobula were recorded to measure the effects on populations of motion-sensitive neurons.
2.
Serotonin and octopamine modulate the response properties of motion-sensitive neurons in the lobula in a functionally antagonistic way.
3.
The application of serotonin, in most cases, reduces background activity as well as responses to moving stripe patterns by motion-sensitive lobula neurons. The direction specificity can also decrease after serotonin application. In accordance with the single cell recordings, the amplitudes of lobula field potentials evoked by moving stripe patterns are also reduced by application of serotonin.
4.
Octopamine leads to an increase in the amplitude and the initial slope of field potentials evoked by moving stripe patterns. However, there were no uniform effects at the single cell level after octopamine application.
5.
The modulatory effects of serotonin and octopamine on motion-sensitive neurons correlate well with some behavioral modifications elicited by these substances (Erber et al. 1991; Erber and Kloppenburg, companion paper).
1.
Am Thorax fixierte Bienen fliegen in einem Windkanal und verkleinern mit zunehmender Anstrmung von vorne die Flgelschlagamplitude im Mittel um 39 bei 8,5 m/sec. Diese Abnahme ist nur zum kleinsten Teil mechanisch verstndlich, denn an Bienen im Rauschflug beobachtet man nur eine Abnahme der Flgelschlagamplitude um nur 6,5. Antennenlose Bienen, welche von vorn symmetrisch angestrmt werden, verringern ihre Flgelschlagamplitude wesentlich weniger als normale, jedoch etwas strker als Bienen im Rauschflug. Die Antennen funktionieren als Meorgane, die eine Flugeigengeschwindigkeit melden.
2.
Diese Funktion der Antennen lt sich auch an frei fliegenden Bienen nachweisen.
3.
Auch die Antennenhaltung hngt von der Flugeigengeschwindigkeit ab. Im Windkanal fhren die Bienen bei steigender Anstrmgeschwindigkeit ihre Antennen immer enger zur Mitte zusammen. Sie verringern aktiv den Antellwinkel der Geiel. Das gleiche geschieht im freien Flug bei steigender Flugeigengeschwindigkeit.
4.
Die Einstellung der Antennen gem der Anstrm- bzw. Flugeigengeschwindigkeit setzt ein intaktes Johnstonsches Organ voraus. Dieses ist der gesuchte Strmungsrezeptor. Alle anderen Stellen knnen von der Anstrmung ausgenommen werden, ohne da sich dadurch die Antennenhaltung entsprechend der Anstrmgeschwindigkeit ndert. Die Antennenhaltung wird nur nach den Informationen des Johnstonschen Organs gesteuert.
5.
Der vorige Punkt lt sich durch Versuche beweisen, bei denen nur die Antennen durch eine wechselnde Magnetkraft zum Schwingen gebracht bzw. nach auen gedrckt werden. Die fixiert fliegende Biene stellt die Antennen dann genau so ein, wie whrend einer Anstrmung.
6.
Ein Johnstonsches Organ steuert immer nur die Stellung seiner Antenne.
7.
Die Resonanzfrequenz der Antennengeiel betrgt 285 Hz bei dorsoventraler, 274 Hz bei lateraler Schwingungsrichtung der Geiel. Die Werte liegen nahe bei der Flgelschlagfrequenz der Arbeitsbiene.
8.
Die Geiel biegt sich bei der Belastung an der Spitze besonders stark ventrad, viel weniger stark dorsad, sie ist also fr eine Belastung, wie sie im Flug auftritt, gnstig gebaut.
9.
Jede Deformation der Geiel, jede Schwingung der Geiel lst eine krftige, efferente, elektrische Aktivitt aus. Die afferente elektrische Aktivitt kann nur an Prparaten studiert werden, deren Antennennerv durchtrennt wurde.
Elektrophysiologischer Teil
10.
Bei einer Deformation der Geiel erhlt man eine hohe spikeartige Aktivitt, deren Amplitude und Frequenz von der Gre der Deformation abhngt. Die Potentiale gehen auf eine Erregung der Mechanorezeptoren der Geiel zurck. Eine stndige Verbiegung des Flagellums gegen den Pedicellus lt bei der Ableitung mit Stahlnadelmikrolektroden keine tonische Aktivitt erkennen, die im Johnstonschen Organ entstanden sein knnte.
Afferentes Geschehen
11.
Werden der Geiel Sinusschwingungen aufgezwungen, so erhlt man vom Johnstonschen Organ und den ableitenden Nerven stammende Potentiale. Bei Frequenzen ber 15 Hz und unter 150 Hz solche der doppelten Frequenz.
12.
Am empfindlichsten ist das Johnstonsche Organ fr Schwingungen von 200–350 Hz. Hier gengen Schwingungsamplituden des Flagellums von 20 sec, um eine sich vom Strpegel abhebende elektrische Aktivitt zu erhalten.
13.
Whrend der Anstrmung der Geiel mit Windgeschwindigkeiten unter 7,4 m/sec erhlt man Potentiale, die auf eine Geielschwingung von 37 Hz hindeuten. Die Amplitude dieser Potentiale steigt mit dem Anstellwinkel der Geiel und mit der Anstrmgeschwindigkeit.
14.
Das Johnstonsche Organ liefert dem Zentrum also Informationen ber die Strke der Anstrmung. Diese Information ist erst eindeutig, wenn die Biene sie mit Informationen ber den Anstellwinkel der Geiel verknpfen kann.
15.
Ob die von Burkhardt u. G. Schneider (1957) fr Calliphora aufgestellte Hypothese, wonach das Johnstonsche Organ bereits auf die im freien Flug whrend eines Flgelschlags entstehenden Beschleunigungen anspricht, fr die Biene zutrifft, ist noch nicht entschieden. Die unter 7. und 12. aufgezhlten Tatsachen sprechen fr eine solche Mglichkeit. Ein Hren der Biene lie sich bis jetzt mit elektrophysiologischen Methoden nicht nachweisen.
1.
African weaver ants (Oecophylla longinoda) utilize no less than five recruitment systems to draw nestmates from the leaf nests to the remainder of the nest tree and to the foraging areas beyond: (a) recruitment to new food sources, mediated by odor trails produced from the rectal gland, a newly discovered exocrine organ, together with tactile stimuli presented during mouth-opening, antennation, and head-waggling; (b) recruitment to new terrain, entailing odor trails released from the rectal gland and tactile stimulation through antennation: (c) emigration to new sites; (d) short-range recruitment to territorial intruders, during which the terminal abdominal sternite is maximally exposed and dragged for short distances over the ground to release an attractant from the sternal gland, a second newly discovered structure; and (e) long-range recruitment to intruders, mediated by odor trails from the rectal gland and by antennation and intense body jerking.
These systems exist in addition to the elaborate pheromone-mediated alarm communication previously described by Bradshaw et al. (1975). In aggregate, the alarm and recruitment systems of O. longinoda constitute the most complex of such repertories thus far discovered in ants.
2.
Weaver ants recognize new terrain by means of both visual and olfactory cues, with the latter being the more effective. When major workers cannot cross gaps to the terrain by walking, they attempt to make the traverse by building bridges with their bodies. Individuals are attracted to the bridge site visually, but when the bridge is complete, they recruit nestmates to the new terrain with rectal-gland odor trails.
3.
Workers mark newly acquired home range with randomly placed drops of fluid extruded from the rectal vesicle. They distinguish their own domain from that of alien conspecific colonies in part by means of the odor of the anal spots. When a section of terrain is found unmarked, the rate of anal-drop deposition is accelerated, even when adjacent areas are already heavily marked.
4.
The anal substance is a true territorial pheromone: workers respond to alien spots initially with hostility and aversion, then by recruiting nestmates to the vicinity. In laboratory experiments, workers entering an arena simultaneously with workers from alien colonies always gained the initial advantage in the ensuing conflict if they had previously been allowed to mark the arena. When the arena was placed in a spatial position familiar to one colony but possessed a floor previously marked by the second colony, the second colony still won. To our knowledge these results represent the first demonstration of a true territorial pheromone in the social insects.
5.
During foraging the Oecophylla workers move independently of one another and are distributed at random (Poisson distributed) or with slight temporary clumping of no more than two or three workers. Short-range recruitment of intruders causes the ants to shift to a more distinctly clumped pattern, involving as many as ten or more workers, at the same time that long-range recruitment brings more defenders into the vicinity. Together the two forms of response result in a more efficient capture of intruders that are too large to be immobilized by only one or two workers.
6.
The complex recruitment and territorial behavior displayed by O. longinoda is considered to be part of the adaptation of these relatively large ants to a strongly arboreal existence. The similarity of four of the recruitment systems to each other (1 a, b, c, and e above) is interpreted as an example of signal economy in the evolution of social insect communication systems. The parallel evolution has been enhanced by the lack of any strong functional distinction between territorial defense and predation (see Discussion).
6.
Signal ritualization appears to have occurred in at least two contexts: the modification of body thrusting during territorial battles into the jerking signal used in long-range recruitment of nestmates to enemies; and the adoption of anal excrement in the chemical marking of territories.
1.
Hair plates as sense organ on the neck of the honey-bee are the decisive if not the only organ controlling the orientation of the comb and the cells of the comb in the field of gravity. If these plates are lacking the bees cannot even begin to build the comb.
2.
The antennae are superfluous for a correct building of the comb cells (diameter, orientation of the walls of the cells in an angle of 120°. What the measurement for the regular diameter of the comb cells is, is still unknown.
3.
The tips of the antennae have specific sense organs, which are especially apt for controlling the thickness of the walls and for checking the smoothness. The topography of these sense organs and the fine structure of their singular receptors are described.
4.
A theory, which explains the controll of the thickness of the wall from one side only with the help of these sense organs, is developed with reference to the elastic qualities of the cell walls and the behaviour of the building bees. Since the temperature and the selfproduced building material remain constant, a dynamic local displacement of the cell walls by the planing of the mandibles can be measured by the ends of the antennae and correlated with the thickness of the wall.
1.
Durch aktive gerichte Antennenbewegung bringen die Bienen ihre Chemorezeptoren in direkten Kontakt mit dem duftenden Untergrund und vollziehen damit physiologisch eine Kontakt-Chemorezeption.
2.
Diese Kontakt-Chemorezeption schafft die physiologische Grundlage zu einer przisen topochemischen Orientierung. Sie zeichnet sich durch folgende Leistungen aus:
Normale Bienen:
a).
Die Tiere lernen eine Duftorgel qualitativ-sukzessiv nach ihren einzelnen, rumlich getrennten Duftkomponenten in richtiger Reihenfolge aufzulsen (Abb. 3).
b).
Zwei verschiedene, rumlich nahe beieinander liegende Duftkomponenten werden qualitativ-simultan aufgelst. Damit ist ein neuer Nachweis der Osmotropotaxis mit Hilfe der Kontakt-Chemorezeption erbracht (vgl. Martin 1964) (Abb. 22).
Partiell antennenamputierte Bienen:
c).
Nach partieller Antennenamputation geht das rumlich qualitativsukzessive Auflsungsvermgen vollkommen verloren (Abb. 4 und 8).
d).
Das rumlich qualitativ-simultane Auflsungsvermgen erfhrt bei solchen amputierten Bienen einen erheblichen Leistungsrckgang (Abb. 22).
3.
Zwingt man die Bienen beim Rckweg vom Ziel, die Duftorgel in umgekehrter Reihenfolge zu durchlaufen, dann sind die Ergebnisse etwa um 20% schlechter als ohne Gegendressur (wenn der Rckweg keine Duftmarken bietet).
4.
Die Kontakt-Chemorezeption leistet gleichviel in einer Duftorgel, die eine hngende oder eine stehende Blte als Vorbild nimmt.
5.
Der Lern Vorgang zur rumlich qualitativ-sukzessiven Auflsung von Duftmarken in der Duftorgel ist mit kinsthetischer Orientierungsleistung verknpft.
6.
Normale Bienen knnen mit ihren Antennen verschieden strukturierte Oberflchen unterscheiden. Die Dressur wird jedoch uerst erschwert, wenn das gebotene mechanische Muster nicht auch die erwarteten Duftmarken bietet — wie das im normalen Lebensraum der Bienen stets der Fall ist.
7.
Nach partieller Antennenamputation — es gengt bereits die Amputation eines einzigen Gliedes — werden die verschiedenen Oberflchenstrukturen nicht mehr unterschieden.
8.
Bei Duft-Struktur-Konkurrenzversuchen sticht die olfaktorische Information eindeutig die mechano-rezeptorische aus. Sogar spontan gebotene Duftqualitten ben noch etwa die gleiche Attraktivitt aus wie eine in mehreren Tagen erlernte Oberflchenstruktur.
Honeybees fixed in small tubes scan an object within the range of the antennae by touching it briefly and frequently. In
our experiments the animals were able to scan an object for several minutes with the antennae. After moving the object out
of the range of the antennae, the animals showed antennal movements for several minutes that were correlated with the position
of the removed object. These changes of antennal movements are called “behavioural plasticity” and are interpreted as a form
of motor learning. Bees showed behavioural plasticity only for objects with relatively large surfaces. Plasticity was more
pronounced in bees whose compound eyes were occluded. Behavioural plasticity was related to the duration of object presentation.
Repeated presentations of the object increased the degree of plasticity. After presentation durations of 30 min the animals
showed a significant increase of antennal positions related to the surface of the object and avoidance of areas corresponding
to the edges. Behavioural plasticity was compared with reward-dependent learning by conditioning bees to objects. The results
of motor learning and reward-dependent conditioning suggest that bees have tactile spatial memory.
The convergence of primary sensory neurons of the antennae, higher order visual interneurons, and antennal motoneurons was analysed with neuroanatomical techniques in the honeybee, Apis mellifera. The different modalities evoke specific antennal responses in this insect. Three different fluorescent dyes were applied successively in the same preparation in order to visualise the various fiber projections from the antennae and the lobula in the brain of the honeybee. Three neuropile areas where sensory fibers of the antennae overlap with visual projection neurons from the lobula were found. Within the posterior-median protocerebrum the antennal tract T6-1 comes in close vicinity to the lobula tract LoT-9 and to some other lobula fibers that cannot be assigned to a special tract. Antennal T6-3 fibers overlap with lobula LoT-7 neurons within the posterior protocerebrum more laterally. Antennal T5 fibers arborise in the dorsal lobe and show common projection sites with lobula LoT-3 neurons. The multimodal convergence in the three common neuropiles demonstrates that these areas are important centers for multimodal information processing between sensory, motor, and descending neurons in insects.
This paper describes the morphology and location of the cerebral motoneurons that control the movement of the antennae in the honeybee. The position of each antenna is controlled by two muscle systems; the basal segment (scape) is moved by four muscles within the head capsule, and two muscles within the scape control the distal segments (flagellum) of the antenna. The motor system of the scape is controlled by nine motoneurons, and that of the flagellum by six motoneurons. All of these motoneurons share the dorsal lobe as a common projection area where their dendritic fields overlap extensively. These motoneurons do not have contralateral projections. The cell bodies of the antennal motoneurons are located in the soma layer lateral to the dorsal lobe. The somata for each muscle system are arranged in three clusters; two clusters are located in a region of the cortex dorsal to the dorsal lobe and one cluster is located in the cortex ventral to the dorsal lobe. In the cortex dorsal to the dorsal lobe, one cluster of each muscle system shares the same region. Altogether five groups of cell bodies can be distinguished. Double labeling of the motoneurons and presumptive mechanosensory primary antennal afferents with fluorescent dyes has shown that there is an extensive overlap of axonal projections of antennal mechanosensory afferents with dendritic fields of antennal motoneurons.
Antennal motor activity of the honeybee was used to test the effects of sucrose stimuli and of serotonin and octopamine microinjections into the brain. The antennal scanning behavior was analyzed in behavioral experiments. Activity of an antennal muscle, the "fast pedicellus flexor muscle" which dominates scanning behavior, was used as a physiological measure of modulatory effects. A single sucrose stimulus applied to both the antenna and the proboscis leads to significant increases of the frequency of antennal scanning compared to those of untreated controls and animals stimulated with water. A single sucrose stimulus applied only to the antenna or the proboscis has no significant behavioral effects. Injection of small volumes (approximately 500 pl) of serotonin (5HT) or octopamine (OA) at concentrations of 10(-5) M into the dorsal lobe, the sensory motor center of the antenna, leads to functionally antagonistic behavioral effects. While 5HT injection significantly reduces the antennal scanning frequency, OA significantly enhances it. The degree of behavioral modulation is significantly correlated with the activity of the animals. In animals which display low scanning activity, OA injection has an enhancing effect, while 5HT has no effect. In contrast, 5HT injection, but not OA injection, produces a behavioral effect in animals with high scanning activity. Behavioral changes and changes of activity of the fast pedicellus flexor muscle are closely correlated. Significant, functionally antagonistic effects of 5HT and OA on muscle activity were found after injections of the compounds into the dorsal lobe. 5HT leads to a reduction of the muscle potential frequency starting immediately after injection and lasting at least 15 min. OA injection results in an increase of frequency, which has its maximum 5 min after injection. The experiments demonstrate that sucrose, the reward stimulus during associative learning in the bee, also modulates motor activity under nonassociative conditions. The similar effects of sucrose stimulation and OA injection are consistent with the hypothesis that OA mediates the effects of sucrose stimuli.
Wahmehmung und Regelung der Flugeigengeschwindigkeit bei Ap is mellific a L. Zeitschrift fiir vergleichende P hys iologie 42
- H Heran
Heran, H. (1959). Wahmehmung und Regelung der Flugeigengeschwindigkeit bei
Ap is mellific a L. Zeitschrift fiir vergleichende P hys iologie 42, 103 -l 63.