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Does Dysdera crocata (Araneae Dysderidae) prefer woodlice as prey?
Abstract
Three different types of prey-preference tests were carried out using Dysdera crocata, a spider frequently described as a specialist predator of woodlice. None of these tests provided evidence that Dysdera crocata prefers woodlice over a variety of insect prey (house flies, beetle larvae, mirid bugs, moths and crickets). We also ran prey preference tests with two species of woodlice that differ in their behavioural and chemical defences, and there was no evidence of preference for either of these species over the other. The broader question of whether D. crocata is a specialized predator in any respect is discussed.
... Generalist predators rarely feed on woodlice (Gorvett 1956), but such cases are known for hedgehogs (Shilova-Krassova 1952), shrews (Perneta 1976), moles (Godfrey and Crowcroft 1960), frogs, toads, lizards, birds, and some predatory arthropods (Sunderland and Sutton 1980;Bureš and Weidinger 2003). On the other hand, ants of the tropical genus Leptogenys (Dejean 1997; Dejean and Evraerts 1997), spiders of the Palaearctic genus Dysdera (Pollard et al. 1995;Rezáč and Pekár 2007;Pekár and Toft 2015) and toad bugs Nerthra macrothorax possess adaptation for the effective capture of armored woodlice and detoxication mechanisms alleviating feeding on woodlice (Sunderland and Sutton 1980;Pekár et al. 2016). Approximately 15 other spider species from ten families are suggested to be specialized woodlice predators (Bristowe 1941(Bristowe , 1958Uhlenhaut 2001;Rezáč et al. 2008). ...
Terrestrial crustaceans are represented by approximately 4,900 species from six main lineages. The diversity of terrestrial taxa ranges from a few genera in Cladocera and Ostracoda to about a third of the known species in Isopoda. Crustaceans are among the smallest as well as the largest terrestrial arthropods. Tiny microcrustaceans (Branchiopoda, Ostracoda, Copepoda) are always associated with water films, while adult stages of macrocrustaceans (Isopoda, Amphipoda, Decapoda) spend most of their lives in terrestrial habitats, being independent of liquid water. Various adaptations in morphology, physiology, reproduction, and behavior allow them to thrive in virtually all geographic areas, including extremely arid habitats. The most derived terrestrial crustaceans have acquired highly developed visual and olfactory systems. The density of soil copepods is sometimes comparable to that of mites and springtails, while the total biomass of decapods on tropical islands can exceed that of mammals in tropical rainforests. During migrations, land crabs create record-breaking aggregations and biomass flows for terrestrial invertebrates. The ecological role of terrestrial microcrustaceans remains poorly studied, while omnivorous macrocrustaceans are important litter transformers and soil bioturbators, occasionally occupying the position of the top predators. Notably, crustaceans are the only group among terrestrial saprotrophic animals widely used by humans as food. Despite the great diversity and ecological impact, terrestrial crustaceans, except for woodlice, are often neglected by terrestrial ecologists. This review aims to narrow this gap discussing the diversity, abundance, adaptations to terrestrial lifestyle, trophic relationships and ecological functions, as well as the main methods used for sampling terrestrial crustaceans.
... Most euryphagous generalist spider species avoid taking woodlice (Bristowe, 1941) and they show low performance when restricted to a diet of woodlice . Species of the genus Dysdera (Dysderidae), however, have long been known for their acceptance and even preference for this prey (Bristowe, 1941;Cooke, 1965;Pollard et al., 1995;Ř ezáč and Pekár, 2007). On top of this, Ř ezáč et al. (2008) could relate morphological peculiarities, e.g. ...
Spiders of the genus Dysdera are peculiar for their preying on terrestrial isopods though the preference for this prey type varies between species. We tested prey acceptance of two isopod and two non-isopod prey in 8 species endemic to the Canary Islands, and analyzed growth and metabolic parameters (growth efficiency; dry mass, lipid and N extraction efficiency; lipid:protein consumption ratio) of 6 of these species when fed either house flies (Musca domestica) or isopods (Porcellio scaber) in the laboratory. The species represented four morphological types (unmodified chelicerae, slightly elongated chelicerae, concave chelicerae, flattened fang), supposedly reflecting different specializations to isopod prey. The results showed reduced relative acceptance of non-isopod and increased acceptance of isopod prey in species groups with specialised morphologies compared to the unmodified species group. All species had similar or lower growth and growth efficiency when feeding on isopods than on flies. Extraction efficiency of dry mass and lipid were higher for flies than for isopods, while extraction efficiency of protein was higher for isopods than for flies. All species also utilized isopod protein equally well, but protein utilization of flies was lower in the presumed specialist compared to generalist species, indicating a possible metabolic trade-off from isopod specialisation. Thus, morphological adaptations were associated with increased behavioural preferences for isopods and reduced metabolic ability to handle ‘generalist’ prey.
... According to Sunderland et al. [55], isopods might rarely be attacked by predators, and most such attacks are directed towards juveniles. However, some predators are believed to be isopod specialists, such as the woodlouse spider Dysdera crocata (but see [56]). The preferred temperatures of D. crocata [57] appear to closely match the preferred temperatures of its potential prey, the sympatric woodlouse P. laevis [58]. ...
Environmental temperatures and oxygen availability are important for the balance between oxygen supply and demand. Terrestrial organisms are generally perceived to be less limited by access to oxygen than their aquatic counterparts. Nevertheless, even terrestrial environments can be deficient in oxygen, especially for organisms occurring in soil, litter, wood, rotten fruit or at high elevations. While isopods are the best adapted to a terrestrial lifestyle among crustaceans, many species, including woodlice, occupy environmental gradients of temperature and oxygen. To investigate whether mismatches between oxygen supply and demand can result in a loss of performance in a terrestrial organism, we studied the effects of atmospheric oxygen concentration on the thermal performance of the common rough woodlouse (Porcellio scaber). We compared the thermal preference, thermal sensitivity of running speed, and tolerance to extreme temperatures of woodlice exposed to one of two oxygen concentrations (21% - normoxia, 7% - hypoxia). Under hypoxia, P. scaber preferred microhabitats with temperatures that were on average 3°C lower than those preferred under normoxia. The running speed tended to reach its maximum at a lower temperature under hypoxia than under normoxia (25.13°C vs 28.87°C, respectively, although p was equal to 0.09), and normoxic woodlice ran approximately 1.5-fold faster than hypoxic woodlice at the point of maximum speed. Heat tolerance was significantly lower under hypoxia (38.9°C) than under normoxia (40.7°C), but there was no difference in cold tolerance (5.81°C under normoxia and 5.44°C under hypoxia). Overall, our results indicate that environmental gradients of temperature and oxygen may shape the physiological performance of terrestrial ectotherms, likely via their effects on the balance between oxygen supply and demand, which may have fitness consequences for these organisms in nature.
... Some species are considered to be prey specialists with isopods as their focal prey (Bristowe, 1941;Cooke, 1965;Řezáč & Pekár, 2007). However, no known Dysdera species is a strict specialist in the sense of accepting only isopods, and some species do not even prefer woodlice over other prey types (Pollard et al., 1995;Rezáč et al., 2008). Common to generalist spiders, they accept a wide range of prey types (Pekár & Toft, 2015). ...
The spider genus Dysdera is considered to comprise specialist isopod feeders, although the degree of specialization varies between species, depending on morphological (shape of chelicerae), behavioural (attack tactics) and metabolic (food quality of prey) adaptations. Dysdera has radiated extensively in the Canary Islands (currently 47 endemic species are described) and codistributed species have different cheliceral shapes and body sizes indicating different feeding niches. In the present study, we investigate the existence of metabolic adaptations to feeding on isopods by three endemic species (Dysdera insulana Simon, Dysdera macra Simon and Dysdera verneaui Simon) from Tenerife. We hypothesize that there is enhanced extraction efficiency of fundamental macronutrients from isopods compared with control prey in species with special morphological and behavioural adaptations for this prey type. We measure quantitatively spider growth, dry mass consumption, lipid and nitrogen consumption, and calculate growth efficiency and efficiency of utilization of dry mass, lipid and nitrogen. The results show that all three species are able to utilize both prey types, indicating that none of them are strict isopod specialist. Dysdera insulana shows enhanced growth efficiency and D. macra shows enhanced nitrogen extraction efficiency compared with D. verneaui when feeding on Porcellio rather than on Musca. Both traits indicate likely adaptations for the utilization of isopods. Spider species, sex and prey type all affect lipid and nitrogen extraction efficiencies, indicating that spiders do not simply extract nutrients in the proportions available. The results support the hypothesis that adaptations for enhanced digestion of focal prey evolve in species that already have adaptations for enhanced capture success.
... Dysdera crocata is a cosmopolitan woodlice specialist (Cooke, 1967). It feeds mainly on woodlice but also takes alternative prey (Pollard et al., 1995). It is a nocturnal hunter (Budiš, 2008) occurring in epigeon, near to human buildings where woodlice are common (Řezáč et al., 2008). ...
1. Predators select a prey according to its energetic and nutritional composition. Generalist predators avoid, whereas specialists often specialise on well‐defended prey. The aim of this study was to find the suitability of woodlice prey for generalist and specialist predators by comparing their handling efficiency.
2. Laboratory experiments were performed in which specialist and generalist predators were reared on monotypic diets comprising one or other of two woodlice species that differ in their defensive strategies: rollers ( Armadillidium ) and clingers ( Porcellio ). A control group was reared on a mixture of arthropods (excluding woodlice). Three spider predators were used that differ in their adaptations to deal with woodlice prey: a woodlice specialist, Dysdera crocata ; an oligophagous generalist, Pholcus phalangioides , that also captures woodlice; and a euryphagous generalist, Tegenaria domestica , that does not feed on woodlice. The frequency of capture was recorded and various fitness parameters were measured, namely survival, growth rate, and ontogenetic development.
3. It was found that the specialist, D. crocata , performed best on the Porcellio diet, and similarly well on Armadillidium and mixed diets. The two generalists, P. phalangioides and T. domestica , had poor performance on both woodlice diets but performed well on the mixed diet.
4. The results show that woodlice are unsuitable prey for both oligophagous and euryphagous generalist predators.
... In the present study, we examine the relationship between short-term and long-term predator cues and alternating turn behavior in P. laevis and A. vulgare. Oniscids are subject to predation from diverse animals, including ants (Deslippe et al., 1995), spiders (Barmeyer, 1975;Nyffleler and Benz, 1981;Pollard et al., 1995), frogs (Lehman, 1978), toads (Linzey et al., 1998) 1986), birds (Kawaji and Shiraishi, 1980), and mammals (Grainger and Farley, 1978). ...
The Dysderidae fauna of the Maltese Islands is reviewed. Dysdera kollari Doblika, 1853, D. lagrecai Alicata, 1964 and Harpactea sicula Alicata, 1966 are recorded for the first time from the Maltese archipelago, and the latter two species are recorded for the first time outside Italian territories. Harpactea corticalis (Simon, 1882) is removed from the Maltese dysderid fauna list. Distributional notes for all four species present in the Maltese Islands are provided, with the first records of Dysderidae from Comino.
The genus Dysdera Latreille, 1804, a species-rich group of spiders that includes specialised predators of woodlice, contains several complexes of morphologically similar sibling species. Here we investigate species limits in the D. erythrina (Walckenaer, 1802) complex by integrating phenotypic, cytogenetic and molecular data, and use this information to gain further knowledge on its origin and evolution. We describe 16 new species and redescribe four poorly known species belonging to this clade. The distribution of most of the species in the complex is limited to southern France and the north-eastern Iberian Peninsula. The species studied do not show any obvious differences in habitat preference, and some of them even occur sympatrically at certain sites. They probably feed on the same type of prey as they readily capture woodlice. On the other hand, they differ in body size, mouthparts shape, sculpturing of carapace, morphology of the copulatory organs, karyotype and DNA sequences. Experimental interspecific mating showed a partial precopulatory behavioural barrier between D. erythrina and D. cechica, sp. nov. Our data suggest that karyotype evolution of the complex included chromosome fusions and fissions as well as translocations (between autosomes as well as autosomes and sex chromosomes). We hypothesise that chromosome rearrangements generating reproductive incompatibility played a primary role in speciation within Dysdera complexes. Dysdera spiders are poor dispersers, and their original distribution areas (forested areas in the Mediterranean) were repeatedly fragmented during Quarternary climatic oscillations, facilitating integration of chromosome rearrangements into karyotypes by genetic drift. Sympatric occurrence of closely related species may have been promoted by prey segregation as suggested by differentiation in body size in co-occurring species. The following new species are described: D. catalonica, sp. nov., D. cechica, D. dolanskyi, sp. nov., D. fabrorum, sp. nov., D. garrafensis, sp. nov., D. graia, sp. nov., D. kropfi, sp. nov., D. minairo, sp. nov., D. portsensis, sp. nov., D. pradesensis, sp. nov., D. pyrenaica, sp. nov., D. quindecima, sp. nov., D. septima, sp. nov., D. stahlavskyi, sp. nov., D. tredecima, sp. nov. and D. undecima, sp. nov.
Terrestrial isopods have developed a lightweight exoskeleton to the demands of different predation possibilities, for example fast escaping behavior (runner) to rolling into a ball to withstand external forces. However, detailed mechanical investigations onto them are not available yet. Therefore, the aim of this study is the characterization of the mechanical properties of different terrestrial isopods to create new biomimetic impact materials. Pill bugs and woodlice show a gradual change of the mechanical properties from the outer to the innermost part of the cuticle, which was measured by nanoindentation. These tests showed a young's modulus of 10-30 GPa and a hardness from 0.1 GPa to more than 2.0 GPa in Porcellio scaber and a higher hardness in Armadillidium vulgare. These results will serve as basis for further biomimetic investigations.
Predators appear to be less frequently specialised (i.e. adapted to restricted diet) on their prey than herbivores, parasites or parasitoids. Here, we critically evaluate contemporary evolutionary hypotheses that might be used to explain the evolution of specialised foraging in predators. We propose a unifying concept within which we define four types of trophic categories using ecological (diet breadth) and evolutionary (degree of adaptations) contexts. We use data on spiders (Araneae), the most diversified order of terrestrial predators, to assess applicability of frameworks and evolutionary concepts related to trophic specialisation. The majority of spider species are euryphagous but a few have a restricted prey range, i.e. they are stenophagous. We provide a detailed overview of specialisation on different prey types, namely spiders, crustaceans, moths, dipterans, ants, and termites. We also review the available evidence for trophic adaptations, classified into four categories: behavioural, morphological, venomic and metabolic. Finally, we discuss the ecological and evolutionary implications of trophic specialisation and propose avenues for future research.
Feeding experiments were performed with seven species of non-webbuilding spiders and a variety of prey taxa. Some species were generally polyphagous whereas other spiders restricted their prey to a few groups. At one end of the spectrum of prey specialization the thomisid Misumena vatia is limited to a few taxa of possible prey (Table 1). The literature of prey records of non-webbuilding spiders is reviewed (Table 2) with special emphasis on oligophagous or monophagous spiders. Monophagous spiders are generally rare and have specialized on only a few prey taxa: social insects (ants, bees, termites) and spiders.
(1) Predation by arthropods on woodlice in dune grassland at Sprun Head, Yorkshire, was studied in 1971 and 1972 using rabbit antisera specific against Isopoda, Philoscia muscorum (Scopoli) and Armadillidium vulgare (Latreille). (2) Field data on percentage antigen positive reactions and predator densities were used with laboratory data on feeding rates and detection period of antigens in predator guts to calculate predation rates for each species. (3) 3268 predators belonging to eighty-one species were tested. Forty-five species had fed on woodlice in the field. (4) Between April and November a minimum of 437 woodlice per m2 were taken by predators and at least 85% of these were immature woodlice. Predation on the different species of woodlice was approximately proportional to the numerical abundance of each species on the study site at the time. 8.5% of predators had eaten a meal consisting of more than one species of woodlouse. (5) Lithobius forficatus (L.) accounted for 42% of the total number of woodlice killed, Coleoptera for 30% and the rest were eaten by Araneae and Opiliones. Predation by the earwig, Forficula auricularia L., was negligible. (6) Most predators would feed on dead woodlice (facultative scavengers) but eight species that were unable to kill woodlice fed to a significant extent on dead woodlice in the field (obligate scavengers). Lithobius forficatus preferred dead woodlice to living woodlice in the laboratory but the facultative scavengers probably ate few dead woodlice in the field because woodlouse corpses were rapidly removed by obligate scavengers. (7) It was estimated that predation could have reduced the pre-breeding population of woodlice by a minimum of 24%. The percentage of juvenile mortality that was due to predation was estimated to be between 11% (predators and prey uniformly distributed) and 51% (all predators feeding in areas of prey aggregation).
The genus Dysdera comprises approximately eighty species, of which the great majority are Western European or Mediterranean in distribution. This paper is one of a series resulting from an investigation into some of the basic problems of Dysdera taxonomy (see Cooke 1965a for a general account) and summarises our present knowledge of the biology of the group. The main topics discussed are the prey, predators and parasites of Dysdera, and various aspects of the sexual biology. Under the latter heading are included sections on courtship, copulation, seasonal activity and egg laying. An account is also given of interspecific matings, which although never occurring in wild populations, may occasionally be induced in laboratory-reared individuals. The eggs resulting from such mating are infertile. /// Род Dysdera включает около 80 видов, большинство из которых распространены в западной Европе и на побережье Средиземного моря. Настоящая статья содержит данные побиологии Dysdera. полученные при таксономических исследованиях представителей зтой группы (основная статья - Сооке, 1965). В статье приводятся данные об объектах питания и естественных врагах пауков, обсуждаются различные аспекты биологии размножения Dysdera, а именно, брачные игры, особенности спаривания, сезонная активность и откладка яиц. Уделенов нимание вопросам межвидового скрещивания, которое, хотя и не встречается в природе, но может наблюдаться в пауков, содержащихся в лабораторных условиях. Яйца, отложенные в резулвтате такого спаривания нежизнеспособны.
The manner in which Dysdera crocata used its large chelicerae was described. Previous claims that the chelicerae are adaptations enabling the spider to penetrate the dorsal carapace of its prey (woodlice) were not supported.
The predatory behaviour of Chrysilla lauta and Sliersemiglaucus from Sri Lanka, and four species of Natta from Kenya, was studied in the laboratory for the first time. These salticids eat ants, a prey most salticids avoid. These species' specialized behaviour for catching ants is described and compared to their behaviour for catching other insects. Three different types of tests of prey preference were carried out and, in each type, ants were taken in preference to other insects. Preference for ants, and prey-specific predatory behaviour did not depend on prior experience with ants. Results from this study are discussed in relation to recent findings on other ant-eating salticids.
Corythalia canosa from Florida is an unusual salticid because it is known to eat ants. This species' specialized behaviour for catching ants is described in detail for the first time and compared to its behaviour for catching other insects. Pystira orbiculata from Queensland is shown to be another ant-eating salticid, although its behaviour for catching ants seems less specialized than that of C. canosa. Three different types of tests of prey preference were carried out. In each type of test C. canosa and P. orbiculata took ants in preference to other insects. Another species of salticid, Trite planiceps from New Zealand, failed to eat ants in these tests, although T. planiceps often attacked then released the ants. Corythalia canosa's and P. orbiculata's preference for ants, and their prey-specific predatory behaviour for catching ants, are shown not to depend on prior experience with ants.
The lobed tegumental glands would seem to play an important part in adapting woodlice to life on land, but although the problem seems a simple one, it has by no means been easy to determine their function.
Evidence from comparative anatomy and physiology is unhelpful and often puzzling, and inactivating the glands seems to have no effect on normal life.
Evidence from a more direct experimental investigation of a variety of hypotheses suggests that the glands do not perform any of the more obviously possible functions, and that they are not concerned with general defence, secretion of gill fluid, water‐proofing the body‐wall, attachment to the substratum, moulting, lubrication of the skin, reproduction, silk formation, capillary water conduction to the gills, temperature control, humidity reactions, or regulation of water content of the body.
Evidence of various kinds suggests that the function performed by the glands is that of defence, not against predators in general, but against one particular group, namely spiders.
Spiders appear to be potentially the most serious enemies of woodlice; but they find woodlice distasteful and the degree of distastefulness is correlated to a remarkable extent with the degree of development of the lobed glands. There is other evidence that the distastefulness is a property of the lobed gland secretions and not of the body tissues and fluids as a whole.
When a woodlouse is attacked by a spider, its lobed glands secrete precisely as they do when stimulated experimentally, and this is the only evidence ever obtained of secretion occurring under natural conditions.
If the function of the lobed glands is to repel spiders, many of the objections to the general defence hypothesis can be answered, and many other puzzling facts relating either to the glands or to the behaviour of woodlice can be explained.
In this paper, an experiment is described on the assimilation of zinc, cadmium, lead, copper and iron by Dysdera crocata collected from a site in central Bristol. The spiders were fed on woodlice from their own site, and on woodlice from a site contaminated by a smelting works which contained much higher levels of zinc, cadmium and lead than the spiders would have been used to in their normal diet.
Prey capture in Dysdera crocata (Araneae: Dysderidae), a long fanged spi-der A serological study of arthropod predation on woodlice in a dune grassland ecosystem
- Pollard S D Sunderland
- K D L Sutton S
POLLARD S.D. 1986. Prey capture in Dysdera crocata (Araneae: Dysderidae), a long fanged spi-der. New Zealand Journal of Zoology 13: 149-150. SUNDERLAND K.D. & SUTTON S.L. 1980. A serological study of arthropod predation on woodlice in a dune grassland ecosystem. Journal of Animal Ecology 49: 987-1004.