Olfactory search-image use by a mosquito-eating predator

By choosing blood-carrying mosquitoes as prey, Evarcha culicivora, an East African salticid spider, specializes at feeding indirectly on vertebrate blood. It also has an exceptionally complex mate-choice system. An earlier study revealed that search-image use assists E. culicivora in finding prey and mates when restricted to using vision alone. Here we show that search-image use assists E. culicivora in finding prey and mates when restricted to using olfaction alone. After being primed with prey odour or mate odour (control: not primed with odour), spiders were transferred to an olfactometer designed to test ability to find a prey-odour or mate-odour source that was either ‘cryptic’ (i.e. accompanied by a masking odour source, Lantana camara) or ‘conspicuous’ (no L. camara odour). When tested with conspicuous odour, the identity of the priming odour had no significant effect on how many spiders found the odour source. However, when tested with cryptic odour, significantly more spiders found the odour source when primed with congruent odour and significantly fewer spiders found the odour source when primed with incongruent odour.     

Cross‐Modality Effects of Prey Odour During the Intraspecific Interactions of a Mosquito‐Specialist Predator

One of the predictions from evolutionary game theory is that individuals will increase their willingness (i.e. become primed) to escalate aggression when they detect the presence of a limiting resource. Here, we test this prediction in the context of prey odour priming escalation decisions during vision‐based encounters by Evarcha culicivora. This East African jumping spider (Salticidae) feeds indirectly on vertebrate blood by actively choosing blood‐carrying female mosquitoes as preferred prey. Unlike many salticid species, it also expresses pronounced mutual mate choice. As predicted, we show here that, in the presence of odour from their preferred prey, both sexes of E. culicivora escalate during vision‐based same‐sex encounters. This is further evidence that the odour of blood‐carrying mosquitoes is salient to this salticid. For both sexes of E. culicivora, this particular prey may be a resource that matters in the context of intrasexual selection.     

Prey Luring Coloration of A Nocturnal Semi‐Aquatic Predator

Body coloration serves a variety of purposes in animals. Diurnal and nocturnal predators such as spiders may use their body coloration to lure prey. We predicted here that the white patches on the forelegs on females of the nocturnal semi‐aquatic spider Dolomedes raptor lure prey, explaining why they are primarily displayed when the spider forages along the water edge. To test our prediction, we developed a color vision model assessing whether the patches are visible to pygmy grasshoppers, the spider's primary prey. We conducted a field experiment using cardboard dummies that resemble D. raptor in size, shape, and color, but with half of them lacking leg patches, and we staged interactions between pygmy grasshoppers and D. raptor with and without leg patches in a greenhouse. We found the white patches to be visible to grasshoppers. The dummies with white patches attracted more grasshopper prey than the dummies without the patches. Moreover, grasshoppers were more attracted to spiders when their white patches were present. Our results supported the hypothesis that the white patches of D. raptor lure prey. Our findings, nevertheless, could not be explained as the spider's body coloration acting as a sensory trap but it should not be ruled out. More studies on a wider range of predators and prey will give more meaningful insights into the co‐evolution of predatory lures and prey sensory modalities.     

The Functioning of Species-Specific Olfactory Pheromones in the Biology of a Mosquito-Eating Jumping Spider from East Africa

Having unique, complex eyes and vision based on exceptional spatial acuity, salticid spiders are known for their vision-based predatory and mating strategies. Yet Evarcha culicivora, the salticid we consider here, is known for predatory and mating strategies based strongly on the interplay of vision and olfaction. This unusual East African species feeds indirectly on vertebrate blood by choosing blood-carrying female mosquitoes as preferred prey, which it can identify by sight and by smell. Moreover, E. culicivora’s mating strategy is unusual because, unlike the prevailing general pattern among spiders, where males are more active in courtship and females are more active in mate choice, both roles are characteristic of both sexes of E. culicivora. There is also an unusual relationship between diet and mating in this species, with blood meals making both sexes more attractive as potential mates. However, findings from the present study demonstrate that, regardless of source-spider diet and even when restricted to using chemoreception in the absence of seeing another spider, both sexes can discriminate between opposite-sex conspecifics and opposite-sex heterospecifics. Yet there is no evidence that diet (blood versus no blood) influences the attractiveness of opposite-sex heterospecific individuals to E. culicivora. Evidence that the odor of opposite-sex conspecifics is salient to E. culicivora comes from three different experimental designs (retention testing, choice testing and courtship-initiation testing). The effective odor source can be either the presence of the spider or the presence of the spider’s draglines alone.     

Adaptive Timing as a Component of a Mosquito-Eating predator’s Specialization Profile

Evarcha culicivora, a salticid spider from East Africa, is a mosquito specialist which feeds indirectly on vertebrate blood by actively choosing blood-carrying mosquitoes as preferred prey and by actively choosing Anopheles as preferred mosquitoes. Here we investigate for the first time whether specialization by this predator is also expressed in the timing of its predatory activity. With data from field sampling and from systematically observing E. culicivora under semi-field conditions, we show that instances of predation tend to be most common in the early morning hours, this being when especially many night-feeding anthropophilic anopheline mosquitoes are resting while digesting blood acquired during the night. Experimental data show that E. culicivora is significantly more responsive to prey in the morning than in the afternoon, where ‘responsive’ includes being significantly more inclined to eat living prey, choose the preferred prey, approach a source of prey odor in the absence of visible prey and approach lures made from dead prey that can be seen but not touched or smelled. We found no significant diel pattern in E. culicivora’s inclination to mate and, although mate, plant and human odors are all known to be salient to E. culicivora, we found no significant diel pattern in response to any of these odors. Our findings suggest that E. culicivora’s innate pattern of predatory activity is adaptively adjusted in a way that facilitates predation on its preferred prey.     

Female‐targeted attractant containing pear ester for Synanthedon myopaeformis

When testing pear ester (ethyl‐2,4‐decadienoate) + acetic acid (PEAA) lures to catch codling moths, Cydia pomonella (L.) (Lepidoptera: Tortricidae), in Hungary, significant catches of the apple clearwing moth, Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae), were also recorded. This sesiid is one of the most important pests of apple in Europe. Pear ester plus acetic acid lures were attractive to S. myopaeformis no matter whether the two compounds were provided in separate dispensers or mixed together in a single dispenser, and a large percentage (40–80%) of the clearwing moths caught were females. In all cases, traps baited with binary combinations of PEAA caught far more than traps baited with either of the compounds presented alone. Traps with PEAA lures in some tests caught (females and males together) up to ca. 20% of the catch in traps baited with the synthetic apple clearwing moth sex attractant (all males). Consequently, the PEAA lure shows potential for future practical applications as a female‐targeted lure. To our knowledge, this is the first report of attractiveness of a lure containing pear ester for non‐tortricid Lepidoptera. Our finding suggests that the compound may be exploited as a host location stimulus by a wider array of insects than was indicated previously.     

Complex display behaviour of Evarcha culicivora,an East African mosquito‐eating jumping spider

Abstract

Evarcha culicivora, an East African jumping spider (Salticidae), is an unusual predator because it feeds indirectly on vertebrate blood by choosing blood‐carrying mosquitoes as preferred prey. It also associates with particular plant species, Lantana camara and Ricinus communis. Here we document this species’ exceptionally complex display repertoire. In common with many other salticids, E. culicivora exhibits pronounced courtship versatility, with males using different tactics depending on the female's location and state of maturity. However, in contrast to most other salticids that have been studied, the males and the females of E. culicivora are both active at initiating and sustaining courtship, and both sexes are cannibalistic. Contrary to the emphasis in the literature on female spiders eating males, females of E. culicivora run a higher risk of being killed by males than vice versa during courtship. E. culicivora males also differ from other salticids that have been studied by adopting pronounced copulatory courtship. Male‐female interactions of E. culicivora are especially complex when encounters are in the foliage of L. camara and R. communis.     

Indirect cues in selecting a hunting site in a sit‐and‐wait predator

Sit‐and‐wait predators use relatively simple rules for their decisions to choose and leave a patch, such as using the direct presence of prey to select a hunting site. However, the direct presence of prey can only be used when there is a highly visited patch in the proximity of the predator. Therefore, it is plausible that sit‐and‐wait predators also exploit indirect cues of prey presence and, consequently, use associative learning to select a hunting site. The present study tests for the role of associative learning in a sit‐and‐wait predator species for which the ecology is well understood: Misumena vatia Clerck crab spiders. An ecologically relevant scenario is used by selecting flower colour as the conditioned stimulus and prey presence as the unconditioned stimulus. The results provide no evidence that M. vatia crab spiders use the association between flower colour and food presence for selecting a hunting site. After a training phase of being exposed to a colourful artificial flower highly visited by bees, spiders select a hunting site independently of its colour during the testing phase. Investigations of similar scope and ecological relevance are required with other sit‐and‐wait predators to identify the conditions promoting the use of associative learning for foraging site selection when animals face an unpredictable food supply.     

Male and Female Mate-Choice Decisions by Evarcha culicivora, An East African Jumping Spider

There has been a considerable recent interest in the criteria by which animals choose mates and in the extent to which mating systems tend to be based on mutual mate choice. In this study, we consider Evarcha culicivora, a salticid spider from East Africa. This species has some unusual characteristics, including active display by females as well as males, males that kill females more frequently than females kill males and wide intrasexual variation in body size. For females, larger males are especially dangerous. Here, we demonstrate, using two experimental designs (live‐mate choice and mount choice), that virgin males, virgin females and previously mated males prefer larger opposite‐sex individuals as potential mates, but mated females prefer smaller, safer males as potential mates.     

Monitoring codling moth (Lepidoptera: Tortricidae) with a four‐component volatile blend compared to a sex pheromone‐based blend

Monitoring adult codling moth, Cydia pomonella (L.), is a crucial component in implementing effective integrated management programmes in apple, Malus domestica Borkhausen. Use of sex pheromone lures to track male populations has been the traditional approach, but their use in orchards treated with sex pheromone for mating disruption (MD) has been problematic. Development of kairomone and kairomone–pheromone combination lures has allowed the catch of female moths and has benefited several aspects of codling moth management through improved spray timings and action thresholds. Recently, a new four‐component volatile blend (4‐K) comprised of pear ester, (E,Z)‐2,4‐ethyl decadienoate (PE), (E)‐11 4,8‐dimethyl‐1,3,7‐nonatriene, all isomers of pyranoid linalool oxide and acetic acid (AA) has been characterized that has increased female moth catch threefold versus any previous blend. Field trapping studies were conducted to compare moth catches in traps baited with 4‐K versus the use of sex pheromone, (E,E)‐8,10‐dodecadien‐1‐ol (PH) in combination with PE and AA. Trials were conducted in orchards left either untreated, or treated with PH or PH + PE. Traps baited with 4‐K and 4‐K + PH lures caught significantly more females than traps baited with PH + PE + AA lures. Traps baited with 4‐K + PH lures caught significantly more total moths than traps baited with PH + PE + AA lures in all three orchards. Adding a PH lure to traps with the 4‐K lure did not affect female catch, but significantly increased male and total moth catches. These studies demonstrate that codling moth can be trapped effectively in apple under MD without the use of sex pheromone lures. The significant increase in female codling moth catch with the 4‐K lure suggests that efforts to improve spray timings and action threshold determinations as well as mass trapping might be enhanced with this new lure.     

Odour‐mediated response to plants by evarcha culicivora,a blood‐feeding jumping spider from East Africa

Abstract

Evarcha culicivora Wesolowska & Jackson, a salticid from the Lake Victoria region of East Africa, is known to associate with Lantana camara L. (family Verbenaceae) and Ricinus communis L. (family Euphorbiaceae), two plant species that are common in the same habitat. E. culicivora is an unusual salticid because, by choosing blood‐carrying mosquitoes as preferred prey, it feeds indirectly on vertebrate blood, and E. culicivora apparently also feeds on nectar taken from L. camara and R. communis. The experimental findings reported here show that the odour of these two plants is salient to E. culicivora. A Y‐shaped olfactometer was used in the experiments, with plant odour on one side and the other side a control (no odour). Juveniles, adult males and adult females chose the odour of L. camara and R. communis more often than the control.     

MHC‐disassortative mate choice and inbreeding avoidance in a solitary primate

Sexual selection theory suggests that choice for partners carrying dissimilar genes at the major histocompatibility complex (MHC) may play a role in maintaining genetic variation in animal populations by limiting inbreeding or improving the immunity of future offspring. However, it is often difficult to establish whether the observed MHC dissimilarity among mates drives mate choice or represents a by‐product of inbreeding avoidance based on MHC‐independent cues. Here, we used 454‐sequencing and a 10‐year study of wild grey mouse lemurs (Microcebus murinus), small, solitary primates from western Madagascar, to compare the relative importance on the mate choice of two MHC class II genes, DRB and DQB, that are equally variable but display contrasting patterns of selection at the molecular level, with DRB under stronger diversifying selection. We further assessed the effect of the genetic relatedness and of the spatial distance among candidate mates on the detection of MHC‐dependent mate choice. Our results reveal inbreeding avoidance, along with disassortative mate choice at DRB, but not at DQB. DRB‐disassortative mate choice remains detectable after excluding all related dyads (characterized by a relatedness coefficient r > 0), but varies slightly with the spatial distance among candidate mates. These findings suggest that the observed deviations from random mate choice at MHC are driven by functionally important MHC genes (like DRB) rather than passively resulting from inbreeding avoidance and further emphasize the need for taking into account the spatial and genetic structure of the population in correlative tests of MHC‐dependent mate choice.     

Crab spiders (Thomisidae) attract insect flower‐visitors without UV signalling

1. Crab spiders (Thomisidae) indirectly affect insect flower‐visitor and flowering plant interactions by consuming and altering the behaviour of insects. 2. Although one expects insect flower‐visitors to avoid crab spiders actively, some crab spider species are known to attract flower‐visitors. Crab spiders may use UV signalling to lure potential prey to the flowers they occupy. 3. In the present study, a field experiment was conducted to examine the effects of crab spiders occupying three prairie plant species for the insect flower‐visitor community. Pollinating insects were significantly attracted to inflorescences with crab spiders compared to inflorescences without crab spiders for two plant species, and herbivorous insects were attracted to inflorescences with crab spiders for one of these plant species. The two flowering plant species with increased pollinator visitation showed increased seed weights for plants with crab spiders, indicating crab spider presence indirectly increased pollination. 4. To test the UV signalling hypothesis, inflorescences with crab spiders of one plant species were observed under both a UV‐blocking plastic and a clear plastic control. Contrary to our prediction, flower‐visitors were not more likely to land on inflorescences under the clear plastic; the UV signalling hypothesis was not supported. Other unknown explanations underlie prey attraction to inflorescences with crab spiders.     

Body‐colour variation in an orb‐web spider and its effect on predation success

Animal body coloration serves several functions such as thermoregulation, camouflage, aposematism, and intraspecific communication. In some orb‐web spiders, bright and conspicuous body colours are used to attract prey. On the other hand, there are other species whose body colour does not attract prey. Using a spider species showing individual body‐colour variation, the present study aimed to determine whether or not the variation in body colour shows a correlation with predation rates. We studied the orb‐web spider (Cyclosa argenteoalba) using both field observations and T‐maze experiments, in which the prey were exposed to differently coloured spiders. Cyclosa argenteoalba has silver‐ and black‐coloured areas on its dorsal abdomen, with the ratio of these two colours varying continuously among individuals. The bright and conspicuous silver area reflects ultraviolet light. Results of both field observations and colour choice experiments using Drosophila flies as prey showed that darker spiders have a greater chance of capturing prey than silver spiders. This indicates that body‐colour variation affects predation success among individuals and that the bright silver colour does not function to attract prey in C. argenteoalba.     

Attraction to monoterpenes and beetle‐produced compounds by syntopic Ips and Dendroctonus bark beetles and their predators

• 1 Bark beetles are significant mortality agents of conifers. Four beetle species, the pine engraver Ips pini, the six‐spined pine engraver Ips calligraphus sub. ponderosae, the southern pine beetle Dendroctonus frontalis, and the western pine beetle Dendroctonus brevicomis, cohabitate pines in Arizona.
• 2 A pheromone trapping study in ponderosa forests of Arizona determined the attraction of beetles to conspecific and heterospecific pheromone components in the presence and absence of host volatiles, and tested whether predators differ in their attraction to combinations of pheromone components and tree monoterpenes.
• 3 All four bark beetle species differed in their responses to heterospecific lures and monoterpenes. Ips calligraphus was the only species that increased in trap catches when heterospecific lures were added. Heterospecific lures did not inhibit the attraction of either Dendroctonus or Ips species. The replacement of myrcene with α‐pinene increased the attraction of Dendroctonus, whereas the addition of α‐pinene had mixed results for Ips. The prominent predators Temnochila chlorodia and Enoclerus lecontei were more attracted to the I. pini lure than the D. brevicomis lure, and the combination of the two lures with α‐pinene was most attractive to both predator species.
• 4 Cross attraction and limited inhibition of bark beetles to heterospecific pheromones suggest that some of these species might use heterospecific compounds to increase successful location and colonization of trees. Predator responses to treatments suggest that tree volatiles are used to locate potential prey and predators are more responsive to Ips than to Dendroctonus pheromone components in Arizona.

     

Monitoring codling moth (Lepidoptera: Tortricidae) in orchards treated with pear ester and sex pheromone combo dispensers

Monitoring codling moth, Cydia pomonella (L.), with its sex pheromone (E,E)‐8,10‐dodecadien‐1‐ol (codlemone) alone or in combination with plant volatiles (PH‐plant volatile lures) with and without the addition of an acetic acid (AA) lure was compared in apple and walnut orchards treated with PVC Cidetrak^® dispensers (CM‐DA Combo) loaded with 60 mg pear ester, ethyl (E, Z)‐2,4‐decadienoate (PE) and 185 mg codlemone. Lures were also evaluated in untreated apple and walnut orchards and apple orchards treated with Cidetrak^® dispensers (CM) loaded with 120 mg codlemone. Traps with codlemone lures caught more moths than PE plus AA but similar numbers as traps with the PH‐PE lure in untreated apple and walnut orchards. The PH‐PE outperformed codlemone lures in apple orchards treated with CM dispensers. Codlemone outperformed PH‐PE lures in apple but not in walnut orchards treated mid‐season with CM‐DA Combo dispensers. Combining AA with PE significantly increased moth catch and together they performed similarly to the PH‐PE lure in all dispenser treatments in apple orchards. However, adding AA with the PH‐PE lure did not increase moth catches. The addition of AA to any of the lures tested except codlemone alone significantly increased the catch of females. Adding AA to either PE or the PH‐PE lure created a similarly attractive lure in orchards treated with CM‐DA Combo dispensers. Combining (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) with codlemone in a combinational lure plus AA performed as well as any lure tested in apple orchards treated with CM‐DA Combo dispensers. Combinational lures loaded with either (E,E)‐farnesol, (E)‐β‐farnesene or DMNT performed significantly better than the PH‐PE lure in apple orchards treated with CM‐DA Combo dispensers only in the first generation. Both PH‐DMNT and PH‐farnesol lures were comparable to PH‐PE, except that the PH‐farnesol lure was less attractive to female moths.     

Indirect effects of phytochemicals on offspring performance of Queensland fruit fly,Bactrocera tryoni (Diptera: Tephritidae)

Phytochemical lures such as methyl eugenol (ME) and cue‐lure are used in the management of Bactrocera fruit flies for monitoring and control. These lures are not just attractants, but also trigger physiological changes in males that lead to enhanced mating success. Additionally, in the cue‐lure‐responsive Bactrocera tryoni, females mated with lure‐fed males exhibit changes in fecundity, remating receptivity and longevity. While the lures show current generation effects, no research has been carried out on possible multigenerational effects, although such effects have been hypothesized within a ‘sexy‐son’ sexual selection model. In this study, we test for indirect, cross‐generational effects of lure exposure in F1offspring of B. tryoni females mated with cue‐lure‐fed, zingerone‐fed and lure‐unfed (=control) males. The F1 attributes we recorded were immature development time, immature survival, adult survival and adult male lure foraging. No significant differences were found between treatments for any of the three life‐history measurements, except that the offspring sired by zingerone‐fed males had a longer egg development time than cue‐lure and control offspring. However, indirect exposure to lures significantly enhanced the lure‐foraging ability of F1 adult males. More offspring of cue‐lure‐fed males arrived at a lure source in both large flight cages and small laboratory cages over a 2‐h period than did control males. The offspring of zingerone‐fed males were generally intermediate between cue‐lure and control offspring. This study provides the first evidence of a next generation effect of fruit fly male lures. While the results of this study support a ‘sexy‐son’ sexual selection mechanism for the evolution of lure response in Bactrocera fruit flies, our discussion urges caution in interpreting our results in this way.     

The Disruption Hypothesis Does Not Explain Mate‐Choice Copying in the Guppy (Poecilia reticulata)

In some species, female mate choice is non‐independent as, under certain circumstances, females may copy the mate choice of other nearby females. One standard experimental protocol used to test for mate‐choice copying is the mate‐choice ‘reversal’ protocol. In this protocol, a focal female is allowed to choose between two males as potential mates and then is presented with an opportunity to see another female (i.e. the model female) choose the male that she did not initially choose. The focal is subsequently allowed to again choose between the same set of males. An observed reversal of her initial choice in this second preference test has been previously interpreted as evidence for mate‐choice copying. Alternatively, it has recently been proposed that environmental events, such as seeing the mate choice of nearby females that occur within the visual field of a female actively engaged in mate assessment, may ‘disrupt’ her decision‐making behavior and consequently alter the consistency of her mating preference, and may thus cause mate‐choice reversals. The disruption hypothesis predicts that if a model female is placed near the male that the focal female initially chose, the latter's mate preference would be disrupted and she would subsequently and consistently prefer the male that she initially rejected. Here we examined whether the disruption hypothesis explains mate‐choice copying in the guppy (Poecilia reticulata). Our results do not support this hypothesis, but rather provide further support for mate‐choice copying in the guppy.     

Forest edges enhance mate‐finding in the invasive European gypsy moth,Lymantria dispar

Habitat type, fragmentation, and edge effects can play important roles in the mate‐finding abilities of many species. These effects can be particularly pronounced in low‐density populations, which are often found at the margins of species' ranges or at the leading edge of an invasion. The European gypsy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae), is a non‐native insect defoliator in the USA and Canada, where flightless females attract male moths through pheromone production and local extirpation of low‐density populations can be due to mate‐finding failure. To assess the effects of habitat edges on the ability of gypsy moths to find mates, we conducted a release experiment with male gypsy moths using female‐baited trap arrays in fields, at forest edges, and in the forest interior. Reduced mate‐finding was expected in fields and near forest edges based on geographic variation in invasion rates, male flight behavior, and pheromone plume dynamics. However, we found that mate‐finding was highest at forest edges, reduced in fields, and lowest within the forest interior. Within an array, traps closest to the forest edge also had the highest mate‐finding, suggesting that habitat characteristics can influence male flight direction in addition to pheromone cues. These results suggest that a moderate level of forest fragmentation enhances mate‐finding ability in the gypsy moth. Understanding the relationship between habitat heterogeneity and mate‐finding success in invasive species can inform predictions of future spread and assist with management plans that target mating disruption.     

A specialized araneophagic predator's short‐term nutrient utilization depends on the macronutrient content of prey rather than on prey taxonomic affiliation

A specialist predator that has a specialized diet, prey‐specific prey‐capture behaviour and a preference for a particular type of prey may or may not be specialized metabolically. Previous studies have shown that jumping spiders of the genus Portia prey on other spiders using prey‐specific prey‐capture behaviour, prefer spiders as prey to insects and gain long‐term benefits in terms of higher survival and growth rates on spider diets than on insect diets. However, it is unclear whether there are substances uniquely present in spiders on which Portia depends, or, alternatively, spiders and insects all contain more or less the same nutrients but the relative amounts of these substances are such that Portia perform better on a spider diet. These questions are addressed by testing the hypothesis that prey specialization includes metabolic adaptations that allow Portia an enhanced nutrient extraction or nutrient utilization efficiency when feeding on spider prey compared with insect prey. Three groups of Portia quei Zabka are fed either their preferred spider prey or one of two types of flies (Drosophila melanogaster Meigen) that differ in nitrogen and lipid content. Portia quei shows a higher feeding rate of high‐protein flies than of high‐lipid flies and spiders but, after 5 days of feeding, there is no significant difference in growth between treatments, and the diets lead to significant changes in the macronutrient composition of P. quei as a result of variable extraction and utilization of the prey. The short‐term utilization of spider prey is similar to that of high‐lipid flies and both differ in several respects from the utilization of high‐protein flies. Thus, the short‐term nutrient utilization is better explained by prey macronutrient content than by whether the prey is a spider or not. The results suggest that spider prey may have a more optimal macronutrient composition for P. quei and that P. quei does not depend on spider‐specific substances.