The Effect of Predator Chemical Cue Age on Antipredator Behavior in the Wolf Spider Pardosa milvina (Araneae: Lycosidae)

The wolf spider, Pardosa milvina, exhibits reduced movement when detecting chemical cues (silk and excreta) from a larger wolf spider, Hogna helluo. We tested if cue age influenced Pardosa activity. Pardosa response was measured during 1-h trials using video-tracking equipment. Five treatments of predator cues were used: 5-day-old, 1-day-old, 1-h-old, and fresh cues and a control lacking predator cues. Pardosa moved significantly more slowly on substrates with fresh or 1-h-old cues compared to all other treatments and spent less time walking in all Hogna treatments relative to the control except with 5-day-old cues. Pardosa survived longer in the presence of Hogna with fresh compared to older cues. Prey may evaluate cue age as a measure of predation risk and grade antipredator behavior accordingly.     

Fitness costs and benefits of antipredator behavior mediated by chemotactile cues in the wolf spider Pardosa milvina (Araneae: Lycosidae)

Animals may exhibit a variety of defensive behaviors in thepresence of indirect predator cues. Such behavior offers immediatefitness benefits but may also incur substantial foraging andreproductive costs. We measured shifts in space use (verticalclimbing) by the wolf spider Pardosa milvina induced by chemotactilecues (silk and excreta) from a co-occurring predatory wolfspider Hogna helluo. We then measured foraging and reproductive costs, as well as survival benefits, of this behavior. For 2weeks, we maintained mated adult female Pardosa in plasticcontainers with one of three treated peat moss substrates:a container previously occupied by a conspecific for 3 days,a container previously occupied by an adult Hogna for 3 days,and a container devoid of either cue (control). We measuredprey capture efficiency, body condition, egg sac production,egg sac weight, and egg number for individuals in each treatment.We also counted the number of Pardosa that survived and exhibitedclimbing behavior in the presence of a live Hogna with andwithout silk and excreta cues. Pardosa climbed container wallssignificantly more often in the presence of Hogna silk andexcreta relative to other treatments. Pardosa exposed to Hognacues coupled with live Hogna survived significantly longerthan spiders that had no predator cues available. Pardosa placedin containers with Hogna cues, but no Hogna, lost weight morequickly, ate fewer prey, were in poorer body condition, producedlighter egg sacs, and produced fewer eggs than spiders in controlor conspecific treatments.     

Sex‐Specific Response of Pardosa milvina (Araneae: Lycosidae) to Experience with a Chemotactile Predation Cue

Predators frequently leave behind chemical information (i.e., semiochemicals such as pheromones or kairomones) that can be detected by their prey and used to avoid areas where predators are likely present. Prey that have interacted indirectly with predators via chemical information thus may gain insight into their risk of being consumed that naïve individuals lack. Pardosa milvina (Araneae: Lycosidae) is a chemosensitive wolf spider that shows adaptive responses to chemotactile cues deposited by the larger wolf spider Tigrosa helluo. We raised offspring from P. milvina to examine the effect of experience with a predation cue on activity, foraging, and antipredator behavior. Spiders differed in activity and foraging behavior across ontogeny and between sexes, but there was no effect of experience with a predation cue. However, a sex‐specific effect of experience was found in antipredator behavior. Male spiders, but not females, used experience with a predator cue to increase their survival in the presence of a live predator. Specifically, naïve males were attacked sooner than experienced males, indicating that prior exposure to predator cues can modify Pardosa antipredator behavior. Intersexual differences in how spiders respond to experience with a predation cue likely reflect the risk of predation faced by males and females in nature.     

Species-Specificity of Chemical Signals: Silk Source Affects Discrimination in a Wolf Spider (Araneae: Lycosidae)

Female spiders deposit chemical cues that elicit male courtship behavior with silk. These cues are often assumed to be species-specific although male spiders may court in response to chemical cues of closely-related species. We used behavioral assays to test the extent of species discrimination of female chemical cues by male Schizocosa ocreata, a wolf spider (Lycosidae). Discrimination, expressed as relative courtship intensity of males, varied significantly with phylogenetic distance. Males did not discriminate between female cues of conspecifics and a sibling species, S. rovneri. Courtship response was intermediate for another species within the ocreata clade and not different from control for spiders outside the clade. These findings support the sibling species status of S. ocreata and S. rovneri, and also suggest the composition of female chemical signals is conserved across closely related wolf spider species.     

The Effect of Predator Hunger on Chemically Mediated Antipredator Responses and Survival in the Wolf Spider Pardosa milvina (Araneae: Lycosidae)

The wolf spider Pardosa milvina exhibits effective antipredator behavior (reduced movement) in the presence of silk and excreta from a larger co‐occurring predatory wolf spider Hogna helluo. As the quantity and quality of the silk and excreta may vary with the hunger state of the predator, we tested if chemical cues from a hungry vs. satiated H. helluo affected the activity level and survival of P. milvina. Pardosa milvina response was measured on substrates containing chemical cues from (1) a satiated H. helluo, (2) a H. helluo that had been withheld food for 2 wk, (3) cues from adult domestic crickets (Acheta domesticus), or (4) a blank test substrate (20 replicates/treatment). Pardosa milvina activity level was recorded on each substrate over a 30‐min period using video‐tracking equipment (Videomex‐I^®; Columbus Instruments, Columbus, OH, USA). We then measured P. milvina survival in the presence of hungry or satiated H. helluo on cues from a hungry H. helluo, satiated H. helluo, or a blank control (2 × 3 design). Pardosa milvina significantly reduced activity in the presence of H. helluo cues and showed significantly less activity in the presence of cues from a hungry H. helluo compared with a satiated one. Cue type and predator hunger state significantly affected P. milvina survival in the presence of live predators. However, cues from hungry vs. satiated H. helluo resulted in no difference in P. milvina survival. Pardosa milvina can discriminate between hungry vs. satiated predators based on silk and excreta cues alone, but differences in behavior as a result of this discrimination did not translate into increased survival in the presence of a live predator.     

Generalist predators in organically and conventionally managed grass‐clover fields: implications for conservation biological control

Organically managed agroecosystems rely in part on biological control to prevent pest outbreaks. Generalist predators (Araneae, Carabidae and Staphylinidae) are a major component of the natural enemy community in agroecosystems. We assessed the seasonal dynamics of major generalist predator groups in conventionally and organically managed grass–clover fields that primarily differed by fertilisation strategy. We further established an experiment, manipulating the abundant wolf spider genus Pardosa, to identify the importance of these predators for herbivore suppression in the same system and growth period. Organic management significantly enhanced ground‐active spider numbers early and late in the growing season, with potentially positive effects of plant cover and non‐pest decomposer prey. However, enhancing spider numbers in the field experiment did not improve biological control in organically managed grass–clover fields. Similar to the survey results, reduced densities of Pardosa had no short‐term effect on any prey taxa; however, spider guild structure changed in response to Pardosa manipulation. In the presence of fewer Pardosa, other ground‐running spiders were more abundant; therefore, their impact on herbivore numbers may have been elevated, possibly cancelling increases in herbivore numbers because of reduced predation by Pardosa. Our results indicate positive effects of organic farming on spider activity density; however, our survey data and the predator manipulation experiment failed to find evidence that ground‐running spiders reduced herbivore numbers. We therefore suggest that a positive impact of organic fertilisers on wolf spiders in grass–clover agroecosystems may not necessarily improve biological control when compared with conventional farming.     

拟环纹豹蛛雄蛛触肢上黑白相间毛饰物的功能

狼蛛科雄蛛附肢上多样化的饰装往往与求偶行为相偶联,这些特殊的饰装通常被认为是雌性选择的结果。拟环纹豹蛛Pardosa pseudoannulata,属狼蛛科豹蛛属,雄蛛触肢胫节密被白毛,跗舟密被黑毛,具有典型的性二型现象;同时,只有成熟的雄蛛才展现触肢黑白相间的毛饰物。推测拟环纹豹蛛雄蛛触肢这种黑白相间的毛饰物可能在物种识别中具重要作用。在室内我们拟通过涂抹操作对拟环纹豹蛛雄蛛触肢黑白相间毛饰物的功能进行分析。实验分为4组,分别是对照组(A组,雄蛛不做任何处理)、雄蛛触肢白色胫节全部涂成黑色(B组)、雄蛛触肢黑色跗舟全部涂成白色(C组)和雄蛛触肢的黑色跗舟被涂成黑色(D组),然后采用雌雄配对进行求偶交配行为测定。实验结果表明,B组雄蛛的交配成功率显著低于A、C和D组的雄蛛,而后3组雄蛛的交配成功率无显著差异。相反,B组雄蛛被雌蛛相食百分率显著高于其它3组。可见拟环纹豹蛛雄蛛触肢上黑白相间毛饰物,尤其是其胫节上的白色饰物在雌蛛种间识别中起重要作用。     

Wolf spider predator avoidance tactics and survival in the presence of diet-associated predator cues (Araneae: Lycosidae)

Some prey can distinguish between chemical cues from predators fed different diets. Here we document the first evidence of diet-based chemical discrimination of predators in a terrestrial arthropod and measure the survival value of behavioural responses to predator chemical cues. We tested activity level and avoidance behaviour of the wolf spider, Pardosa milvina, to faeces and silk associated with the predatory wolf spider, Hogna helluo, fed either P. milvina or crickets (Acheta domesticus). We then measured survival of Pardosa in the presence of Hogna when placed on blank paper or paper previously occupied by Hogna fed either crickets or Pardosa. Filter paper previously occupied by Hogna from each diet treatment or a blank control were simultaneously presented to adult female Pardosa among four treatment pairs (N=15/treatment): (1) blank paper/blank paper, (2) Hogna fed crickets/blank, (3) Hogna fed Pardosa /blank and (4) Hogna fed Pardosa / Hogna fed crickets. Cues from Hogna fed either crickets or Pardosa elicited significantly less activity relative to blank controls. Cues from Hogna fed Pardosa elicited a significantly greater reduction in activity than Hogna fed crickets. When given a choice, Pardosa initially chose the blank substrate significantly more often than either substrate with Hogna cues. Spiders survived longer in the presence of cues from either Hogna diet treatment relative to blank paper, but there was no significant effect of predator diet on survival. Results suggest diet-based predator cues elicit different levels of activity in Pardosa that reduce predation in the presence of Hogna. Copyright 2001 The Association for the Study of Animal Behaviour.     

同种雄性竞争对手的存在对星豹蛛雄蛛求偶和交配行为的影响

越来越多的研究发现,雄性产生精子(精液)也需付出代价。雄性除了依据配偶质量和竞争对手的竞争强度适应性调整生殖投入外,雄性在求偶和交配行为上也相应产生适应性反应,求偶和交配行为具有可塑性。目前雄性求偶和交配行为可塑性研究主要集中于雌性多次交配的类群中,在雌性单次交配的类群中研究甚少。以雌蛛一生只交配一次而雄蛛可多次交配的星豹蛛为研究对象,比较:(1)前一雄性拖丝上信息物质对后续雄蛛求偶和交配行为的影响,(2)雌雄不同性比对雄蛛求偶和交配行为的影响。研究结果表明,星豹蛛前一雄蛛拖丝上的信息物质对后续雄蛛求偶潜伏期、求偶持续时间和交配持续时间都没有显著影响,但前一雄蛛拖丝上的信息物质对后续雄蛛求偶强度有显著抑制作用。同时,性比对星豹蛛雄蛛求偶和交配行为都没有显著影响。可见,星豹蛛雄蛛对同种雄性拖丝上的化学信息可产生求偶行为的适应性调整,而对性比不产生适应性反应。     

Preference for Chemical Cues Associated with Recent Prey in the Wolf Spider Hogna helluo (Araneae: Lycosidae)

In the wolf spider, Hogna helluo , we tested the response to insect and spider prey chemical cues and whether they show a preference for cues associated with prey consumed most recently. Thirty adult female H. helluo were maintained on a diet of either females of a smaller co-occurring wolf spider ( Pardosa milvina ) or domestic crickets ( Acheta domesticus ). A single P. milvina or cricket nymph was maintained on filter paper for 24 h, after which the papers from both prey sources were simultaneously presented to individual H. helluo from each diet treatment group. H. helluo locomotor behavior on each treatment and initial substrate preference was recorded (n = 15/treatment). H. helluo fed crickets showed significantly longer residence time and decreased mobility on filter paper previously occupied by a cricket; spiders fed P. milvina showed longer residence times and decreased mobility on filter paper previously occupied by P. milvina . H. helluo fed P. milvina exhibited an initial preference for substrates previously occupied by P. milvina but H. helluo fed crickets did not show a corresponding initial preference for crickets. Results suggest that H. helluo can detect distant cues associated with P. milvina but not crickets before contacting the substrate and that H. helluo respond to chemical cues from prey and show a preference for those cues associated with their most recent prey.     

Are you Paying Attention? Female Wolf Spiders Increase Dragline Silk Advertisements When Males do not Court

Females of many spider species invest in chemical advertisements to attract males, yet variation in investment relative to the presence or quality of males remains poorly understood. Males of the wolf spider Pardosa milvina court females longer and more intensively when in contact with female silk and also court more intensively when encountering silk from virgin rather than mated females; therefore, females may use silk as a medium to advertise their receptivity to mate. We estimated female investment in advertisements by measuring variation in the quantity and type of silk deposited by females in the presence or absence of males and among males that varied in their courtship intensity. We measured dragline silk, cord silk, and attachment disk deposition from females on gridded sheets of paper in response to four stimuli over a 30‐min period (n = 39/treatment): (1) an intensively (high) courting male with access to female silk, (2) a weakly courting or non‐courting male (low) without access to female silk, (3) no male present, but female silk present (silk control), and (4) no stimulus present (control). Females produced significantly more dragline silk and significantly less cord silk in the presence of low‐courting males compared to any other treatment, but we found no difference in attachment disk deposition across treatments. Our results suggest that females invest more heavily in dragline deposition when encountering low‐courting males. Additional studies are necessary to determine the relative role of different silk types in male–female sexual communication.     

Costs and benefits of freezing behaviour in the harvestman Eumesosoma roeweri (Arachnida, Opiliones)

Animals present an enormous variety of behavioural defensive mechanisms, which increase their survival, but often at a cost. Several animal taxa reduce their chances of being detected and/or recognized as prey items by freezing (remaining completely motionless) in the presence of a predator. We studied costs and benefits of freezing in immature Eumesosoma roeweri (Opiliones, Sclerosomatidae). Preliminary observations showed that these individuals often freeze in the presence of the syntopic predatory spider Schizocosa ocreata (Araneae, Lycosidae). We verified that harvestmen paired with predators spent more time freezing than when alone or when paired with a conspecific. Then, we determined that predator chemical cues alone did not elicit freezing behaviour. Next, we examined predator behaviour towards moving/non-moving prey and found that spiders attacked moving prey significantly more, suggesting an advantage of freezing in the presence of a predator. Finally, as measure of the foraging costs of freezing, we found that individuals paired with a predator for 2 h gained significantly less weight than individuals paired with a conspecific or left alone. Taken together, our results suggest that freezing may protect E. roeweri harvestmen from predatory attacks by wolf spiders, but at the cost of reduced food and/or water intake.     

Influence of landscape structure and farming practice on body condition and fecundity of wolf spiders

Structurally complex landscapes and organic management have been shown to augment natural pest enemy populations on arable land. Here, body condition and reproductive capacity of wolf spiders were studied to see if these traits can explain the larger populations in these environments. Females of Pardosa spiders (Araneae: Lycosidae) were collected at 7 organically and 7 conventionally managed fields situated in landscapes with different proportions of perennial crops, annual crops, forest, and different numbers and sizes of fields. Body condition (relative female weight) and fecundity (number of offspring and relative egg sac weight) were measured for each captured spider. In contrast to the hypothesis, Pardosa females caught in fields situated in landscapes dominated by large fields of annual crops had superior body condition. Farming practice had no effect on either body condition or fecundity measures. It is suggested that increased spider body condition in homogeneous landscapes may be due to less competition for available resources, although temporal variation should be included before drawing final conclusions on spiders’ body condition in the agricultural landscape.     

Male chemical cues as reliable indicators of infection in the wolf spider Schizocosa ocreata

Sexual signals can convey important information about mate quality, such as critical information about a signaler's health status, helping an individual to avoid infected or immunocompromised conspecifics. Chemical signals are especially important in this context, because they represent an honest and dynamic signaling modality that receivers can use to make updated mate choice decisions to avoid compromising their own health. In this study, we investigated the viability of male chemical cues in the wolf spider Schizocosa ocreata as a reliable indicator of health status. Using video playback with images of an average male that is simultaneously paired with male cuticular compounds on filter paper, we show that females are more receptive to videos paired with cues from control males rather than infected males. We also show that these cuticular compounds can be isolated and retain similar female behavioral responses when extracted with a nonpolar solvent, suggesting that these cuticular compounds may not be just complex hydrocarbons, but a combination of cuticular compounds. This is the first evidence for female discrimination and recognition of male chemical cues in this species, which opens up important new avenues of research in a well‐studied species with complex multimodal signaling.     

Navigation by Male Crab Spiders <Emphasis Type="Italic">Misumenoides formosipes</Emphasis> (Araneae: Thomisidae): Floral Cues May Aid in Locating Potential Mates

The crab spider Misumenoides formosipes is an ambush predator whose males search for relatively sedentary females within a heterogeneous habitat. Females are receptive to mating immediately after their adult molt and a male biased adult sex ratio together with precopulatory guarding places a premium on male ability to locate females quickly. It is unknown what cues males use to find females; we report here on male movements in association with floral cues. Males in field trials moved towards inflorescences more frequently when both visual and chemical cues were available, than when chemical cues were eliminated. Males in lab trials chose an inflorescence over leaf substrates even in the absence of visual cues. These findings support the hypothesis that M. formosipes males could utilize floral chemistry as a navigational cue in mate searches.     

Interacting Effects of Leg Autotomy and Exposure to Predator Cues on Survival in A Wolf Spider (<Emphasis Type="Italic">Pardosa valens</Emphasis>)

Chemical cues from predators (kairomones) are used by many aquatic and terrestrial animals when deciding on behavioral responses to predation threats. These responses may also be affected by the animal’s physiological state (e.g., nutrition level, parasitism, or prior injury), which could alter normal responses to kairomones. In this study, we examined effects of leg autotomy (the voluntary sacrifice of a leg) on subsequent responses to predator chemical cues in females of the riparian-zone wolf spider Pardosa valens. In a fully-crossed design, spiders with all legs intact or with one leg removed were exposed to one of two cue treatments for 90 min: a control (no predator cue) or one with chemical cues (silk and excreta) from a larger sympatric wolf spider, Rabidosa santrita. We then introduced an R. santrita into each container, and recorded subsequent survival of P. valens. Survivorship was significantly higher for individuals previously exposed to predator cues than for those in the control group; however, autotomy had no effect on survivorship, which was similar for both intact and autotomized spiders in both the predator-cue and control treatments. In addition, although P. valens were more likely to be found off the substrate than on it when the predator was added in each of the four treatment pairings, this initial position did not influence survivorship. These results therefore indicate that P. valens can behaviorally respond to predator kairomones in ways that reduce their risk of predation, but that this response is unaffected by the prior sacrifice of a leg.     

The reactions of two species of aphid to chemotactile cues from a wolf spider match their vulnerability to predation

Various strategies have evolved to protect animals from predators. We explored the activity and predation risk experienced by two species of aphid. Both species will drop from plants when disturbed and face a suite of predators, including wolf spiders, when they reach the ground. We focused on Aphis fabae Scopoli and Aphis nerii Boyer de Fonscolombe (Hemiptera: Aphididae, Aphidini); A. nerii sequesters cardiac glycosides when it feeds on milkweed. We explored the interactions between these aphids and the wolf spider Pardosa milvina Hentz (Araneae: Lycosidae) that is likely a predator they encounter when they are not on their host plants. We hypothesized that there would be differences in the susceptibility of the two species to predation and that the more vulnerable species would react more strongly to substrate-borne cues deposited by the spider. We predicted that any behavioral reactions that the aphid displayed in response to predator cues would be effective in reducing risk. We documented the activity of each aphid species on chemotactile cues from P. milvina and measured predation rate in arenas with and without those same cues. Aphis fabae altered their activity in the presence of P. milvina cues but A. nerii did not. Likewise, A. fabae was more susceptible to predation by P. milvina when no cues were present, but when cues were present, predatory success was much lower. Aphis nerii, the less desirable prey for this predator, moved less and had a different locomotory pattern than A. fabae in control trials with no spider cues and so we cannot determine whether its chemical protection or activity were more important in reducing predation levels. These results provide insight into the risks faced by aphids when they are off of their host plant and in a barren environment.     

Effects of Predation Risk on Vertical Habitat Use and Foraging of Pardosa milvina

Animals face the risk of predation while engaging in regular activities, such as foraging, mate‐seeking, and reproducing. In order to avoid predation, prey can modify behavior to prevent capture. Pardosa milvina may climb in response to chemotactile cues of Hogna helluo, a larger cooccurring wolf spider, to avoid predation. The purpose of this study was to test the effects of the location of predator cues on the climbing response of P. milvina and to test how this antipredator behavior affected foraging success. In experimental arenas, when cues were on the bottom of the containers, P. milvina moved upward, and when cues were on the walls, individuals moved downward. These results suggest that P. milvina respond to H. helluo cues with general avoidance and do not automatically climb in response to the cues. As H. helluo spend most of their time on the ground, P. milvina may avoid predation by spending more time climbing in areas with H. helluo cues. The presence of predator cues significantly decreased foraging by P. milvina. But within the predator cue treatments, climbing ability had no effect on foraging, possibly due to the short height of the feeding arenas. Future studies are needed to determine if climbing by P. milvina in response to cues of H. helluo has direct and indirect negative effects on herbivores in the field.     

Predicting Predatory Outcomes in the Context of Carryover Effects: Interactions between Juvenile Frogs and Spider Predators

As representatives of organisms with complex life histories, frogs provide an ideal system to study predator‐induced carryover effects: how the risk of predation in one life stage can impact predator–prey interactions in a later stage. Invertebrate predation on frogs has been widely reported, although studies of the behavioral mechanisms underlying their interactions in the terrestrial stage have been lacking. We made detailed observations of interactions between a wolf spider (Tigrosa helluo) and Blanchard's cricket frog (Acris blanchardi) to determine factors that predict capture success and to evaluate potential carryover effects from aquatic predation risk. Juvenile frogs, reared with or without dragonfly predator cues, were placed in an arena with or without spider cues and allowed to interact with a spider. Spiders captured frogs, and an interaction between frog size and activity predicted frog survival. We found no evidence that either aquatic or terrestrial cues altered frog behavior or survival. By preying upon a demographically important life stage, spiders may contribute to population dynamics in frogs.     

Interactions between a hunting spider and a web-builder: consequences of intraguild predation and cannibalism for prey suppression

Abstract. 1. Antagonistic interactions among invertebrate predators such as intraguild predation and cannibalism have the potential to dampen top‐down impacts on shared prey at lower trophic levels. Two abundant spider predators, the large wolf spider Pardosa littoralis and the small sheet‐web builder Grammonota trivitatta co‐occur on the salt marshes of eastern North America where they both attack planthoppers (Prokelisia spp.), the dominant herbivores on the marsh. Experiments both in the laboratory and field were used to assess the incidence of intraguild predation and cannibalism in these spiders and elucidate how such antagonistic interactions influence planthopper suppression. 2. Functional response experiments showed that with an increase in planthopper prey density, Grammonota captured more prey but not a higher proportion of that offered. Pardosa exhibited the same response when Grammonota were offered as intraguild prey. Both functional responses were type I over the range of prey densities offered. 3. Grammonota is moderately cannibalistic, and the presence of planthopper prey reduced the incidence of cannibalism. 4. Factorial experiments in the laboratory showed that Pardosa but not Grammonota reduced planthopper prey populations when prey density was low. By contrast, at high prey densities, both Pardosa and Grammonota had significant adverse effects on planthopper populations. Moreover, there was an interactive effect such that Grammonota reduced planthopper populations relatively more when Pardosa was absent than when it was present. 5. There was direct evidence for the intraguild predation of Grammonota by Pardosa such that fewer Grammonota survived in the presence of Pardosa than when it was absent. This result occurred whether planthopper prey were abundant or not. 6. Field releases of Grammonota in open plots resulted in significant but small decreases in the density of planthopper prey, both nymphs and adults. 7. Enhancing densities of Pardosa in open plots resulted in Grammonota suppression. The intraguild predation of Grammonota at this enhanced Pardosa density, however, did not preclude Pardosa from significantly reducing planthopper populations. 8. Although there was evidence that Grammonota reduced planthopper populations and that the intraguild predation of Grammonota by Pardosa occurred, the strength of these interactions was relatively weak given the low consumption rate of planthoppers by Grammonota (< 3 day^–1) and Grammonota by Pardosa (≈ 2 day^?1). Thus, weak asymmetric intraguild predation among spiders on the marsh likely dampens but does not eliminate the ability of Pardosa to exert significant top‐down control on planthopper populations.