Wolf Spider Research Articles

Divergence in gut bacterial community between females and males in the wolf spider Pardosa astrigera

Sex is one of the important factors affecting gut microbiota. As key predators in agroforestry ecosystem, many spider species show dramatically different activity habits and nutritional requirements between females and males. However, how sex affects gut microbiota of spiders remains unclear. Here, we compared the composition and diversity of gut bacteria between female and male Pardosa astrigera based on bacterial 16S rRNA gene sequencing. Results showed that the richness of bacterial microbiota in female spiders was significantly lower than in male spiders (p < .05). Besides, β‐diversity showed a significant difference between female and male spiders (p = .0270). The relative abundance of Actinobacteriota and Rhodococcus (belongs to Actinobacteriota) was significantly higher in female than in male spiders (p < .05), whereas the relative abundance of Firmicutes and Acinetobacter (belongs to Proteobacteria) and Ruminococcus and Fusicatenibacter (all belong to Firmicutes) was significantly higher in male than in female spiders (p < .05). The results also showed that amino acid and lipid metabolisms were significantly higher in female than in male spiders (p < .05), whereas glycan biosynthesis and metabolism were significantly higher in male than in female spiders (p < .05). Our results imply that sexual variation is a crucial factor in shaping gut bacterial community in P. astrigera spiders, while the distinct differences of bacterial composition are mainly due to their different nutritional and energy requirements.

A new species of Trabea Simon, 1876 (Araneae: Lycosidae) from West Africa fills a huge zoogeographical gap

In the collections from Mount Nimba (Ivory Coast) made by M. Lamotte around 1950 and deposited in the Muséum National d'Histoire Naturelle (Paris), a new species of Trabea was found. This is the first species from West Africa. In view of the known distribution range of this wolf spider genus, the discovery is remarkable and fills a large zoogeographical gap. More species of Trabea are to be expected from highlands in West Africa.

Integrated transcriptomics and proteomics provide new insights into the cadmium-induced ovarian toxicity on Pardosa pseudoannulata

Cadmium (Cd) pollution is intractable heavy metal pollution in the farmland ecosystem, posing a life-threatening challenge to the paddy field organisms. Spiders are riveting animal biomarkers for evaluating Cd-induced toxicity, yet the effects of long-term Cd toxicity on spider reproductive function and its underlying mechanism remain unclear. In the present study, we found that Cd exposure impaired the antioxidant enzyme system in the wolf spider Pardosa pseudoannulata and decreased the concentration of four antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase, and peroxidase) (p < 0.05). The content of vitellogenin and the number of hatched spiderlings were also dramatically reduced under Cd stress (p < 0.05), indicating that Cd stress could vitiate the fecundity of P. pseudoannulata. Moreover, a total of 10,511 differentially expressed genes (DEGs) and 391 proteins (DEPs) were yielded from the ovarian transcriptome and proteome, and a mass of genes and proteins involved in protein processing in endoplasmic reticulum (ER) were significantly down-regulated. DEGs and DEPs directly encoding the antioxidant enzyme system and/or vitellogenesis were also distinctively down-regulated. In addition, we illustrated that the PI3K-AKT signaling pathway might play a crucial role in regulating protein synthesis, cell cycle, growth, differentiation and survival in P. pseudoannulata. The effects of protein processing in ER and PI3K-AKT pathways could further trigger transcriptional factor Forkhead shackling the protein synthesis and cell growth process. Collectively, this integrated analysis identified the Cd-induced reproductive toxicity on P. pseudoannulata and provided multifaceted insights to investigate the molecular mechanisms of spiders to Cd pollution.

Comparative analysis unveils the cadmium-induced reproductive toxicity on the testes of Pardosa pseudoannulata

Cadmium (Cd) pollution is one of the most serious heavy metal pollutions in the world, which has been demonstrated to cause different toxicities to living organisms. Cd has been widely suggested to cause reproductive toxicity to vertebrates, yet its reproductive toxicity to invertebrates is not comprehensive. In this study, the wolf spider Pardosa pseudoannulata was used as a bioindicator to evaluate the male reproductive toxicity of invertebrates under Cd stress. Cd stress had no effect on the color, size and length of testis. However, Cd significantly increased the contents of catalase, glutathione peroxidase and malondialdehyde, the antioxidants in the testis of P. pseudoannulata. Then we analyzed the transcriptome of testis exposed to Cd, and identified a total of 4739 differentially expressed genes (DEGs) compared to control, with 2368 up-regulated and 2371 down-regulated. The enrichment analysis showed that Cd stress could affect spermatogenesis, sperm motility, post-embryonic development, oxidative phosphorylation and metabolism and synthesis of male reproductive components. At the same time, the protein-protein interaction network was constructed with the generated DEGs. Combined with the enrichment analysis of key modules, it revealed that Cd stress could further affect the metabolic process in testis. In general, the analysis of testicular damage and transcriptome under Cd stress can provide a novel insight into the reproductive toxicity of Cd on rice filed arthropods and offer a reference for the protection of rice filed spiders under Cd pollution.

The effects of environmental light on the role of male chemotactile cues in wolf spider mating interactions

The effects of environmental light on the role of male chemotactile cues in wolf spider mating interactions

Cuticular compounds inhibit cannibalism of early-instar spiderlings by pulli-carrying Pardosa pseudoannulata females.

Cannibalism is common in spiders. Wolf spider (Lycosidae) females, which exhibit extensive maternal care, have been reported to cannibalize less when they are carrying egg sacs and juveniles. In a laboratory experiment, we demonstrated that cannibalism of early-instar spiderlings (EIS) by a wolf spider (Pardosa pseudoannulata) mother was almost completely inhibited when she was carrying spiderlings. Compared with virgin and mated-females, mother spiders tolerated more and predated fewer spiderlings, including gregarious pulli and newly dispersed spiderlings (NDS). Cannibalism of EIS by females during their reproductive period exhibited a V-shaped pattern, with a gradual decrease from the egg sac-carrying to pulli-carrying (PC) stage, and a recovery from the PC stage to post-reproductive (PR) stage. Notably, there was 0 cannibalism at the PC stage. PC females exhibited no interest in pulli, while PR females were attracted to and predated pulli and NDS as they did their natural prey, Nilaparvata lugens. Interestingly, PC females captured and released NDS in a foraging assay, although attraction was observed from olfactometer measurements. PC mothers possessed a cuticular volatile profile that was closer to that of pulli and NDS than to that of PR females. Moreover, NDS cuticular extract provoked an electrophysiological response in legs of PC females. Therefore, cuticular compound-mediated chemical communication may be involved in inhibiting cannibalism of EIS by spider mothers, and especially in eliminating cannibalism by PC mothers. Future studies will aim to characterize the specific cuticular compounds and chemoreception mechanism in females, which will facilitate our understanding of intraspecific recognition and cannibalism in spiders.

Integrative analysis identifies the safety of transgenic Cry1Ab rice to non-target spider Pardosa pseudoannulata

Cry1Ab toxin has been successfully integrated into crops (e.g., rice and cotton) for pest control. Concomitantly, the environmental safety assessment of non-target organisms exposed to transgenic crops has become an essential task. Spiders grant a new perspective on the influence of the transgenic toxin on invertebrates, but the mechanisms of Cry1Ab bioaccumulation, adaptation, and safety in spiders remain unclear. In this study, we identified that the wolf spider Pardosapseudoannulata, fed with Nilaparvata lugens enriched with Cry1Ab protein, suffered no significant toxicity in terms of body mass, carapace width, and survival rate, except the prolonged developmental duration in 7th ∼ 8th instars. The overall activities of four detoxifying enzymes (SOD, POD, CAT, and GSH-Px) were not altered in four organs of adults and spiderlings. Comparison analyses of whole-body transcriptomes revealed 1,480 differentially expressed genes (DEGs), and down-regulated cuticle encoding genes were considered as a segment for the prolonged developmental duration under Cry1Ab exposure. Further venom gland transcriptome sequencing analysis found that a total of 31 toxin encoding genes were up-regulated under Cry1Ab protein stress, indicating that the spiders needed to inject more venom to digest the external protein. Furthermore, gene expression profiles of ganglia transcriptome showed that Cry1Ab protein did not generate DEGs involved in neuron sensitivity in spiders. Behavioral experiments verified that both Cry1Ab and Cry1Ab-free spiders were in line with the Holling type II functional response model. In summary, the data provide multi-level views to assess the safety of genetically modified crops on non-target arthropods.

Island hoppers: Integrative taxonomic revision of Hogna wolf spiders (Araneae, Lycosidae) endemic to the Madeira islands with description of a new species.

Because of their ability for aerial dispersal using silk and preference for open habitats, many wolf spiders are formidable colonisers. Pioneering arachnologists were already aware of the large and colourful wolf spiders in the Madeira archipelago, currently included in the genus Hogna Simon, 1885. The origins were investigated and species boundaries of Madeiran Hogna examined by integrating target-gene and morphological information. A multi-locus phylogenetic analysis of a thorough sampling across wolf-spider diversity suggested a single origin of Madeiran endemics, albeit with low support. Divergence time estimation traced back their origin to the late Miocene, a time of major global cooling that drove the expansion of grasslands and the associated fauna. Morphological examination of types and newly collected material revealed a new species, hereby described as H.isambertoi Crespo, sp. nov. Additionally, H.blackwalli is revalidated and three new synonymies are proposed, namely H.biscoitoi Wunderlich, 1992, junior synonym of H.insularum Kulczynski, 1899, H.schmitzi Wunderlich, 1992, junior synonym of H.maderiana (Walckenaer, 1837), and Arctosamaderana Roewer, 1960 junior synonym of H.ferox (Lucas, 1838). Species delimitation analyses of mitochondrial and nuclear markers provided additional support for morphological delineations. The species pair H.insularum and H.maderiana, however, constituted an exception: the lack of exclusive haplotypes in the examined markers, along with the discovery of intermediate forms, pointed to hybridisation between these two species as reported in other congeneric species on islands. Finally, the conservation status of the species is discussed and candidates for immediate conservation efforts are identified.

Trophic transfer of heavy metals along a pollution gradient in a terrestrial agro-industrial food web

Heavy metal contamination across the food web is a growing concern because of increasing environmental discharges in industrial zones, atmospheric transport, and deposition and erosion during rainfall events. We examined the transfer pathways of chromium (Cr) and nickel (Ni) through a terrestrial trophic web and investigated the potential for their bioaccumulation along the trophic chain. Soil, plants, arthropods, and vertebrates were sampled from different localities in the south of Cairo (El-Tebbin, Egypt) and the amounts of Cr and Ni from these samples were measured. We also computed a body condition index (BCI) for vertebrates to estimate individual health and fitness levels in relation to heavy metal concentrations in the liver. The levels of Cr and Ni varied significantly among the samples. Lower trophic levels showed a tendency for biomagnification, while higher trophic levels showed possible biodilution of the two heavy metals: arthropods, amphibians, and lizards concentrated more Cr and Ni than the other taxonomic groups; conversely birds and small mammals generally showed lower levels of Cr and Ni. A negative relationship was obtained when the concentrations of Cr in the soil, plant, and arthropods, and the concentrations of Ni in the wolf spider were plotted as a function of the distance to the industrial area. A significant inverse relationship was found between the Ni concentration of liver and body length, while body mass had no significant effect. Our study thus highlights the varied effects of heavy metal concentrations across a complex food web at different distances from the pollution source, and the need for further studies of their effect on multiple species in an ecosystem.

The effects of prey lipid on female mating and reproduction of a wolf spider.

As predators, the macronutrients spiders extract from their prey play important roles in their mating and reproduction. Previous studies of macronutrients on spider mating and reproduction focus on protein, the potential impact of prey lipid content on spider mating and reproduction remains largely unexplored. Here, we tested the influence of prey varying in lipid content on female mating, sexual cannibalism, reproduction, and offspring fitness in the wolf spider Pardosa pseudoannulata. We acquired 2 groups of fruit fly Drosophila melanogaster that differed significantly in lipid but not protein content by supplementing cultural media with a high or low dose of sucrose on which the fruit flies were reared (HL: high lipid and LL: low lipid). Subadult (i.e., 1 molt before adult) female spiders that fed HL flies matured with significantly higher lipid content than those fed LL flies. We found that the mated females fed with HL flies significantly shortened pre-oviposition time and resulted in a significantly higher fecundity. However, there was no significant difference in female spiders varying in lipid content on other behaviors and traits, including the latency to courtship, courtship duration, mating, copulation duration, sexual cannibalism, offspring body size, and survival. Hence, our results suggest that the lipid content of prey may be a limiting factor for female reproduction, but not for other behavioral traits in the wolf spiders P. pseudoannulata.

Effects of Wolf Spiders' Captive Environment on Their Locomotor and Exploratory Behaviours.

Simple SummarySince the 1960s, abuses of domestic and of wild animals that have been tamed or are held in captivity have been legally prohibited and laws ensure their well-being. Many scientific investigations carried out in this context recommend ways to adapt farming and thus to avoid physical and/or psychological suffering. Evaluations of animals’ welfare in captivity entail the need to understand in detail the fundamental behaviours of the focus species and to know the degree of their variation to be able to establish objective bases that can ensure breeding conditions that respect the animals’ welfare. Current laws do not apply to invertebrate animals (such as insects or spiders) and consideration of the welfare of these animals in captivity is neglected. Here, I compared the behaviour of wild adult spiders just after collection and that of adult spiders hatched and bred in the laboratory. My results show that captivity induced rapid changes of wild spiders’ behaviour once in captivity. Therefore, it is important to establish the best breeding conditions for the needs of both invertebrate and vertebrate animals in order to promote their well-being.Here I detail the effects of the abiotic/captive environment of an adult wandering spider, Pardosa saltans (Lycosidae) on its behaviour. These studies focused on spiders collected as adults in their natural environment and spiders developed in the laboratory under controlled conditions. Wild-caught spiders were tested either immediately after capture or after being housed for 15 days post-collection. Laboratory reared spiders were kept in different environments: small or large space combined with the presence or absence of litter. Two tests evaluated by sex show the influence of these rearing conditions: an open-field test and a radial-arm maze test. The results show that wild caught spiders of both sexes tested immediately after capture weighed significantly less and were significantly more active than spiders housed in the laboratory for 15 days and spiders reared in the laboratory. Laboratory conditions induced a positive impact on body mass and negative impact on behaviour activities. The locomotor and exploratory activities of spiders of both sexes kept in container without substrate showed lower. My results suggest that the physical enrichment of the environment can reduce these negative effects for females, but not for males that seem to be more affected by being reared under controlled conditions.

The Effects of Different Undergrowth Vegetation on the Types and Densities of Functional Ground-Dwelling Arthropods in Citrus Orchards

&lt;p&gt;In agricultural lands, citrus orchards, pest feeding and weed seed predation by ground-dwelling arthropods are essential ecosystem services. This research aims to investigate the effects of different undergrowth vegetation, including weed area, bare land, rattail fescue and white clover fields, on the types and densities of functional ground-dwelling arthropods in citrus orchards, using pitfall traps. The captured organisms included carnivorous beetles (&lt;em&gt;Pheropsophus jessoensis&lt;/em&gt;,&lt;em&gt; Chlaenius naeviger&lt;/em&gt; and &lt;em&gt;Dolichus halensis&lt;/em&gt;), wolf spiders (&lt;em&gt;Lycosidae&lt;/em&gt; sp.), earwigs (&lt;em&gt;Anisolabididae&lt;/em&gt; sp.), house centipedes (&lt;em&gt;Scutigeromorpha&lt;/em&gt; sp.), herbivorous ground beetles (&lt;em&gt;Amara&lt;/em&gt; sp., &lt;em&gt;Harpalinae&lt;/em&gt; sp.), crickets and millipedes. Furthermore, the population of the functional ground-dwelling arthropods was significantly increased by the presence of a live mulch, where a higher number was seen in the rattail fescue or white clover compared to the weed or bare land fields. The cover crops also affected the types of arthropods identified, with the rattail fescue field including more &lt;em&gt;Pheropsophus jessoensis&lt;/em&gt; while the white clover had an elevated number of wolf spiders, earwigs and &lt;em&gt;Amara sp. &lt;/em&gt;(a weed seed predator). This discovery indicates that the type of undergrowth vegetation plays an important role in enhancing functional biodiversity. The kind of pests and weeds that these arthropods are effective against, as well as the extent to which their densities can be decreased, is also unknown. Therefore, further research on the feeding habit and predation of these arthropods should be conducted.&lt;/p&gt;

Relationship between beach morphodynamics and body traits in a sand-dwelling wolf spider

Sandy beach macrofaunal communities are mainly structured by the independent response of species to the harsh physical environment. The theoretical framework for sandy beach ecology has been mainly developed on the basis of the outstanding role of morphodynamic factors on resident fauna in this narrow land-sea interface. In the case of supralittoral species, the habitat safety hypothesis (HSH) predicts an increase in body size and weight (among several individual and population attributes) from dissipative beaches (fine sand, gentle slope) to reflective beaches (coarse sand, steep slope). Spiders are relevant components of coastal ecosystems due to their strict dependence on prey availability and their carnivore condition; however, the HSH has never before been tested in this taxonomic group. We studied the relationship between beach morphodynamics and body size, weight and body condition of the wolf spider Allocosa marindia. We performed simultaneous collections of adults of A. marindia in two contiguous estuarine beaches with contrasting morphodynamics. As males were scarce, we measured and weighed only females. In agreement with predictions of the HSH, individuals were larger and heavier at the reflective beach. Individual size, weight and body condition were higher at the beginning of the reproductive period. Reflective beaches would act as more benign environments, providing secure microhabitats for the individuals and their potential prey, while affecting positively body traits during development. Our results provide the first formal testing of the HSH in a sand-dwelling spider on beaches with contrasting morphodynamics.

Transmission of nanoplastics from Culex quinquefasciatus to Pardosa pseudoannulata and its impact on predators

Many studies have explored the effects of plastic particles on aquatic organisms. To date, however, few studies have reported on the effects of plastic particles on terrestrial invertebrates. Here, Culex quinquefasciatus (southern house mosquito, prey) and Pardosa pseudoannulata (wolf spider, predator) were used to explore the transmission of nanoplastics (NPs) from aquatic to terrestrial invertebrates and to verify the effects of NPs in prey on predators. Mosquito larvae were exposed to 0, 200, and 1000 NPs mL−1 polystyrene, respectively, and then fed to spiders when they matured. Results showed that ingestion of NP-exposed mosquitoes affected the growth, development, and behavior of P. pseudoannulata, and the intestinal tissue structure, intestinal flora composition, and related enzymatic activities were also impacted. These results indicate that after spiders ingested NP-exposed mosquitoes, their growth, development, and predation ability were affected. This may prolong time to maturation and decrease the ability of spiders to survive and reproduce in the environment. Thus, plastic particles likely have a wide range of effects on organisms as well as the whole ecosystem.

Landmark‐guided T‐maze learning in the wolf spiderTigrosa helluo

AbstractSpatial learning and navigation may be acquired through idiothetic information (i.e., self‐referential movement cues) or allothetic cues (e.g., external landmarks). Animals may use specific types of landmarks to navigate known as reference frames. A reference frame is an environmental shape or boundary that provides a framework for spatial localization. Wolf spiders produce draglines of silk as they move through the environment that could serve as reference frames and may predispose spiders to use other reference frames to navigate. Using a modified water T‐maze, we recorded the ability of adult femaleTigrosa helluowolf spiders to correctly navigate toward a target goal. We measured variation in spatial learning of the target location with and without a reference frame landmark (tape marking the correct path). Females were trained over ten consecutive trials to successfully achieve the goal. Training trials were then repeated the following day for each subject for a total of 20 trials over two days. In the landmark condition, after the 20 trials, we reversed the reference frame to the incorrect arm choice to test for a decline in performance. For each trial, we measured the latency to achieve the goal and number of reversions or path retracing. Results indicate significantly shorter time to goal over subsequent trials with shorter mean latency to achieve the goal on the second day compared with the first. The landmark treatment showed significantly fewer wrong turns and path retracings than the control, and the reversal of the reference frame significantly increased the latency to achieve the goal. Wolf spiders can learn simple T‐maze navigation under our testing conditions, but learning is enhanced when reference frames are present. Landmarks are important for spider allothetic spatial navigation, and learned spatial navigation tasks are better retained over two days in the presence of reference frames.

Herbivore-Induced Rice Volatiles Attract and Affect the Predation Ability of the Wolf Spiders, Pirata subpiraticus and Pardosa pseudoannulata.

Simple SummaryThe spiders, Pirata subpiraticus Bösenberg et Strand (Araneae: Lycosidae) and Pardosa pseudoannulata Bösenberg et Strand (Araneae: Lycosidae) are important natural enemies of many rice pests. Herbivore-induced plant volatiles can attract natural enemies to pest locations and are becoming important in integrated pest management. This study assessed the effects of herbivore-induced rice volatiles on the selection behavior, predation ability and field attraction of two species of spiders. The selection frequency of spiders for methyl salicylate, linalool, and 2-heptanone were significantly greater than the blank group. Methyl salicylate can shorten the predatory latency of male P. pseudoannulata and can also trap more P. pseudoannulata in the field. Linalool may also shorten the predatory latency of male P. subpiraticus and increase the daily predation capacity of female P. pseudoannulata. In summary, herbivore-induced rice volatiles attract P. pseudoannulata and P. subpiraticus, and potentially increase their pest control capability. These results provide support for the practical use of herbivore-induced rice volatiles to attract and retain spiders in rice fields.Spiders are important natural enemies of rice pests. Studying the effects of herbivore-induced rice volatiles on spider attraction and predation ability may lead to safer methods for pest prevention and control. In this study, four-arm olfactometer, predation ability experiment, and field trapping experiment were used to evaluate the effects of herbivore-induced rice volatiles on Pirata subpiraticus Bösenberg et Strand (Araneae: Lycosidae) and Pardosa pseudoannulata Bösenberg et Strand (Araneae: Lycosidae). The 0.5 μg/μL linalool concentration was attractive, and also shortened the predation latency in male P. subpiraticus and female P. pseudoannulata. The 0.5 μg/μL linalool concentration increased the daily predation capacity of female P. pseudoannulata. Male P. pseudoannulata were attracted to 1.0 g/L methyl salicylate, which also shortened their predation latency. In field experiments, methyl salicylate and linalool were effective for trapping spiders. Herbivore-induced rice volatiles attract rice field spiders and affect their predatory ability. These results suggest that herbivore-induced rice volatiles can be used to attract spiders and provide improved control of rice pests.

Comparative analysis of cadmium-induced toxicity and survival responses in the wolf spider Pirata subpiraticus under low-temperature treatment.

Cadmium (Cd) pollution is a serious heavy metal pollution in paddy fields, but its effect and underlying mechanism on soil arthropod overwintering and cold resistance are still unclear. In the present study, adult females of the wolf spider Pirata subpiraticus exposed to Cd stress underwent a simulated temperature process (25℃ → 16℃ → 8℃ → 4℃). The mortality rate and content of nutrients in the Cd-treated spiders were dramatically elevated after low-temperature treatment compared to those in the Cd-free control spiders under the same temperature condition. To uncover the putative modulatory mechanism of Cd on cold tolerance in P. subpiraticus, we employed an in-depth RNA sequencing analysis and yielded a total of 888 differentially expressed genes (DEGs). Besides, we characterized genes that participate in multiple cryoprotectant syntheses, including arginine, cysteine, glucose, glycerol, heat shock protein, and mannose. The enrichment analyses found that most of the DEGs involved in biological processes and pathways were related to carbohydrate, lipid, and protein metabolism. Notably, ten Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as starch and sucrose metabolism, arachidonic acid metabolism, amino acid metabolism, mineral absorption, and vitamin digestion and absorption, were distinctively enriched with downregulated genes. Meanwhile, we also identified that seven DEGs might inhibit the KEGG pathway of ovarian steroidogenesis and potentially cripple ovarian function and fecundity in the spider. The decreased egg sac weight, number of hatched spiderlings, and vitellin concentration further supported the view that Cd exposure vitiates the overwintering spider's fecundity. Collectively, the comparative analysis provides a novel perspective regarding the survival response and fecundity on the cold tolerance of spiders under Cd stress and offers a profound insight for evaluating Cd-induced toxicity on overwintering arthropods.

Phylogeny and secondary sexual trait evolution in Schizocosa wolf spiders (Araneae, Lycosidae) shows evidence for multiple gains and losses of ornamentation and species delimitation uncertainty

Members of the Nearctic spider genus Schizocosa Chamberlin, 1904 have garnered much attention in behavioral studies and over many decades, a number of species have developed as model systems for investigating patterns of sexual selection and multimodal communication. Many of these studies have employed a comparative approach using putative, but not rigorously tested, sister species pairs that have distinctive morphological traits and attendant behaviors. Despite past emphasis on the efficacy of these presumably comparative-based studies of closely related species, generating a robust phylogenetic hypothesis for Schizocosa has been an ongoing challenge. Here, we apply a phylogenomic approach using anchored hybrid enrichment to generate a data set comprising over 400 loci representing a comprehensive taxonomic sample of 23 Nearctic Schizocosa. Our sampling also includes numerous outgroup lycosid genera that allow for a robust evaluation of genus monophyly. Based on analyses using concatenation and coalescent-based methods, we recover a well-supported phylogeny that infers the following: 1) The New World Schizocosa do not form a monophyletic group; 2) Previous hypotheses of North American species require reconsideration along with the composition of species groups; 3) Multiple longstanding model species are not genealogically exclusive and thus are not “good” species; 4) This updated phylogenetic framework establishes a new working paradigm for studying the evolution of characters associated with reproductive communication and mating. Ancestral character state reconstructions show a complex pattern of homoplasy that has likely obfuscated previous attempts to reconstruct relationships and delimit species. Important characters presumably related to sexual selection, such as foreleg pigmentation and dense bristle formation, have undergone repeated gain and loss events, many of which have led to increased morphological divergence between sister-species. Evaluation of these traits in a comparative framework illuminates how sexual selection and natural selection influence character evolution and provides a model for future studies of multimodal communication evolution and function.

Characterization of Cuticular Proteins in Cpr Family in the Wolf Spider, Pardosa Pseudoannulata, and the Response of One Subfamily Genes to Environmental Stresses

Characterization of Cuticular Proteins in Cpr Family in the Wolf Spider, Pardosa Pseudoannulata, and the Response of One Subfamily Genes to Environmental Stresses

Nutritional symbionts enhance structural defence against predation and fungal infection in a grain pest beetle.

ABSTRACTMany insects benefit from bacterial symbionts that provide essential nutrients and thereby extend the hosts’ adaptive potential and their ability to cope with challenging environments. However, the implications of nutritional symbioses for the hosts’ defence against natural enemies remain largely unstudied. Here, we investigated whether the cuticle-enhancing nutritional symbiosis of the saw-toothed grain beetle Oryzaephilus surinamensis confers protection against predation and fungal infection. We exposed age-defined symbiotic and symbiont-depleted (aposymbiotic) beetles to two antagonists that must actively penetrate the cuticle for a successful attack: wolf spiders (Lycosidae) and the fungal entomopathogen Beauveria bassiana. While young beetles suffered from high predation and fungal infection rates regardless of symbiont presence, symbiotic beetles were able to escape this period of vulnerability and reach high survival probabilities significantly faster than aposymbiotic beetles. To understand the mechanistic basis of these differences, we conducted a time-series analysis of cuticle development in symbiotic and aposymbiotic beetles by measuring cuticular melanisation and thickness. The results reveal that the symbionts accelerate their host's cuticle formation and thereby enable it to quickly reach a cuticle quality threshold that confers structural protection against predation and fungal infection. Considering the widespread occurrence of cuticle enhancement via symbiont-mediated tyrosine supplementation in beetles and other insects, our findings demonstrate how nutritional symbioses can have important ecological implications reaching beyond the immediate nutrient-provisioning benefits.