Search

Female‐biased sexual size dimorphism stands as a widespread evolutionary pattern. Fecundity selection, favouring larger females with greater reproductive output, is a leading explanation. However, larger body sizes demand greater energy intake, potentially hindering the evolution of extreme female sizes. Thus, the evolution of more lucrative foraging tactics may allow for an increase in size. Hence, coupled with selection against larger males, fecundity selection should result in larger SSD in species with more lucrative foraging strategies. Crab spiders are sit‐and‐wait predators that hunt in several plant substrata. Species that forage on flowers or employ prey‐luring strategies likely have access to higher food intake than other species. We extracted body size measurements of 614 crab spider species from 43 genera and classified them based on their foraging strategy. Our findings show that foraging strategies that provide higher energy input (EFS) result in larger SSD. Statistical estimates indicate that females have a cephalothorax width 91% larger than males in EFS species, compared to 26% larger females than males in non‐EFS species. These differences possibly arise due to larger females and smaller males. The effects on male size reduction might result from scramble competition, whereas the increase in female size is likely due to fecundity selection. These results suggest that the shift towards more lucrative foraging strategies may have been a key event in body size and SSD evolution in crab spiders. [ABSTRACT FROM AUTHOR]

Many studies have explored the potential of companion plants to manage pests through top–down or bottom–up effects in agricultural fields. Buckwheat is known as a good candidate for companion planting with various crops to enhance pest management, but rarely in soybeans.We investigated the impact of planting buckwheat as a new companion plant on the population dynamics of major soybean pests and their natural enemies in soybean fields in Andong, Republic of Korea. We recorded numbers of pests and natural enemies at 9–10‐day intervals from 20 soybean plants each in eight small experimental fields throughout the cropping season.Significant reduction in pests, such as Riptortus pedestris (F.) (Hemiptera: Alydidae) adults, and a significant increase in natural enemies, such as Orius species (Hemiptera: Anthocoridae) and crab spiders (Araneae: Thomisidae), were observed in the buckwheat treatment plots. However, there were significant increases in other pests, such as leafminers and leafhoppers, in the buckwheat treatment plots. While we observed effects on R. pedestris adult density, we did not find significant effects on other developmental stages of this pest or its parasitoids.Although there were some concerns in the buckwheat treatment plots, the positive effects of buckwheat in soybean fields appear to outweigh the drawbacks. Buckwheat is likely a suitable companion plant for use in soybeans to manage pests. [ABSTRACT FROM AUTHOR]

Predation exerts a profound influence on the evolution of camouflage and detection abilities in both predators and prey. For instance, flower‐visiting spiders need to ensure their concealment when ambushing on flowers, which compels pollinators to check any spider cues cautiously before landing. Although numerous studies have examined the visual camouflage of spiders deceiving bees, little is known regarding whether spiders also employ olfactory camouflage. Additionally, the detection of spiders by dipteran insects is often overlooked, despite them being major non‐bee pollinators. Here, we explored the detection ability of dipteran pollinators and the crypsis skill of spiders from both olfactory and vision perspectives using the housefly Musca domestica L. (Diptera: Muscidae) as prey, the crab spider Ebrechtella tricuspidata (Fabricius) (Araneae: Thomisidae) as predators and chamomile Matricaria recutita L. (Asteraceae) as substrates. Our olfactory experiments revealed that experienced houseflies could respond to and avoid spider odour. However, this response did not appear to be innate, as naive individuals showed no aversion. Moreover, experienced houseflies did not have any avoidance behaviours to the mixed odours of spider and flower, indicating that spiders achieved olfactory crypsis utilizing floral scent. Our vision experiments and visual modelling demonstrated that houseflies could detect spiders positioned on flower. Surprisingly, instead of avoiding them, houseflies exhibited a preference for flowers occupied by female spiders, suggesting the attractive nature of female spider colouration. This paper provides evidence for the first time that crab spiders use floral scent to achieve olfactory crypsis and proposes a potential yellow‐signalling mechanism for crab spiders to attract insects. [ABSTRACT FROM AUTHOR]

The species Xysticus lendli is known only from its original description of a single male and one doubtful record so far. Here, we illustrate and redescribe the species based on 34 specimens in total and describe its female for the first time. We illustrated the male palp via compound micrographs and scanning electron micrographs. We generated a DNA barcode and placed it into a current phylogenetic scaffold to confirm the species' placement of Spiracme, a long-debated sister- or subgroup of Xysticus; hence, a new combination of Spiracme lendli (Kulczyński, 1897), comb. nov. is proposed. We illustrated the visually similar Xysticus mongolicus and the type species of Spiracme, S. striatipes, and compared them to S. lendli to aid future distinctions between those species. [ABSTRACT FROM AUTHOR]

Changes in leaf phenology from warming spring and autumn temperatures have lengthened the temperate zone growing "green" season and breeding window for migratory birds in North America. However, the fitness benefits of an extended breeding season will depend, in part, on whether species have sufficient dietary flexibility to accommodate seasonal changes in prey availability. We used fecal DNA metabarcoding to test the hypothesis that seasonal changes in the diets of the insectivorous, migratory black‐throated blue warbler (Setophaga caerulescens) track changes in the availability of arthropod prey at the Hubbard Brook Experimental Forest, New Hampshire, USA. We examined changes across the breeding season and along an elevation gradient encompassing a 2‐week difference in green season length. From 98 fecal samples, we identified 395 taxa from 17 arthropod orders; 242 were identified to species, with Cecrita guttivitta (saddled prominent moth), Theridion frondeum (eastern long‐legged cobweaver), and Philodromus rufus (white‐striped running crab spider) occurring at the highest frequency. We found significant differences in diet composition between survey periods and weak differences among elevation zones. Variance in diet composition was highest late in the season, and diet richness and diversity were highest early in the season. Diet composition was associated with changes in prey availability surveyed over the green season. However, several taxa occurred in diets more or less than expected relative to their frequency of occurrence from survey data, suggesting that prey selection or avoidance sometimes accompanies opportunistic foraging. This study demonstrates that black‐throated blue warblers exhibit diet flexibility and track seasonal changes in prey availability, which has implications for migratory bird responses to climate‐induced changes in insect communities with longer green seasons. [ABSTRACT FROM AUTHOR]

Since its introduction into Seattle, King County, Washington, prior to 1952, the European thomisid Ozyptila praticola (C. L. Koch, 1837) has spread throughout the eastern Puget Lowlands to inhabit an area of over 1300 sq mi (3400 sq km) centered in western King and Snohomish Counties. A separate population of O. praticola was also found in western Whatcom Co. that may be linked to the O. praticola population in Metro Vancouver, British Columbia, Canada. Ozyptila praticola was eudominant (> 10% abundance) in 86% of fallen conifer cone, 69% of moss, and 55% of litter samples. It was largely found in anthropogenically disturbed habitats, with some invasion into forests adjacent to development. Females, penultimates, and a consistent size-range of pre-penultimate juveniles were present year-round. Males were found mainly in spring and fall. Ozyptila praticola may be expected to continue increasing its range in anthropogenic and adjacent habitats in western Washington. [ABSTRACT FROM AUTHOR]

We present new records and species of running crab spiders (family Philodromidae) from Colombia representing four genera: Apollophanes O. Pickard-Cambridge, 1898, GephyrellulaStrand, 1932, PetrichusSimon, 1886, and Tibelloides Mello-Leitão, 1939. The genus Gephyrellula is recorded based on the newly described G. lavidabonitasp. nov., known from females from the department of Magdalena, constituting the northernmost known locality for the genus, at Sierra Nevada de Santa Marta. This new species can be differentiated from the (previously monotypic) type species G. violacea (Mello-Leitão, 1918), known from southeastern region of Brazil, by the longer than wide epiginal plates (wider than long in G. violacea), with narrower and shorter ducts of the glandular heads (thicker and longer in G. violacea), and by their more posteriorly placed fertilization ducts. The genus Apollophanes is here firstly recorded from males and females of A. punctipes (O. Pickard-Cambridge, 1891) from the Atlántico, Magdalena, Cesar, Cundinamarca, and Boyacá departments. Tibelloides is recorded from males and females of T. bryantae (Gertsch, 1933), from the departments of Magdalena and Meta, also representing northernmost known localities for the genus. Finally, new faunistic and taxonomic data is presented for Petrichus. Our examination of the holotype of Thanatus granadensisKeyserling, 1880 demonstrates this species is conspecific with more recently collected and better-preserved specimens of Petrichus griseusBerland, 1913, from the department of Santander. Therefore, we propose the new combination Petrichus granadensiscomb. nov., regard P. griseus as its junior synonym syn. nov., and update knowledge of its distribution. [ABSTRACT FROM AUTHOR]

In Italy, the selenopid spider Selenops radiatus Latreille, 1819, was hitherto only known from the Aeolian Archipelago (northeastern Sicily), with a record from the island of Alicudi and plausible sightings from the island of Filicudi. In this paper, we present twentysix new records from Sicily sensu stricto and its satellite islands, consisting of observations gathered from online naturalist networks and one adult specimen collected from the area where most observations were made. Nearly all records were made in buildings or similar artificial habitats, supporting the hypothesis that occurrences of S. radiatus are mainly limited to synanthropic environments in Sicily. [ABSTRACT FROM AUTHOR]

The meadow spittlebug Philaenus spumarius L. (Hemiptera: Aphrophoridae) is a xylem‐sap feeder and the most abundant and widespread vector of Xylella fastidiosa (Xanthomonadales: Xanthomonadaceae) throughout Europe. Control strategies for the disease are based on containment and eradication measures regulated by the European Union. Within the context of biological control, the use of natural enemies aims at limiting the insect vector population in agroecosystems. Spiders are generalist predators with potential as biological control agents occupying all the habitats within crops. Crab spiders (Thomisidae) could be potential natural enemies against P. spumarius. The functional response (FR) of a predator represents the intake rate as a function of food availability and allows estimating feeding behaviour parameters such as the prey handling time and attack rate. However, spiders often kill more prey than they consume, unveiling their capacity as natural enemies. We assessed and compared the FR of Xysticus acerbus (Thomisidae) fed on P. spumarius in the laboratory considering (1) the total number of dead individuals and (2) only the consumed ones. We found that although both FRs were of type‐II, they significantly differed. The values of attack rate and handling time for consumed were 0.1 and 3.6, respectively, while for dead, the attack rate was 0.3 and 1.1, being both significantly different. Moreover, the number of overkilled individuals reached a plateau at the highest prey densities. Xysticus acerbus could be a potential natural enemy of P. spumarius. Nevertheless, we suggest that the effect of including the killed but not consumed prey individuals in FR studies using wasteful killing predators should be considered and further studied. [ABSTRACT FROM AUTHOR]

Ecological restoration often targets plant community recovery, but restoration success may depend on the recovery of a complex web of biotic interactions to maintain biodiversity and promote ecosystem services. Specifically, management that drives resource availability, such as seeding richness and provenance, may alter species interactions across multiple trophic levels. Using experimentally seeded prairies, we examine three key groups—plants, pollinators and goldenrod crab spiders (Misumena vatia, predators of pollinators)—to understand the effects of species richness and admixture seed sourcing of restoration seed mixtures on multitrophic interactions.Working with prairie plants, we experimentally manipulated seed mix richness and the number of seed source regions (single‐source region or admixture seed sourcing). In each experimental prairie, we surveyed floral abundance and richness, pollinator visitation and plant–M. vatia interactions.A high richness seed mix increased floral abundance when seeds were sourced from a single geographic region, and floral abundance strongly increased pollinator visitation, M. vatia abundance and prey capture. Seeding richness and admixture seed sourcing of the seed mixture did not affect floral species richness, but floral species richness increased pollinator visitation.Pollinators interacted with different floral communities across seeding treatments, indicating a shift in visited floral species with restoration practices.Synthesis and applications. Long‐term success in prairie restoration requires the restoration of plant–arthropod interactions. We provide evidence that seed mix richness and admixture seed sourcing affect arthropod floral associations, but effective restoration of plant–arthropod interactions should consider total floral resource availability. Incorporating a food web perspective in restoration will strengthen approaches to whole ecosystem restoration. [ABSTRACT FROM AUTHOR]

Xysticus cristatus is a Palearctic species, very abundant in the north-western Himalayas having a temperate climate. It is one of the predominant species in the agroecosystems of Kashmir. For a period of two years, we conducted a study on the population of Xysticus cristatus inhabiting the agroecosystems of Kashmir. A phenological study was conducted under field and laboratory conditions and temperature, rainfall, and humidity were monitored as indicators of population size. The spiders appear to have an annual reproductive cycle and a spring–summer stenochronous phenological pattern. Adult spiders emerge in spring, recruitment of spiders occurs in summer, they undergo overwintering in the immature stage and all stages of development show sequential phenological maxima. Under laboratory conditions, almost all spiders took VII instars to develop, and considerable variations were observed among all the instars. The abundance of Xysticus cristatus did not show any correlation with climatic variables at time 0, although there was a correlation with temporal lag. The best-adjusted correlation was found with a 3 month time lag, indicating that species require time to respond to changes in the environment. [ABSTRACT FROM AUTHOR]

Taxonomic notes on the Talaus species from China are provided. Two new species, T. yuyang Yao & Liu, sp. nov. and T. zhangjiangkou Yao & Liu, sp. nov. are described and illustrated, and a further three species are redescribed based on their genitalic characters: T. dulongjiang Tang, Yin, Ubick & Peng, 2008, T. niger Tang, Yin, Ubick & Peng, 2008, and T. sulcus Tang & Li, 2010. The species T. xiphosus Zhu & Ono, 2007 is considered a junior synonym of T. triangulifer Simon, 1886 based on an examination of many recently collected female and male specimens from Guangxi Province, China. Diagnoses, detailed illustrations and a map of distributional records of the six treated species of Talaus in China are provided. [ABSTRACT FROM AUTHOR]

Two species assigned to Massuria Thorell, 1887 are reviewed. The female of Massuria bandian Tang & Li, 2010 is described for the first time from Jianfengling National Natural Reserve, Hainan Province, China. The species Diaea simplex Xu, Han & Li, 2008 is described as a synonym of Massuria bellula Xu, Han & Li, 2008 based on female and male specimens from Guangdong Province, China. Massuria min sp. nov. described as a new species (female, Fujian Province, China). Detailed illustrations and a distribution map are provided for these three species of Massuria. [ABSTRACT FROM AUTHOR]

The thomisid spider Synema globosum (Fabricius, 1775) is widely distributed in the Palaearctic realm and is particularly common in southern parts of zones with a temperate climate. Seven subspecies have been described; the widely distributed nominotypical subspecies, S. g. globosum and six with much more restricted ranges. As of now, just two subspecies are still recognised as valid while the others have been synonymized with the nominate subspecies. This study now revalidates S. g. canariense Dahl, 1907 (subsp. reval.) based on findings from molecular and comparative morphological analysis. We also argue that the synonymization of the subspecies S. g. daghestanicum Utochkin, 1960 and the species S. japonicum Karsch, 1879 with S. globosum in Ono (1988) is formally correct, but needs further investigation with modern methods. [ABSTRACT FROM AUTHOR]

We describe a new species of giant crab spider of the genus Sadala Simon, 1880 collected in Lowland Evergreen rainforests at the Tiputini Biodiversity Station, Yasuni Biosphere Reserve, Amazonian Ecuador. This new species corresponds to the first record of the genus from Ecuador. Females of the new species of Sadala are similar to S. punicea and S. nanay, by having the epigyne with a median septum diamond‐shaped posteriorly. The new species is easily distinguished from S. punicea and S. nanay by having relatively straight anterior lateral margins of the median septum. This study increases to 10 the number of described species of Sadala. [ABSTRACT FROM AUTHOR]

Spiders have become a model group for sexual selection and mating system studies, but our understanding of courtship behavior in the group is heavily biased towards the infraorder Araneomorphae ('modern' spiders, such as orb weavers, jumping spiders, wolf spiders, crab spiders and many more). In the Mygalomorphae (tarantulas, trapdoor spiders, funnel‐web spiders and relatives), only a few descriptions of courtship are available and recent developments in the phylogenetics of the group offer an opportunity to remap and investigate the evolution of mating behaviors. Using 81 trials filmed in captivity, we report on the courtship behaviors of the iconic Sydney funnel‐web spider (Atracidae: Atrax robustus), which belongs to a large clade of biologically understudied mygalomorphs. Thirteen distinct behaviors are described for males, out of which at least two seem new to mygalomorphs, while four female behaviors are described. Moreover, the sequences of male behaviors are presented for when they come into contact with females inside or outside of their burrows. The mating positions of the pair, including details of how males use their legs and clasping spurs to grasp the females, are also presented. We discuss our results in a modern phylogenetic context, filling a gap in the understanding of sexual selection in the Mygalomorphae where such studies are rare and biased towards tarantulas. Finally, we attempt to consolidate descriptions of potentially homologous behaviors from several families in the group and offer insights into the evolution of cannibalism, male clasping spurs and female catalepsis (quiescence while mating). [ABSTRACT FROM AUTHOR]

Two new species of crab spider are described from the Xiaolong Mountains in Gansu Province, China: Ebelingia spirala sp. nov. (♂♀) and Lysiteles longensis sp. nov. (♂♀). Detailed morphological characters, a distribution map, photographs, and illustrations of the habitus and copulatory organs are given for each species. [ABSTRACT FROM AUTHOR]

They mostly come at night: Predation on sleeping insects by introduced candy-striped spiders in North America We rarely observed candy-striped spiders invading other spiders' webs to engage in kleptoparasitism or araneophagy. gl In North America, candy-striped spiders often occur in very high densities (e.g., Tomascik, [13]), and they thrive in a variety of habitats, suggesting that they may have strong impacts on insect communities. Keywords: Enoplognatha latimana; Enoplognatha ovata; foraging ecology; insect sleep; natural history; predation behavior EN Enoplognatha latimana Enoplognatha ovata foraging ecology insect sleep natural history predation behavior 1 6 6 05/03/23 20230501 NES 230501 Candy-striped spiders (two closely related and nearly indistinguishable species: I Enoplognatha ovata i (Clerck, 1757) and I Enoplognatha latimana i Hippa & Oksala, [8]) are, at first glance, unremarkable cobweb weavers in the family Theridiidae. We have also observed candy-striped spiders invading the webs of other spiders to steal prey, consume the host spiders, and/or take over the web and hunt on it (Figure 2c,d, Appendix S1: Table S2). [Extracted from the article]

This short paper reports a thomisid species which is new for the Turkish araneofauna. The characteristic features and photographs of Ozyptila rigida (O. Pickard-Cambridge, 1872) are presented in addition to its distribution map. [ABSTRACT FROM AUTHOR]

A fragmented landscape, which contains a patchwork of vegetated hospitable areas and a barren intervening matrix, may reduce gene flow in a population and over time result in an increase in population structure.We tested this prediction in crab spiders (Mecaphesa celer (Hentz, 1847)) inhabiting isolated habitat patches in the lava matrix of Craters of the Moon National Monument and Preserve, Idaho, USA.Using reduced‐representation genomic sequencing, we did not find evidence of population structure due to a reduction in gene flow among habitat patches.Instead, our results show strong evidence of panmixia likely due to abundant juvenile dispersal and possible connectivity to outer regions surrounding the lava flows despite the species' habitat specificity. [ABSTRACT FROM AUTHOR]

Heriaeus buffoni (Audouin, 1826) is reported for the first time from the Canary Islands, where it was found on Lanzarote. This also represents the first record of the genus in the archipelago. All individuals were collected with pitfall traps installed in nitrophilous synanthropic shrub vegetation near urban areas. Species identification was based on male genitalia only as females were not sampled. A map including all known records from Lanzarote, drawings of the pedipalps and photographs of living and preserved specimens are presented. [ABSTRACT FROM AUTHOR]

In aggressive mimicry, a predator accesses prey by mimicking the appearance and/or behavior of a harmless or beneficial model in order to avoid being correctly identified by its prey. The crab spider genus Phrynarachne is often cited as a textbook example of masquerading as bird droppings (BDs) in order to avoid predation. However, Phrynarachne spiders may also aggressively mimic BDs in order to deceive potential prey. To date, there is no experimental evidence to support aggressive mimicry in masquerading crab spiders; therefore, we performed a field survey, a manipulative field experiment, and visual modeling to test this hypothesis using Phrynarachne ceylonica. We compared prey-attraction rates among BDs, spiders, and control empty leaves in the field. We found that although all prey combined and agromyzid dipterans, in particular, were attracted to BDs at a higher rate than to spiders, other dipterans and hymenopterans were attracted to BDs at a similar rate as to spiders. Both spiders and BDs attracted insects at a significantly higher rate than did control leaves. As predicted, prey was attracted to experimentally blackened or whitened spiders significantly less frequently than to unmanipulated spiders. Finally, visual modeling suggested that spiders and BDs can be detected by dipterans and hymenopterans against background leaves, but they are indistinguishable from each other. Taken together, our results suggest that insects lured by spiders may misidentify them as BDs, and bird-dropping masquerading may serve as aggressive mimicry in addition to predator avoidance in P. ceylonica. [ABSTRACT FROM AUTHOR]

Philodromus poecilus (Thorell, 1872) is a Transeurasian species reported from most parts of Europe except the British Isles and the Iberian Peninsula. Although widely distributed, this species is extremely rarely recorded in Germany and neighbouring countries. In Bavaria, it has not been found since the time of Ludwig Koch (1825-1908). Recently, several specimens were collected from urban plane trees in Deggendorf (Lower Bavaria), proving that the species is still present in Bavaria. Additionally, images of the copulatory organs and of living and preserved specimens are presented, as is a compilation of records in Germany and neighbouring countries. [ABSTRACT FROM AUTHOR]

A list of 34 thomisid species belonging to 21 genera collected in Jangxi Province of China is provided. Five new species are described: Angaeus xieluae Liu, sp. nov. (♂♀), Lysiteles subspirellus Liu, sp. nov. (♀), Oxytate mucunica Liu, sp. nov. (♀), Pharta lingxiufengica Liu, sp. nov. (♀), Stephanopis xiangzhouica Liu, sp. nov. (♀). A new combination is proposed: Ebelingia forcipata (Song & Zhu, 1993) comb. nov. (ex. Ebrechtella Dahl, 1907). Previously unknown females of E. forcipata (Song & Zhu, 1993), Oxytate bicornis Liu, Liu & Xu, 2017, and Xysticus lesserti Schenkel, 1963 are described for the first time. Stephanopis O Pickard-Cambridge, 1869, a genus previously known from Australasia and South America, is recorded from the Asian mainland for the first time. [ABSTRACT FROM AUTHOR]

Selection imposed by visually hunting predators has driven the evolution of colour‐based antipredator defence strategies such as crypsis, masquerade, mimicry and aposematism. Individuals of many animals are generally considered to rely on a single type of defence strategy, but individuals of some species use multiple colour‐based defences. Many animals switch between colour‐based defences against visually hunting predators during ontogeny. However, why this occurs remains poorly understood.The crab spider Phrynarachne ceylonica is an often‐cited example of a bird dropping masquerade. It has recently been demonstrated that P. ceylonica crab spiders gain protection from their predators by being misidentified as bird droppings by their predators. P. ceylonica females show an ontogenetic shift in colour defences: early instars possess a dark and cryptic form, while at later instars and as adults, the spiders resemble bird droppings. We hypothesised that this shift may be driven by differential changes in predation risk of two defence strategies with increasing body size due to ontogeny.We tested this hypothesis by presenting naïve domestic chicks with 3D printed artificial spiders of two different sizes (small, large) and two colours (dark, bird dropping‐like), and determined whether larger bird dropping‐like spiders are more readily found and attacked than cryptic forms by chicks. We found that small cryptic spiders were more difficult to detect than small bird dropping masquerading spiders, but large cryptic spiders were attacked much more quickly and more frequently than large bird dropping masquerading spiders.Increasing predation pressure on larger, cryptic spiders during ontogeny suggests that switching to bird dropping masquerade may be a more effective defence as spiders increase in size. We thus conclude that the ontogenetic shift from crypsis to masquerade is adaptive. [ABSTRACT FROM AUTHOR]

Grassland insect pollinators have undergone population declines due to habitat loss and degradation. Patch-burning is a management method used to reduce woody plant encroachment and maintain grassland habitats. However, the impacts of fire on the quality and quantity of floral resources (nectar volume, total sugar, and sucrose concentration) available to insect pollinators are understudied. Evaluating how time since last fire and season of fire impact nectar quality and quantity is vital to understanding the overall impact of fire on insect pollinator communities. For this study, 10 flowering forb species (Asclepias viridis, Baptisia alba, Cirsium undulatum, Desmodium canadense, Monarda citriodora, Monarda fistulosa, Oenothera speciosa, Penstemon tubaeflorus, Ruellia humilis, Spiranthes cernua) were selected in The Nature Conservancy's Joseph H. William's Tallgrass Prairie Preserve in an area managed with patch-burning and cattle grazing. Study sites were burned in spring 2018, summer 2018, summer 2019, and spring 2020, with three replicates of each treatment (for 12 total burn units). In each unit, we collected nectar from flowering individuals of each plant species with microcapillary tubes to measure standing crop or the nectar in flowers at any given time that is available to insect pollinators. Total volume of nectar and sucrose concentration were recorded, and total mg of sugar was calculated. Desmodium canadense flowering individuals were only located in units burned the previous spring, whereas P. tubaeflorus flowering individuals were only located in units burned the previous summer. For the eight remaining species, total volume of nectar, total mg of sugar, and sucrose concentration varied with different burn regimens for different species. Cirsium undulatum inflorescences with crab spiders (Thomisidae) had higher volumes of nectar and higher amounts of sugar available. This study highlights how a patch-burn approach with different fire return intervals may benefit insect pollinators at the community level by providing a wide range of nectar qualities and quantities to support insect pollinators with different nutritional needs. [ABSTRACT FROM AUTHOR]

We report the first records of the poorly known crab spider Tmarus longicaudatusMillot, 1942 in Mauritania, Namibia and the United Arab Emirates (UAE). The new record in Mauritania extends the distribution of the species by almost 2750 km to the west from the closest and type locality in Niger. The new record in Namibia is 1000 km north of the closest locality in South Africa. New records in the UAE are more than 900 km east of the closest locality in central Saudi Arabia. Using all available records, we present the known distribution of the species and its climate-based predicted range, indicating a wide distribution in arid to semi-arid regions. Considering its wide expected distribution, extending throughout Africa and the Arabian Peninsula, integrative taxonomic studies are needed to clarify the species status of this masquerading spider. [ABSTRACT FROM AUTHOR]

Establishing species boundaries is one of the challenges taxonomists around the world have been tackling for centuries. The relation between intraspecific and interspecific variability is still under discussion and in many taxa it remains understudied. Here the hypothesis of single versus multiple species of the crab spider Synema globosum (Fabricius) is tested. The wide distribution range as well as its high morphological variability makes this species an interesting candidate for re-evaluation using an integrative approach. This study combines information from barcoding, phylogenetic reconstruction based on mitochondrial CO1 and ITS2 of more than 60 specimens collected over a wide range of European localities, and morphology. The findings show deep clades with up to 6% mean pairwise distance in the CO1 barcode without any biogeographical pattern. The nuclear ITS2 gene did not support the CO1 clades. Morphological assessment of somatic and genital characters in males and females and a morphometric analysis of the male palp uncovered high intraspecific variation that does not match the CO1 or ITS2 phylogenies or biogeography either. Screening for endosymbiotic Wolbachia bacteria was conducted and only a single infected specimen was found. Several scenarios might explain these inconsistent patterns. While the deep divergences in the barcoding marker might suggest cryptic or ongoing speciation or geographical isolation in the past, the lack of congruent variation in the nuclear ITS2 gene or the studied morphological character systems, especially the male palp, indicates that S. globosum might simply be highly polymorphic both in terms of its mtDNA and morphology. Therefore, more data on ecology and behaviour and full genome sequences are necessary to ultimately resolve this taxonomically intriguing case. [ABSTRACT FROM AUTHOR]

The Iraqi spider fauna includes several dozens of species described and reported mostly by local researchers but still there are considerable sampling gaps. For the first time in Iraq, Agelena orientalis C. L. Koch 1837 (Agelenidae), Oxyopes globifer Simon, 1876 (Oxyopidae), and Thanatus formicinus (Clerck, 1757) (Philodromidae) are recorded. In addition, newly collected material of Bassaniodes tristrami (O. Pickard-Cambridge, 1872) (Thomisidae) and Eusparassus mesopotamicus Moradmand & Jäger, 2012 (Sparassidae) are also presented. The characteristic features, habitus and copulatory organs of all species are presented here along with their geographic distribution. [ABSTRACT FROM AUTHOR]

However, the flower visitors differed greatly between day and night; diurnal flower visitors were mainly bees (54.7%), hoverflies (9.0%), and butterflies (34.5%), whereas nocturnal flower visitors were exclusively moths (99.7%; Appendix S1: Table S6). If settling moths can recognize ambush predators on flowers, they should avoid the flowers with predators more frequently than those without predators. Although nocturnal insects such as moths are important pollinators of many flowering plants (Hahn and Brühl 2016), the impact of ambush predators on nocturnal pollinators remains unclear. Keywords: mantis; mantisfly; Mantodea; Neuroptera; pollinators; predation; Scutigeromorpha; settling moths EN mantis mantisfly Mantodea Neuroptera pollinators predation Scutigeromorpha settling moths 1 4 4 11/02/21 20211101 NES 211101 Ambush predators such as spiders affect the flower-visiting behavior of diurnal pollinators such as bees (Dukas 2001, Dukas and Morse 2003), potentially causing diurnal pollinators to avoid flowers where ambush predators wait (Dukas 2001). [Extracted from the article]

Pigment organelles of vertebrates belong to the lysosome-related organelle (LRO) family, of which melanin-producing melanosomes are the prototypes. While their anabolism has been extensively unraveled through the study of melanosomes in skin melanocytes, their catabolism remains poorly known. Here, we tap into the unique ability of crab spiders to reversibly change body coloration to examine the catabolism of their pigment organelles. By combining ultrastructural and metal analyses on high-pressure frozen integuments, we first assess whether pigment organelles of crab spiders belong to the LRO family and second, how their catabolism is intracellularly processed. Using scanning transmission electron microscopy, electron tomography, and nanoscale Synchrotron-based scanning X-ray fluorescence, we show that pigment organelles possess ultrastructural and chemical hallmarks of LROs, including intraluminal vesicles and metal deposits, similar to melanosomes. Monitoring ultrastructural changes during bleaching suggests that the catabolism of pigment organelles involves the degradation and removal of their intraluminal content, possibly through lysosomal mechanisms. In contrast to skin melanosomes, anabolism and catabolism of pigments proceed within the same cell without requiring either cell death or secretion/phagocytosis. Our work hence provides support for the hypothesis that the endolysosomal system is fully functionalized for within-cell turnover of pigments, leading to functional maintenance under adverse conditions and phenotypic plasticity. First formulated for eye melanosomes in the context of human vision, the hypothesis of intracellular turnover of pigments gets unprecedented strong support from pigment organelles of spiders. [ABSTRACT FROM AUTHOR]

The text is a correction notice from the Journal of Arachnology that highlights a study on spiders feeding on vertebrates. The study reveals that this behavior is more common and widespread than previously believed, with approximately 30% of spider families capable of capturing vertebrate prey. The study distinguishes between habitual vertebrate-eaters and occasional vertebrate-eaters, with ten spider families accounting for 91% of reported vertebrate predation incidents. The findings shed light on spider feeding ecology and the significance of vertebrate prey as a food source for spiders. The text also discusses the feeding habits of spiders that prey on vertebrates, categorizing spider families into two groups: habitual vertebrate-eaters and occasional vertebrate-eaters. It mentions the use of prey-catching webs by spiders and their ability to capture vertebrate prey. The document is a compilation of various scientific articles and publications related to spiders feeding on vertebrates, providing a comprehensive overview of the research conducted on this topic. [Extracted from the article]

The poorly known crab spider Ozyptila aculipalpaWunderlich, 1995 (Araneae, Thomisidae) was originally described on the basis of a male specimen from Iran. The species is redescribed here using new specimens collected from Turkey. The previously unknown female of this species is described for the first time. [ABSTRACT FROM AUTHOR]

The first record of the crab spider Epicadus camelinus (O. Pickard-Cambridge, 1869) from Peru is presented. A single female specimen was collected in the Área de Conservación Privada Panguana in 1984 and deposited in the State Museum of Natural History Karlsruhe, Germany. The record represents a considerable range extension of approximately 800 km west of the closest known locality of the species in Brazil. The specimen and the corresponding diagnostic characters are illustrated in detail. [ABSTRACT FROM AUTHOR]

1. Crab spiders (Thomisidae) are common flower‐visiting spiders that ambush prey on inflorescences. As such, they require specific flowers or substrates for hunting, which are most often selected using sensory cues (e.g. vision). However, few studies have examined the visual preference of crab spiders for particular flowers. In this study, the visual preferences of the crab spider Ebrechtella tricuspidata for different inflorescence characteristics (e.g. colour and shape) were investigated. 2. The results showed that adult spiders explored all colours and shapes, whereas juvenile spiders displayed an overall preference for long (red) and short (purple) wavelength colours. Thus, differences in colour were not particularly important for E. tricuspidata with regard to visual attractiveness and selection. 3. However, inflorescence shape (e.g. tulip) was found to be a more desirable trait for selection, which was probably due to the provision of shelter. 4. These results also suggest that male preference for female spiders depended somewhat on the background colour (wavelength) of the flower on which the female was located. [ABSTRACT FROM AUTHOR]

In the present study, I reported that the female adult crab spider Thomisus labefactus preyed on a female adult of the wasp spider Argiope bruennichi in the centre of the web. To my knowledge, the case that a large orb-weaving spider A. bruennichi is fed upon by the crab spiders with web-invading is not known previously. It has been shown that T. labefactus, considered commonly as a sit-and-wait predator, also aggressively hunt A. bruennichi, the large web-building spider, attacking its prey at the centre of web. [ABSTRACT FROM AUTHOR]

Two exotic spider species are reported for the first time in Argentina: Ozyptila praticola (C.L. Koch) (Thomisidae) and Microctenonyx subitaneus (O. Pickard-Cambridge) (Linyphiidae), being the former the first record from the southern hemisphere. The specimens were found in the leaf litter and under tree barks of modified environments in three localities in the southeast coast of Buenos Aires province. We propose the monitoring and study of the ecology of these new spider populations in order to elucidate potential risk for the local fauna. [ABSTRACT FROM AUTHOR]

Habitat destruction and land use intensification are major causes of arthropod decline in agroecosystems. Arthropods are key organisms that are linked to many ecosystem functions and sustainability of agriculture. Using 37 vineyards in Southern France as a model system, we analysed which characteristics of spontaneous inter-row vegetation positively influence beneficial arthropods and pest insect predation. We specifically studied the effects of flower cover, grass cover, the ratio of perennials to annuals, plant species richness and extrafloral nectar on beneficial arthropod communities in vineyards. We used direct observation and net hunting to evaluate arthropod abundance. Sentinel cards with Lucilia sp. larvae were placed on grapevine plants to analyse caterpillar predation. We found that most groups of tested beneficial arthropods were positively influenced by flower cover and plant species richness. In particular, the abundance of predators such as ladybirds (adults and larvae) and crab spiders and the abundance of parasitic wasps were positively correlated to flower cover in vineyard inter-row vegetation. The abundance of ladybirds, hoverflies and crab spiders was also positively related to plant species richness. Our results demonstrated the importance of floral resources and plant diversity for beneficial arthropods and caterpillar predation confirming their key role in biological control of pest insects. • Characteristics of vineyard inter-row vegetation strongly affected beneficial arthropods. • Flower cover had a positive effect on arthropods partially feeding on floral resources such as ladybirds and parasitic wasps. • Crab spiders not feeding on floral resources also benefitted from nectariferous flowers via prey attraction. • Plant species richness favoured beneficial arthropods such as hoverflies, ladybirds and crab spiders. • The positive effect of plant species richness translated in a higher predation of sentinel prey. [ABSTRACT FROM AUTHOR]

Predation is one of the main interactions between organisms and one of the primary selective agents for their survival. Both prey and predators have developed different strategies and characteristics that allow them to be conspicuous or go undetected. In sit and wait predators, their shape and appearance are important factors that allow them to remain undetected by their potential prey. Sit and wait predators such as crab spiders are difficult to identify when they sit on flowers or areas of flowers with colors similar to the color of their bodies. In this study, we aimed to determine if insects can recognize the morphology and color polymorphism of crab spiders by evaluating the response of flower visitors. We quantified the visits and approaches of floral visitors to the flowerheads of Palafoxia lindenii with spider morphology and color polymorphism treatments. Our results show that insects in general, and bees in particular, avoid visiting flowers with a real spider or a spider model and visit vacant flowers more frequently. In the case of the color polymorphism, insects approached flowerheads with spiders with a similar frequency independently of the color of the spiders, but did not visit them. Insects appeared to identify spiders through their morphological characteristics rather than their color characteristics, since flower visitors did not discriminate between the evaluated spider colors (white, lilac, and purple). This study emphasizes the differential response of different insect prey to the presence, color, and morphology of sit and wait predators. [ABSTRACT FROM AUTHOR]