Preliminary Studies on the Zoogeographic Divisions of Chinese Ground Spiders(Araneae:Gnaphosidae)

This paper aims to carry out the preliminary study on the zoogeographic distributions of 166 species within Gnaphosidae by clustering method,and analyze and compare the similarities of 15 subregions in seven zoogeographic regions in China.The results suggested that the division of Northern China was coincident with the distribution pattern of Chinese ground spiders,but there was subregion recombination between the other regions.There was aggregation between Da Hinggan Mountains subregion in the Northeast,east plain subregion in Mengxin area and west hungriness subregion,between Tianshan mountainous subregion in Mengxin area,Qiangtang altiplano subregion and the southwest mountainous region subregion in Southwest,and between east hill plain subregion in central China,west mountainous region altiplano subregion,Min and Guang coastal subregion in south of China and south Dian mountainous region subregion.The other two subregions in the Northeast formed a region.Qinghai and south Xizang subregion in Qinghai-Xizang Region formed a branch independently.

Mitochondrial phylogenomics provides insights into the phylogeny and evolution of spiders(Arthropoda:Araneae)

Spiders are among the most varied terrestrial predators,with highly diverse morphology,ecology,and behavior.Morphological and molecular data have greatly contributed to advances in the phylogeny and evolutionary dynamics of spiders.Here,we performed comprehensive mitochondrial phylogenomics analysis on 78 mitochondrial genomes(mitogenomes)representing 29 families;of these,23 species from eight families were newly generated.Mesothelae retained the same gene arrangement as the arthropod ancestor(Limulus polyphemus),while Opisthothelae showed extensive rearrangement,with 12 rearrangement types in transfer RNAs(tRNAs)and control region.Most spider tRNAs were extremely truncated and lacked typical dihydrouridine or TΨC arms,showing high tRNA structural diversity;in particular,trnS1 exhibited anticodon diversity across the phylogeny.The evolutionary rates of mitochondrial genes were potentially associated with gene rearrangement or truncated tRNAs.Both mitogenomic sequences and rearrangements possessed phylogenetic characteristics,providing a robust backbone for spider phylogeny,as previously reported.The monophyly of suborder,infraorder,retrolateral tibial apophysis clade,and families(except for Pisauridae)was separately supported,and high-level relationships were resolved as(Mesothelae,(Mygalomorphae,(Entelegynae,(Synspermiata,Hypochilidae)))).The phylogenetic positions of several families were also resolved(e.g.,Eresidae,Oecobiidae and Titanoecidae).Two reconstructions of ancestral web type obtained almost identical results,indicating that the common ancestor of spiders likely foraged using a silk-lined burrow.This study,the largest mitochondrial phylogenomics analysis of spiders to date,highlights the usefulness of mitogenomic data not only for providing efficient phylogenetic signals for spider phylogeny,but also for characterizing trait diversification in spider evolution.

The Predatory Function of Three Spiders to Two Insect Pests in Rice Within a Multi-species Co-existence System

The prey-seeking behavior of three spiders (X1-Pirata subpiraticus, X2-Clubiona japonicola and X3-Tetragnatha japonica) for brown plant hopper (X4-Nilaparvata lugens) and rice spittle bug (X5-Cal-litettix versicolor) was investigated, as well as how interference between and within species occurred, by using a quadratic regression rotational composite design. Six predation models derived from the analysis of interactions among and within predators and preys were developed. The total predatory capacity of spiders on rice insect pests after coexistence for one day can be expressed as follows: Y3 = 32.795 + 2.25X1 + 1.083X2 + 0.5X3 + 10.167X4 + 3.167X5 - 1.67X12 - 2.42X22 - 3.295X32 - 0.045X42 + 0.455X52 - 3.125X1X2 + 0.375X1X3 -0.625X1X4 - 0.375X1X5 + 0.375X2X3 - 0.875X2X4 + 0.125X2X5 + 0.375X3X4 - 0.375X3X5 + 0.125X4X5. The principal efficiency analysis using this model indicated that increases in insect pest density significantly increased predation by predators; this was much greater than the effect of any single predator. X4 had a greater effect than X5; however, X4 and X5 demonstrated little interspecific interference and even promoted each other and increased predation rates as the densities of the two pests increased. Among the three predators, an increase in the density of X, had the greatest effect on the increase in predation, X3 had the second, X2 the third greatest effect. As predator density increased inter- and intra-species interference occurred, which were largely related to the size, activity, niche breadth, niche overlap and searching efficiency of the predators. X2 produced the greatest interference between different individuals and between any other predator species. X3 had the second greatest, which reduced predation levels at high predator densities. Because of these factors, the highest predation rate was obtained at a prey density of 120 per 4 rice-hills. The optimal proportion of the three predators in the multi-predator prey system was X1: X2: X3 = 5.6:1.3:4.1.

Species Investigation and Population Dynamic of Spiders in Tea Gardens in Northern Guangxi

A systematic investigation on spiders in a tea garden of Guilin Institute of Tea Sciences was conducted. The results showed that totally 687 specimens were collected, belonging to 34 species, 27genera, 14 families, 2 suborders, and a new record species Trochosa suiningensis in Guangxi was found. Spider is a ma- jor developing natural enemy group of insect pests in tea garden, with features of wide distribution, large quantity, long duration, strong predatory and stress resist- ance, which has strong predation on adults and nymphs of Empoasca vitis and young larvae of Ectropis oblique. The population of spiders in tea garden significantly increases after middle June, and reaches the peak in July and August every year.

Effects of Droplet Distribution on Insecticide Toxicity to Asian Corn Borers(Ostrinia furnaealis) and Spiders(Xysticus ephippiatus)

Distribution of horizontal boom produced droplets downwards into maize canopies at flowering period and its effects on the efficacies of emamectin benzoate, lambda-cyhalothrin and chlorantraniliprole against the second generation of Asian corn borer （ACB） larvae and their toxicity to spiders were studied. When insecticides were sprayed downwards into the maize canopies, randomly filtering out droplets by upper leaves led to great variations of droplet coverage and density within the canopies. Consequently, the efficacies of lambda-cyhalothrin and emamectin benzoate against ACB larvae were decreased because of randomly filtering out droplets by upper leaves. But field investigation showed that lambda-cyhalothrin was extremely toxic to hunting spiders, Xysticus ephippiatus, and not suitable to IPM programs in regulation of the second generation of ACB. Therefore, randomly filtering out droplets by upper leaves decreased lambda-cyhalothrin＇s efficacy against ACB larvae, but did little to decrease its toxicity to X. ephippiatus. Amamectin benzoate can reduce the populations of X. ephippiatus by 58.1-61.4%, but the populations can recover at the end of the experiment. Chlorantraniliprole was relatively safe to X. ephippiatus. It only reduced the populations of X. ephippiatus by 22.3-33.0%, and the populations can totally recover 9 d after application.

A Mechanical Model for the Adhesion of Spiders to Nominally Flat Surfaces

In dry attachment systems of spiders and geckos, van der Waals forces mediate attraction between substrate and animal tarsus. In particular, the scopula of Evarcha arcuata spiders allows for reversible attachment and easy detachment to a broad range of surfaces. Hence, reproducing the scopula's roughness compatibility while maintaining anti-bunching features and dirt particle repellence behavior is a central task for a biomimetic transfer to an engineered model. In the present work we model the scopula of E. arcuata from a mechano-elastic point of view analyzing the influence of its hierarchical structure on the attachment behavior. By considering biological data of the gecko and spider, and the simulation results, the adhesive capabilities of the two animals are compared and important confirmations and new directives in order to reproduce the overall structure are found. Moreover, a possible suggestion of how the spider detaches in an easy and fast manner is proposed and supported by the results.

Predator perception of detritus and eggsac decorations spun by orb-web spiders Cyclosa octotuberculata:Do they function to camouflage the spiders?

Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or eggsacs to their webs called web decorations. Web decorations resembling spider body colour pattern have been considered to camouflage the spider from predators. While this camouflage is obvious from a human＇s perspective, it has rarely been investigated from a predator＇s perspective. In this study, we tested the visibility of web decorations by calculating chromatic and achromatic contrasts of detritus and eggsae decorations built by Cyclosa octotubereulata, against four different backgrounds viewed by both bird （e.g., blue tits） and hymenopteran （e.g. wasps） predators. We showed that both juvenile and adult spiders on webs with detritus or egg-sac deco- rations were undetectable by both hymenopteran and bird predators over short and long distances. Our results thus suggest that decorating webs with detritus or eggsacs by C octotuberculata may camouflage the spiders from both hymenopteran and bird predators in their common habitats [Current Zoology 56 （3）： 379-387, 2010].

Comparative transcriptomics highlights convergent evolution of energy metabolic pathways in group-living spiders

Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among groupliving spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.

Predatory Efficacy of Cotton Inhabiting Spiders on Bemisiatabaci, Amrascadevastans Thripstabaci and Helicoverpa armigera in Laboratory Conditions

Distinction of predator＇s diet and prey choice preference is a hot topic of current investigations. Spider being generalist predator and cosmopoliter in nature acts as biological control agent in many agro-ecosystems. In the current study, predatory efficacy of five spiders （Pardosa birmanica, Cyclosa insulana, Thomisus projectus, Plexippus paykulli and Lycosa terrestris） inhabiting the cotton fieldevaluated in the laboratory conditions maintained at （27＋2）℃ temperature, 65%-5% relative humidity and 12 ： 12 h of light and dark photoperiod. Four key cotton pests＇ viz. Bemisiatabaci, Amrascaderastans Thripstabaci and Helicoverpa armigera were utilized in the choice and no-choice predatory studies. The findings of current investigation revealed that each predatory spider utilized at least one pest species. Predation rate was found higher in the no-choice predation because of unavailability of substitutes feeding source. The investigation also indicated each predatory spider killed more pests than consumed. The findings of this study support the predatory role of spiders in controlling the cotton major pests.

Investigation on Species of Spiders in Tea Plantations in Enshi Region of China

The spider resources in tea plantations in Enshi region have been investigated and 51 species of spiders belonging to 22 families have been identified in the paper. The dominant species are clarified and their directory and distribution status are also listed in the paper.

Diversity and Distribution of Spiders in Southwestern Nigeria

The study of diversity and distribution of spiders was carried out at Obafemi Awolowo University, Southwestern Nigeria, in wet and dry seasons between October 2012 and April 2014. Spiders were collected from five different sampling sites in the study area: cultivated land, open field, hill area, house dwelling and aquatic habitat. We found 1824 individuals belonging to 19 different spider families in the study area. 9 families of spiders were present in the hill habitat;12 families of spiders were present in the open field habitat;6 families of spiders were present in house habitat;9 families of spider were present in aquatic habitat. All the 19 families of spiders were present in cultivated habitat. Therefore, cultivated habitat hosted the largest number of spider families in the area of study while house dwellers hosted the least number of spider families. Spiders are evenly distributed among the five habitats in this study and the fifth habitat, teaching and research farm representing cultivated area has the highest distribution of spider species. All the species recorded in Southwestern Nigeria were found in this habitat. In conclusion, 19 different spider families are recorded in Obafemi Awolowo University, Nigeria, during this study. These have enriched the collection of spider in Natural History Museum, Obafemi Awolowo University, Southwestern Nigeria.

New cave-dwelling spiders of the family Dictynidae (Arachnida＂ Araneae) from Guangxi and Guizhou, China

Twenty-four new spider species of the family Dictynidae from caves of Guangxi and Guizhou in southern China are described, accompanied by line drawings and photomicroscopy images. Fifteen of them belong to Brommella Tullgren, 1948： B. baiseensis Li, sp. nov., B. casseabri Li, sp. nov., B. chongzuoensis Li, sp. nov., B. dolabrata Li, sp. nov., B. funaria Li, sp. nov., B. josephkohi Li, sp. nov., B. linyuchengi Li, sp. nov., B. renguodongi Li, sp. nov., B. resima Li, sp. nov., B. sejuncta Li, sp. nov., B. spirula Li, sp. nov., B. tongyanfengi Li, sp. nov., B. wangfengcheni Li, sp. nov,, B. xinganensis Li, sp. nov. and B. yizhouensis Li, sp. nov.; eight to Cicurina Menge, 1871： C. avicularia Li, sp. nov., C. damaoensis Li, sp. nov., C. dong Li, sp. nov., C. kailiensis Li, sp. nov., C. majiangensis Li, sp. nov., C. parallela Li, sp. nov., C. wusanani Li, sp. nov., and C. zhazuweii Li, sp. nov.; one to Lathys Simon, 1884： L. inaffecta Li, sp. nov. Types of all new species are deposited in the Institute of Zoology, Chinese Academy of Sciences in Beijing （IZCAS）.

Structural analysis of silk using solid-state NMR

Silkworms and spiders are capable of generating fibers that are both highly durable and elastic in a short span of time,using a silk solution stored within their bodies at room temperature and normal atmospheric pressure.The dragline silk fiber,which is essentially a spider's lifeline,surpasses the strength of a steel wire of equivalent thickness.Regrettably,humans have yet to replicate this process to produce fibers with similar high strength and elasticity in an eco-friendly manner.Therefore,it is of utmost importance to thoroughly comprehend the extraordinary structure and fibrillation mechanism of silk,and leverage this understanding in the manufacturing of high-strength,high-elasticity fibers.This review will delve into the recent progress in comprehending the structure of silks derived from silkworms and spiders,emphasizing the distinctive attributes of solidstate NMR.

Demonstrating mate choice copying in spiders requires further research

Mate choice copying-when individuals learn to prefer mates or mate types that have been chosen by others-can influence trait evo-lution and speciation(Varela et al.2018;Dion et al.2019).Most examples of mate choice copying are from fish,birds,and mammals including humans(Varela et al.2018).However,2 invertebrate examples-fruit flies and wolf spiders-have been used to argue that the phenomenon may be phylogenetically widespread,and perhaps the rule rather than the exception in nature(Varela et al.2018).Here,we revisit the evidence for mate choice copying in wolf spiders(Fowler-Fimn et al.2015)in light of new data(Gilman et al.2018).Then,we discuss why mate choice copying is a phenomenon that is likely to occur in wolf spiders,and why this deserves attention.

Sex chromosomes behavior and G-banding treatment of male meiosis in nuptial gift-giving spiders of the family Trechaleidae

Preliminary genetic studies in Trechaleidae spider family show high variation in sex chromosomes and high heterocigocity,suggesting high chromatin plasticity.The trechaleids Paratrechalea ornata,Trechalea bucculenta and Trechaleoides biocellata are present in Uruguay.Males offering nuptial gifts during courtship have been reported in P.ornata and T.bucculenta but not in T.biocellata.Nuptial gifts are an inherited trait probably highly affected by environmental factors,which play an important role in gene expression.We hypothesize that this trait could be associated with tissue-specific genes existing in G-bands.We investigate the male meiosis in these 3 species,their sex chromosome system and the effects of G-banding on their chromosomes,and elucidate genetic differences among them.Meiotic stages of the 3 species were submitted to Giemsa-staining and G-banding treatments.We observed a haploid number of n=11 in P.ornata and n=13 in both T.bucculenta and T.biocellata.Males from the 3 species presented an X_(1)X_(2)0 sex chromosome system,which is suggested as ancestral in Araneae.In P.ornata and T.bucculenta,both sex chromosomes were together and aligned in parallel until the segregation during anaphase I.In contrast to these species,sex chromosomes of T.biocellata usually remained distant from each other until diakinesis when they were observed associated in parallel disposition.Interstitial G-bands were similar in P.ornata and T.bucculenta,and they both differed from those in T.biocellata.The special behavior of sex chromosomes in T.biocellata as well as the different G-banding pattern of this species suggests the existence of novel modifications in this species.

The betaine-dependent remethylation pathway is a homocysteine metabolism pathway associated with the carnivorous feeding habits of spiders

Homocysteine(Hcy)is a sulfur-containing amino acid derived from the essential amino acid methionine(Met).Circulating levels of Hcy in animals can be increased by feeding on Met-enriched diets,which is generally considered harmful.Spiders are one of the largest groups of obligate carnivores and feed on animals high in protein and Met.We analyzed the Hcy metabolism pathways in 18 species of 3 taxa(Mammalia,Insecta,and Arachnida)and found that the betaine-dependent remethylation pathway(BRP)was present in all carnivorous arachnid species and mammals but absent in insects and red spider mites.We then studied the Hcy metabolism pathway in Pardosa pseudoannulata.In P.pseudoannulata,Hcy is metabolized through the transsulfuration pathway,BRP,and S-methylmethionine-dependent remethylation pathway.Because of a prior duplication event of the betaine homocysteine S-methyltransferase(BHMT)gene in the BRP,BHMTa and BHMTb are present in tandem in the genome of P.pseudoannulata.The high expression levels of BHMTa and its high abundance in detoxification tissues indicate that it plays an important role in the BRP;the ability of BHMTa and BHMTb to remethylate Hcy using betaine as substrate was similar.Compared with other Hcy metabolic enzyme genes,BHMT responded quickly to the application of Hcy or betaine.In sum,the BRP is important in Hcy metabolism in P.pseudoannulata and in other spider species.

完美音浪——法拉利12CILINDRI SPIDER

近日,法拉利12Cilindri Spider在迈阿密海滩上的一场独家活动上亮相。作为一款设计理念承袭自20世纪50与60年代法拉利Gran Turismo敞篷车的新款车型,该车将公路赛车无与伦比的性能、12缸发动机声浪以及长途驾驶舒适性结合在一起,并在设计上打破了法拉利双座berlinetta Spider跑车一贯的肌肉感,采用了一种更加未来主义、建立在纯粹形式基础上的设计语言。

Black-Widow Spiders May Improve Sex Life-Chileans

标题中的Black-Widow Spiders可以译成“黑寡妇蜘蛛”,这种蜘蛛是一种能残食其配偶的有毒雌蜘蛛。交配成功之后.即刻将雄蜘蛛吃掉,而自己则马上沦为widow,所以,这种蜘蛛的命名倒也合情合理。现在,智利的专家已经成功地利用黑寡妇蜘蛛的毒液制造了一种新的“伟哥”,这种新型“伟哥”不仅能医治阳痿,而且能使精子不育。

The response of spiders to less-focused non-crop habitats in the agricultural landscape along the lower reach of the Yellow River

Non-crop habitats have been suggested to impact local biodiversity significantly in agricultural landscapes. However, there have been few studies of the effects of less-focused non-crop habitats(orchard, wetland, pit and ditch) on variation of spider abundance. In this study, spiders in 30 woodlands were captured using pitfall traps in Fengqiu County, China, and the effects of local and landscape variations at different scales(50 m, 100 m, 200 m, 350 m and 500 m) on spider abundance were analysed. The most important variation that influenced spider abundance at the 500 m scale was the less-focused non-crop habitat(LNH) cover, and 10% was an appropriate proportion of LNH cover to sustain high level of spider diversity in the investigated landscape. Non-metric multidimensional scaling analyses revealed that there were significant differences in the spider composition among the high, medium and low LNH coverage. Based on indicator species analysis, different spider species were associated with landscapes with different levels of LNH cover. Lycosidae, which accounted for 48% of the total specimens, preferred woodland habitats neighbouring areas with high LNH cover. Compared with woodland habitats, LNH provided more diverse food sources and habitat to sustain more spider species in the study area. Furthermore, linear elements composed of vegetation, such as pits and ditches, may prevent agricultural intensification by enhancing landscape connectivity and providing habitats for different spiders. Our findings may provide a theoretical basis for biodiversity conservation in agro-ecosystems and top-down control of pests.

The ecological consequences of temperament in spiders

Ecological and evolutionary studies on spiders have been featured prominently throughout the contemporary behavio- ral syndromes movement. Here we review the behavioral syndromes literature devoted to spiders, and identify some ways in which behavioral syndromes can impact the function of spiders in ecological communities. We further highlight three general themes within the behavioral syndromes literature for which spiders have served as front running model systems： （1） how trait correlations beget performance trade-offs, （2） the influence that behavioral trait variants have on interspecific interactions and （3） mechanisms that aid in maintaining behavioral variation within-and among-populations. Research on behavioral syndromes con-tinues to grow at an impressive rate, and we feel the success of behavioral syndromes studies in spiders bodes well for their con-tinued prominence.