Spiders and harvestmen as gastropod predators

1. Reports are reviewed of gastropod feeding (malacophagy) by spiders and harvestmen. Although the standard textbooks on arachnids recognise the importance of gastropods as prey of harvestmen, none apparently refers to malacophagy by spiders. A review of several hundred papers on spider feeding habits revealed that species from several families kill and devour slugs and snails in the laboratory and/or field. 2. Malacophagy has been reported most frequently among mygalomorph spiders, and can make up a substantial proportion of the diets of some species, however gastropods make up an insignificant percentage of the prey of most araneomorph spiders. The spiders that eat gastropods are species with broad diets composed predominantly of arthropod prey. No species of spider appears to feed exclusively on gastropod prey. 3. Harvestmen from several families have broad diets that often include gastropods. Several species of the family Trogulidae and at least one species of the family Ischyropsalididae [Ischyropsalis hellwigi (Panzer)] are specialised gastropod predators. The trogulids are slender animals that attack the snail through the shell aperture (shell intruders). Ischyropsalis hellwigi, on the other hand, can crush snail shells with its powerful chelicerae (shell breakers). 4. The review highlights apparent convergent evolution by harvestmen and Carabidae of two mutually exclusive morphologies found among gastropod predators. It also suggests that there is an urgent need for systematic studies to be conducted to establish the extent and ecological importance of malacophagy in natural and anthropogenically altered habitats.     

山西历山国家级自然保护区蜘蛛名录

在经过多年野外调查、采集、室内显微鉴定的基础上,本课题组将采自山西历山国家级自然保护区已定名的蜘蛛种类名录整理于下,共包括18科45属71种,其中包括2个大陆新记录种,1个山西新纪录科,9个山西新纪录属,26个山西新记录种.     

Eocene Spiders from the Isle of Wight With Preserved Respiratory Structures

A new fossil spider, Vectaraneus yulei gen. et sp. nov., from the Eocene Bembridge Marls Insect Bed of the Isle of Wight, shows internal anatomy, including book lungs and tracheae, preserved by calcium carbonate replacement. The wide, medially positioned, tracheal spiracle and large tracheae which enter the prosoma are adaptations for an amphibious mode of life. The spider is placed in Cybaeidae Simon, 1898, Argyronetinae Menge, 1869, a subfamily which includes the Recent European Water Spider, Argyroneta aquatica (Clerck, 1757). The only previously described Bembridge Marls spider, Eoatypus woodwardii McCook, 1888, is redescribed; it is unrelated to Vectaraneus . The holotype of Argyroneta antiqua Von Heyden (1859) is redescribed; it is not an Argyroneta . Specimens referred to A. antiqua by Bertkau (1878) probably belong in Argyronetinae Menge, 1869, and this subfamily is emended herein.     

表面残留杀虫剂对蜘蛛的影响研究

以前的报道多集中于研究杀虫剂直接喷洒对蜘蛛的影响。本研究以三突花蛛和沟渠豹蛛为对象,测定了溴氰菊酯、毒死蜱和查虫清（植物源杀虫剂）共3种杀虫剂的表面残留对蜘蛛的驱避作用和急性毒性。结果表明：残留2h的毒死蜱和查虫清对三突花蛛无驱避作用,而残留2h的溴氰菊酯对三突花蛛有明显地驱避作用。3种杀虫剂的2h表面残留对沟渠豹蛛均有显著的驱避作用,其中溴氰菊酯的驱避作用最强。残留24h的3种杀虫剂对三突花蛛和沟渠豹蛛无明显的驱避作用。表面残留的毒死蜱和查虫清对蜘蛛的毒性小,溴氰菊酯的残留对三突花蛛和沟渠豹蛛毒性大。表面残留2h的溴氰菊酯对沟渠豹蛛的毒性显著高于残留24h的溴氰菊酯。     

Ballooning dispersal in arthropod taxa: conditions at take-off

We have solved a long-standing and seemingly paradoxical set of questions that relate to the conditions which govern spider ballooning. We show that observations of spider ballooning excursions are best explained by meteorological conditions which maximize dispersal. Dispersal is predicted to be most effective in terms of distance when the stability of the atmosphere is non-ideally convective and is less effective during purely convective or neutrally stable conditions. Ballooners are most likely to travel a few hundred metres, but dispersal distances of several hundred kilometres are possible.     

蜘蛛对茶园害虫控制作用的研究

1981年以来，湖南省兰岭茶园开展了大面积以保护茶园蜘蛛为主的茶园害虫综合防治技术研究。近10年来未打化学农药，4年未施化学肥料。试验结果表明，这些措施不但使以蜘蛛为主的茶虫天敌的种类增多、种群数量上升，而且使茶园内主要害虫的种群数量逐年下降；茶叶内不含任何农药残毒，产品达到国家AA级绿色食品要求；经济效益得到成倍增加。     

Visualization of single fluorophores in living cells

Methods applicable to visualizing single fluorophores in living cells are described, namely, laser epifluorescence, confocal, near-field, two-photon, and total internal reflection microscopy. It is demonstrated that total internal reflection microscopy is the most appropriate for visualizing single fluorophores near the substrate-medium interface. This method can be used for studying receptors, ion channels, and numerous cytoskeletal and signal molecules located on or near the basal cell membrane. It is demonstrated that stringent criteria are necessary when identifying single molecules, as these objects emit a limited number of photons before irreversible photobleaching and their fluorescence is obscured by autofluorescence or out-of-focus fluorescence. The methods used for studying the lateral mobility of single molecules floating on the cell membrane are also described.     

Fairy wrasses perceive and respond to their deep red fluorescent coloration

Fluorescence enables the display of wavelengths that are absent in the natural environment, offering the potential to generate conspicuous colour contrasts. The marine fairy wrasse Cirrhilabrus solorensis displays prominent fluorescence in the deep red range (650–700 nm). This is remarkable because marine fishes are generally assumed to have poor sensitivity in this part of the visual spectrum. Here, we investigated whether C. solorensis males can perceive the fluorescence featured in this species by testing whether the presence or absence of red fluorescence affects male–male interactions under exclusive blue illumination. Given that males respond aggressively towards mirror-image stimuli, we quantified agonistic behaviour against mirrors covered with filters that did or did not absorb long (i.e. red) wavelengths. Males showed significantly fewer agonistic responses when their fluorescent signal was masked, independent of brightness differences. Our results unequivocally show that C. solorensis can see its deep red fluorescent coloration and that this pattern affects male–male interactions. This is the first study to demonstrate that deep red fluorescent body coloration can be perceived and has behavioural significance in a reef fish.     

中国安蛛科(蜘蛛目)蜘蛛记述及一新纪录属Conculus

本文简要综述了我国安蛛科的研究现状,并描述了一种产自重庆洞穴的安蛛——Conculus lyugadinus Komatsu,1940,这是Conculus属在我国的首次报道.所有检视标本均保存在四川大学自然博物馆(SCUM).     

Spiders in wheat: First quantitative data for North America

Spiders were sampled quantitatively, by vacuum insect net (D-vac) followed by hand search, in Russian wheat aphid-resistant and -susceptible cultivars of winter wheat in Colorado. Spider densities were unaffected by cultivar, aphid density or wheat tiller density. Compared to other parts of the world, spider densities were one to two orders of magnitude lower, and the fauna more evenly dispersed over families rather than being dominated by the Linyphiidae. Given their very low densities, unmanipulated spider populations may be incapable of exerting significant biological control on cereal aphids in this system. Habitat manipulations such as those that have increased spider populations in wheat in Europe are under investigation.     

The 6-Methoxymethyl Derivative Of Pyrrolo-Dc For Selective Fluorometric Detection Of Guanosine-Containing Sequences

The β-cyanoethyl phosphosphoramidite derivatives of 6-methyl- and 6-methoxymethyl-3-(2-deoxy-β-D-ribofuranosyl)-3H-pyrrolo[2,3-d]pyrimidin-2-one have been synthesized. These monomers have been employed for oligodeoxynucleotide synthesis to evaluate their effect on duplex stability and ability to fluorometrically report on hybridization. The structurally conservative 6-methoxymethyl-substitution results in a pyrrolocytidine that is stabilizing toward hybrid formation (Δ Tm = +1.3 °C) whereas the known 6-methylpyrrolocytidine is destabilizing (Δ Tm = ?4.7 °C), in the sequence examined. The 6-methoxymethylpyrrolocytidine retains excellent mismatch discrimination and its fluorescence is selectively quenched when hybridized to a match oligodeoxynucleotide sequence. The quenching of fluorescence for an internal position is approximately three-fold, whereas a terminal position (5′-end or 3′-end) experienced approximately two-fold decrease in the fluorescence intensity.     

Advances in the Taxonomy of Spiders in Miocene Amber from the Dominican Republic (Arthropoda: Araneae)

Trachelas poinari sp. nov. (Corinnidae), Miagrammopes sp. indet. (Uloboridae) and the first indisputable fossil Lycosidae (gen. et sp. indet.) are newly identified and described in Miocene amber from the Dominican Republic. The following are junior synonyms: Nops segmentatus Wunderlich, 1988 of N. lobatus Wunderlich, 1988 (Caponiidae); Azilia muellenmeisteri Wunderlich, 1988 of A. hispaniolensis Wunderlich, 1988 (Tetragnathidae); and Lyssomanes galianoae Reiskind, 1989 of L. pristinus Wunderlich, 1986 (Salticidae). The specimens described as Nops sp. (Caponiidae), Selenops beynai Schawaller, 1984, S. sp. 1, and S. sp. 2 (Selenopidae) by Wunderlich (1988) are unrecognizable as distinct species. The following new combinations are presented: gen. indet. clypeatus (Wunderlich, 1988) (= Anelosimus clypeatus ) (Theridiidae); Meioneta bigibber (Wunderlich, 1988) (= Agyneta bigibber ), M. fastigata (Wunderlich, 1988) (= Agyneta fastigata ), M. separata (Wunderlich, 1988) (= Agyneta separata ) (Linyphiidae); Enacrosoma verrucosa (Wunderlich, 1988) (= Cyclosa verrucosa ) (Araneidae); Pseudosparianthis pfeiferi (Wunderlich, 1988) (= Tentabunda pfeiferi ) (Sparassidae). Theridion wunderlichi nom. nov. is proposed as a replacement name for T. ovale Wunderlich, 1988 (nom. preocc.). The previously unknown male of Styposis pholcoides Wunderlich, 1988 (Theridiidae) is described. Additional features of Argyrodes crassipatellaris Wunderlich, 1988 (Theridiidae) are described; this species is transferred from the trigonum to the cancellatus species group. Nine specimens belonging to six previously described species, and six juvenile Selenops sp. (including one exuvium) are newly identified. These are the first fossil records of Trachelas, Enacrosoma and Pseudosparianthis, giving them stratigraphic ranges of 15–20 my; the genera Anelosimus, Cyclosa and Agyneta are unknown in the fossil record.     

Macroecological patterns of spider species richness across Europe

We analysed the pattern of covariation of European spider species richness with various environmental variables at different scales. Four layers of perception ranging from single investigation sites to the whole European continent were selected. Species richness was determined using published data from all four scales. Correlation analyses and stepwise multiple linear regression were used to relate richness to topographic, climatic and biotic variables. Up to nine environmental variables were included in the analyses (area, latitude, elevation range, mean annual temperature, local variation in mean annual temperature, mean annual precipitation, mean July temperature, local variation in mean July temperature, plant species richness). At the local and at the continental scale, no significant correlations with surface area were found, whereas at the landscape and regional scale, surface area had a significant positive effect on species richness. Factors that were positively correlated with species richness at both broader scales were plant species richness, elevation range, and specific temperature variables (regional scale: local variation in mean annual, and mean July temperature; continental scale: mean July temperature). Latitude was significantly negatively correlated with the species richness at the continental scale. Multiple models for spider species richness data accounted for up to 77% of the total variance in spider species richness data. Furthermore, multiple models explained variation in plant species richness up to 79% through the variables mean July temperature and elevation range. We conclude that these first continental wide analyses grasp the overall pattern in spider species richness of Europe quite well, although some of the observed patterns are not directly causal. Climatic variables are expected to be among the most important direct factors, although other variables (e.g. elevation range, plant species richness) are important (surrogate) correlates of spider species richness.     

Efficiency of pyrimidine dimer formation in Escherichia coli across UV wavelengths

AIMS: Inactivation of Escherichia coli as a function of ultraviolet (UV) wavelength was investigated by using the endonuclease-sensitive site (ESS) assay to quantify pyrimidine dimer formation. METHODS AND RESULTS: Ultraviolet dose-response curves were determined based on both log reduction in colony-forming units (CFU) and endonuclease-sensitive sites per kb DNA (ESS/kb) for monochromatic 254-nm low-pressure (LP) UV, polychromatic medium-pressure (MP) UV, 228 and 289-nm UV irradiation. UV irradiation from LP and MP UV sources were approx. equal in both CFU reduction and pyrimidine dimer formation at all UV doses studied; 228-nm irradiation was less effective than LP or MP, and 289-nm irradiation was the least effective in both CFU reduction and pyrimidine dimer formation. These results are in qualitative agreement with the absorption spectrum of pyrimidine bases in DNA. Results indicated an approx. linear relationship between ESS/kb and log CFU reduction. CONCLUSIONS: Formation of pyrimidine dimers in genomic DNA is primarily responsible for UV inactivation of E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: This work contributed to fundamental understanding of UV disinfection and aids in UV reactor design.