中国蚁蛛属一新种记述(蜘蛛目:跳蛛科)

记述了我国蚁蛛属1新种：短螯蚁蛛Myrmarachne brevis sp.nov.,标本采自云南景洪和广西北海,保存在白求恩医科大学生物教研室和湖南中医学院生物教研室。正模测量如下（单位：mm),体长6．82,头胸部长3．05,腹部长3．50,眼区长1．26,第1眼列宽1．45,第3眼列宽1．50,头胸部背面棕红色,眼周围黑色,眼区中央有1对短棒状黑褐斑,螯肢较短小,触肢器圆饼状,贮精囊如“C”型弯曲的肠管状。     

Innate aversion to ants (Hymenoptera: Formicidae) and ant mimics: experimental findings from mantises (Mantodea)

Field data suggest that ants may be important predators of mantises which, in turn, may be important predators of jumping spiders (Salticidae). Using a tropical fauna from the Philippines as a case study, the reactions of mantises to ants, myrmecomorphic salticids (i.e. jumping spiders that resemble ants) and ordinary salticids (i.e. jumping spiders that do not resemble ants) were investigated in the laboratory. Three mantis species ( Loxomantis sp., Orthodera sp., and Statilia sp.) were tested with ten ant species, five species of Myrmarachne (i.e. myrmecomorphic salticids), and 23 ordinary salticid species. Two categories of the myrmecomorphic salticids were recognized: (1) 'typical Myrmarachne ' (four species with a strong resemblance to ants) and (2) Myrmarachne bakeri (a species with less strong resemblance to ants). Ants readily killed mantises in the laboratory, confirming that, for the mantises studied, ants are dangerous. In alternate-day testing, the mantises routinely preyed on the ordinary salticids, but avoided ants. The mantises reacted to myrmecomorphic salticids similarly to how they reacted to ants (i.e. myrmecomorphic salticids appear to be, for mantises, Batesian mimics of ants). Although myrmecomorphic salticids were rarely eaten, M . bakeri was eaten more often than typical Myrmarachne . Because the mantises had no prior experience with ants, ant mimics or ordinary salticids, our findings suggest that mantises have an innate aversion to attacking ants and that this aversion is generalized to myrmecomorphic salticids even in the absence of prior experience with ants. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 23–32.     

中国云南蚁蛛属一新种记述(蜘蛛目,跳蛛科)

记述了产于我国云南的蚁蛛1新种:环蚁蛛 Myrmarachne circulus sp.nov.,标本采自云南勐腊,保存在湖南师范大学生命科学院,量度单位为mm.新种与黄蚁蛛Myrmarachne plataleoides(Cambridge,1869)相似,但有以下区别:1)雄蛛螯肢外侧近平直,后者呈"P"形;2)生殖球肥大,后者较细小;3)贮精管粗大,半环形,后者较细小,呈"S"形;4)兜位于外雌器中下部,后者位于下部.     

河内蚁蛛雌性记述(蜘蛛目,跳蛛科)

首次发现并报道了采自云南的跳蛛科蚁蛛属河内蚁蛛Myrmarachne hanoii,Zabka,1985的雌性个体。为我国新纪录种。文中详细描述了本种雌性个体的特征及与其近似种的比较,同时附有特征图。研究标本保存于湖南中医药大学。     

Dynamics of the evolution of Batesian mimicry: molecular phylogenetic analysis of ant-mimicking Myrmarachne (Araneae: Salticidae) species and their ant models

Batesian mimicry is seen as an example of evolution by natural selection, with predation as the main driving force. The mimic is under selective pressure to resemble its model, whereas it is disadvantageous for the model to be associated with the palatable mimic. In consequence one might expect there to be an evolutionary arms race, similar to the one involving host-parasite coevolution. In this study, the evolutionary dynamics of a Batesian mimicry system of model ants and ant-mimicking salticids is investigated by comparing the phylogenies of the two groups. Although Batesian mimics are expected to coevolve with their models, we found the phylogenetic patterns of the models and the mimics to be indicative of adaptive radiation by the mimic rather than co-speciation between the mimic and the model. This shows that there is strong selection pressure on Myrmarachne, leading to a high degree of polymorphism. There is also evidence of sympatric speciation in Myrmarachne, the reproductive isolation possibly driven by female mate choice in polymorphic species.     

Prey classification by an araneophagic ant-like jumping spider (Araneae: Salticidae)

What to attack is one of the most basic decisions predators must make, and these decisions are reliant upon the predator's sensory and cognitive capacity. Active choice of spiders as preferred prey, or araneophagy, has evolved in several distantly related spider families, including jumping spiders (Salticidae), but has never been demonstrated in ant-like jumping spiders. We used prey-choice tests with motionless lures to investigate prey-choice behaviour in Myrmarachne melanotarsa , an East African ant-like salticid that normally lives in aggregations and often associates with other spider species. We show that M . melanotarsa chooses spiders as prey in preference to insects and, furthermore, discriminates between different types of spiders. Myrmarachne melanotarsa 's preferred prey were juvenile hersiliids and its second most preferred were other salticids. To date, all documented examples of araneophagic salticids have been from the basal subfamily Spartaeinae. Myrmarachne melanotarsa is the first non-spartaeine and also the first ant-like salticid for which araneophagy has been demonstrated.     

The natural history of Myrmarachne melanotarsa,a social ant‐mimicking jumping spider

Abstract

Myrmarachne melanotarsa, an ant‐like jumping spider (Salticidae) from East Africa, is an accurate mimic of Crematogaster sp. and associates unusually closely with its models. M. melanotarsa is remarkable in that it forms dense aggregations and builds large nest complexes (numerous individually‐occupied nests connected to each other by silk). Other salticids (Pseudicius spp., Menemerus spp.) live with M. melanotarsa in the same nest complex. These aggregations, which can exceed 50 conspecific individuals per colony, are considerably larger than those few previously described, and seem to have primarily a protective function. We provide baseline information on the natural history of M. melanotarsa, paying particular attention to predatory behaviour and association with Crematogaster sp., and fit this within current theory on the function of sociality in spiders. Other unusual behaviour of M. melanotarsa includes “mouthing”, in which the spider opens and closes its chelicerae while pressing its mouthparts against nest silk. We investigated the role of prior presence of Crematogaster sp. on nest silk in eliciting this previously unreported behaviour.