中国妩蛛科一种社会性蜘蛛初报及新种记述(蜘蛛目,妩蛛科)

报道并描述了一种隶属于蛛形纲蜘蛛目妩蛛科的社会性蜘蛛:翼状喜妩蛛Philoponella alata sp.nov.。模式标本保存于中国科学院动物研究所。本种是中国第1次报道的社会性蜘蛛。翼状喜妩蛛,新种Philoponella alata sp.nov.(图1~9)正模♂,副模2♀♀,32♂♂,云南省西双版纳州勐腊县勐仑镇中国科学院西双版纳热带植物园,2006年12月24日,李枢强采集。新种与产自南美洲的条纹喜妩蛛P.vittata(Keyserling,1881)相近,两者的主要区别:前者触肢引导器基片呈一完整的翼状,后者窄长;前者外雌器生殖孔为一近似等边三角形,后者圆形;前者受精管有3个弯结,然后变端直,后者则明显不同。     

Population studies of two colonial orb-weaving spiders

Colonial spiders have individual capture webs (territories) within a communally shared web structure. I describe here the life histories and colony population dynamics of two communal species, Ctrtophora moluccensis (Doleschall) (Araneidae) in Papua New Guinea and Philoponella republicana (Simon) (Uloboridae) in the Panama Canal Zone. In both species, dispersal and foundation of new colonies are primarily by groups of immatures. Population growth of new-colonies was rapid during the first generation, but then colony population size decreased markedly. Colonies of P. republicana rarely lasted more than one generation, whereas those of C. moluccensis attained an equilibrium population size and often persisted for many generations at the same site. Reproduction occurred during the wet season in P. republicana colonies and year-round in colonies of C. moluccensis. Reproduction was synchronized in widely separated colonies of P. republicana. Factors controlling population growth and survival of colonies are discussed. Cyrtophora moluccensis colonies were probably regulated by density dependant factors, especially predation and parasitism, and perhaps a shortage of flying insects due to colony visibility. Philoponella republicana colonies were most likely limited by climatic conditions and instability of the habitat (i.e. density independent factors). Colonial social organization influences both dispersal and colony population growth. Coloniality is, however, compatible with various life history strategies.     

Foraging behavior of the communal spider,Philoponella republicana (Araneae: Uloboridae)

The communal orb-weaving spider, Philoponella republicana,was observed in the subtropical moist forest of Southeast Peru. These spiders live in colonies of conspecifics whose individual orbs are connected by silk. The wrapping of a prey prior to feeding is a large component of the prey capture process because P. republicanahas no venom with which to kill an insect. Wrapping time was the only aspect of prey capture that was strongly correlated with the size of the insect captured. Occasionally we observed several individuals working together to wrap a prey item. These joint efforts were more frequent on prey larger than the capturing spider. Although group captures accounted for only 5.5% of captures, they represented 14.7% of the biomass obtained. A comparison of the relationship between wrapping time and prey size for solitary and group efforts suggested that, by working together, the spiders reduced their total handling time. In most cases only one spider fed on the captured prey.