寡居种悦目金蛛若蛛群居机制初步研究

对寡居种悦目金蛛Argiope amoena若蛛群居生活对其结网的影响、温度和种群大小对若蛛存活率的影响、若蛛对限制性空间的利用及其扩散方式进行了观察和研究.结果表明,若蛛从卵袋出蛰后不经历群居扩散即具备结网能力,可结完整网,也具备在扩散前不进食水存活的能力;在变温条件下若蛛存活率要远远高于室温条件下的存活率,而在室温条件下若蛛开始死亡和半数死亡的时间比其聚居期长得多;若蛛主要通过群体空中扩散的方式进行扩散,可以减小能耗与敌害的威胁;不同种群大小的若蛛在限制性空间的分布均从第5d左右开始发生较大变化的,这与在空间不受限的条件下若蛛在第5d开始扩散的结果是一致的.据此我们推断:个体扩散代价最小化(包括御敌和能耗)和维持种群较高的生存率可能是寡居种悦目金蛛若蛛群居生活的主要原因.

The Primary Studies on the Social Mechanism of Solitary Argiope amoena Spiderling

In this study,the web conditions of spiderlings with and without social experience,the spiderling livability at different temperature and population size,the spiderling dispersal ways of solitary spider Argiope amoena were observed and investigated.It was found that the spiderlings hatched out from egg sac owned webbing and living ability without feeding and were able to weave a complete web without social and dispersal experiences.The livability of spiderlings at the high-low alternant temperatures increased in contrast to that of at room temperature.The times duration that spiderling began to die till half die off were much longer than their gregarious phase.The spiderlings dispersed mainly through the ballooning,an aerial dispersal way,which might decrease the energy consumption and threats from the natural enemy as well as atrocious entironment.The distributions of spiderlings with different population size in the restricted space greatly varied on the about 5th day.This result was consistent with that of the uncontrolled space,which indicates that the main reasons for spiderling sociality of the solitary spider Argiope amoena are probably to minimize of dispersal costs and to maintain the higher livability or viability.