INDICASAT AIP Building 219, City of Knowledge, Clayton, Panama, POBox 0843-01103, Ciudad del Saber, Panama.
Programa Centroamericano de Maestría en Entomología, Vicerrectoría de Investigación y Postgrado, Universidad de Panamá, Avenida Simón Bolívar, 0824, Panama.
Sci Rep. 2018 Feb 26;8(1):3599. doi: 10.1038/s41598-018-21971-0.
Spiders show a repertoire of strategies to increase their foraging success. In particular, some orb-weaver spiders use attractive body colorations to lure prey. Interestingly, coloration varies with age in many species, which may result in ontogenetic variation of foraging success. By using field observations, laboratory experiments and spectrophotometric analysis, we investigated whether pale juveniles and bright adults of the orb-weaver Alpaida tuonabo use different foraging strategies due to ontogenetic variation in coloration. Field observations revealed that foraging success of juveniles and adults was influenced by web properties. However, foraging success increased with body size only in adults, supporting the idea that larger individuals produce a stronger visual signal for prey. The attractiveness of the adult coloration for prey was confirmed in the laboratory with frame-web-choice experiments, in which webs bearing a spider intercepted more bees than empty webs. Our spectrophotometric analysis suggests that the yellow coloration may produce the deceiving signal for prey. Moreover, we identified potential alternative foraging strategies: cryptic juveniles at higher heights and 'attractive' adults at lower heights. This study reveals how ontogenetic colour variation may favour the use of alternative foraging strategies in orb-weaver spiders and reduces intraspecific competition.
蜘蛛表现出一系列策略来增加觅食成功的机会。特别是一些圆蛛会使用有吸引力的身体颜色来诱捕猎物。有趣的是，许多物种的颜色会随着年龄的增长而变化，这可能导致觅食成功的个体发育变化。通过使用野外观察、实验室实验和分光光度分析，我们研究了 Alpaida tuonabo 圆蛛的幼体和成虫是否由于颜色的个体发育变化而使用不同的觅食策略。野外观察表明，幼体和成虫的觅食成功率受到蛛网特性的影响。然而，只有成体的觅食成功率随体型增大而增加，这支持了较大个体为猎物产生更强视觉信号的观点。在实验室的框架网选择实验中，带有蜘蛛的网比空网吸引了更多的蜜蜂，从而证实了成虫颜色对猎物的吸引力。我们的分光光度分析表明，黄色可能会给猎物发出欺骗性信号。此外，我们还确定了潜在的替代觅食策略：处于较高位置的隐蔽幼体和处于较低位置的“有吸引力”的成体。这项研究揭示了个体发育颜色变化如何有利于圆蛛使用替代觅食策略，并减少种内竞争。
