Kin recognition in the social spiders Anelosimus sp. in Monteverde, Costa Rica

Anelosimus spiders are social and use pheromonal and vibrational cues to distinguish conspecifics from predators and prey. Juveniles live in their natal web with adults until maturity, at which time they disperse. Given that juveniles are more likely to disperse to locations near to their natal web and that Anelosimus has developed mechanisms for kin recognition, these spiders would be expected to exhibit aggressive behavior less frequently in the presence of intruding spiders from nearby webs than towards intruders from distant webs. This hypothesis was tested by introducing spiders to new webs from distant locations as well as from nearby locations. There was no significant relationship found between web distance and level of aggression (C2 = 5.47, df = 2, p = 0.06) nor between colony size and level of aggression (C2 = 2.43, df = 2, p = 0.30). A linear regression comparing colony size to level of aggression yielded no significant results for ignoring behavior (F = 0.94, df =1 and 18, p = 0.34), approaching behavior (F = 3.36, df = 1 and 18, p = 0.08), nor aggressive behavior (F = 0.29, df = 1, p = 0.59). According to this data there is little indication that spiders change their level of aggression due to colony size or distance between webs. This study provides data that can be used to explain the purpose and function of kin-recognition behaviors. Las arañas Anelosimus son individuos sociales que utilizan pistas como vibraciones y feromonas para distinguir conspecíficos entre los depredadores y las presas. Los juveniles viven en sus telas natales con los adultos hasta que maduran, tiempo al cual se dispersan. Con esto, los juveniles tienden mas a dispersarse a telas ubicadas cerca de la tela natal y estas especies tienen un mecanismo de reconocimiento de parentela, se espera en estas arañas un comportamiento agresivo menos frecuente con la presencia de arañas cercanas a la tela que con las arañas intrusas de telas lejanas.https://digitalcommons.usf.edu/tropical_ecology/1251/thumbnail.jp