Eficácia do padrão de coloração Preto-Laranja-Preto como estratégia aposemática em formigas-feiticeiras (Hymenoptera: Mutillidae)

Abstract

Some Mutillidae species exhibit a characteristic coloration pattern common in microhymenopterans, known as Black-Orange-Black (BOB). The BOB pattern observed in mutillids is correlated with body size, being more common in smaller species. It has been suggested that smaller individuals have a less resistant integument, making them more vulnerable to predatory attacks. Therefore, these species could significantly benefit from a signal that reduces their chances of being targeted by predators. The objective of this study was to evaluate the effectiveness of BOB coloration as an antipredator strategy via aposematism in female Mutillidae. Feeding trials were conducted with 31 spiders, including jumping spiders Plexippus paykulli (10), wolf spiders (10), and Nothroctenus sp. (11). Each spider was subjected to two trials with a BOB-patterned wasp, and the following data were recorded: (I) whether an attack occurred (yes/no), (II) time to the first attack on the prey (s), (III) number of attacks (n), and (IV) whether predation was successful (yes/no). After each trial, a typical prey item from the spiders’ diet was offered to verify if predation occurred. None of the spiders were able to consume the wasp offered, possibly due to their inability to pierce its exoskeleton. Wolf spiders avoided BOB-patterned wasps, suggesting a possible innate adaptation or prior learning. There was no significant difference in the time to the first attack between encounters with the wasp. However, the number of attacks between encounters was significantly different for P. paykulli. The results provide evidence of an effective aposematic defense against the tested invertebrate predators. Additional research, involving other predators and different contexts, will be essential to further understand the BOB coloration pattern in Mutillidae.