Larval aggregation in a Neotropical butterfly: risky behaviors, per capita risk, and larval responses in Ascia monuste orseis

Autor(es)

Santana, Alessandra F. K. ^{[1, 2]} ; Rodrigues, Daniela ^{[3, 4]} ; Zucoloto, Fernando S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Biol, Fac Filosofia Ciencias & Letras Ribeirao Preto, Ave Bandeirantes 3900, BR-14040900 Ribeirao Preto, SP - Brazil

^[2] Inst Fed Educ Ciencia & Tecnol Sao Paulo, Dept Recursos Nat, Ave C-1, 250, BR-14781502 Barretos, SP - Brazil

^[3] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, CP 6109, BR-13083970 Campinas, SP - Brazil

^[4] Univ Fed Rio de Janeiro, Dept Ecol, Inst Biol, Ctr Ciencias Saude, CP 68020, BR-21941902 Rio De Janeiro, RJ - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY; v. 71, n. 12 DEC 2017.
• Citações Web of Science: 2

Resumo

Gregariousness in insects has been shown to improve performance, feeding, and defense against predation. Nevertheless, an increased risk of antagonistic interactions such as competition and predation occurs in group living. We examined the effects of both group size and larval age of aggregations of the butterfly Ascia monuste orseis (Godart, 1819) on larval permanency and attack by natural enemies. Group behavior was also investigated with respect to predation risk, as well as larval responses after enemy attack. One larva and groups of 10 and 50 larvae were assigned on host plants and monitored daily to evaluate larval permanency. At each instar, a subset of groups was observed for a 4-h period to identify natural enemies and to record both group behaviors performed at the moment of attack and responses to the attacks. Permanency on the host was higher in aggregations than in solitary larvae. Larger aggregations conferred greater protection to A. monuste orseis larvae against natural enemies than did smaller aggregations, through lower per capita predation. Parasitoidism was more intense in small-sized larvae, whereas late instars were more susceptible to predators. Similarly to solitary species, larvae were most susceptible to attacks when performing searching and feeding compared to resting and moving. Moving away and headrearing were observed for all instars and groups after enemy attacks and rarely protected larvae against natural enemies. Our results show that behaviors that involve head movements posed more attack risks than those that involve moving the whole body or absence of movements, and that larval aggregation in A. monuste orseis rarely exhibits defensive behaviors against natural enemies. Larval defense is provided through dilution effect. (AU)

• Processo FAPESP: 07/07802-4 - Avanços no estudo da polifagia em lepidópteros neotropicais
• Beneficiário: Daniela Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 10/50816-9 - Influência da agregação larval em uma população selvagem de Ascia monuste orseis (Lepidoptera, Pieridae) e do canibalismo de ovos no tamanho dos agregados larvais
• Beneficiário: Fernando Sergio Zucoloto
• Modalidade de apoio: Auxílio à Pesquisa - Regular