Performance and host preference of Ascia monuste (Lepidoptera, Pieridae) wild immatures in food change and deprivation of different hosts / Performance e preferência de imaturos selvagens de Ascia monuste (Godart, 1819) (Lepidoptera, Pieridae) na mudança e na privação de hospedeiros alimentares diferentes

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Ascia monuste (Lepidoptera, Pieridae) caterpillars are Brassicaceae specialists, being one of the most important comsumers of this plant family in the Neotropical region. In the field, a high proportion of immatures migrates to other hosts in order to develop properly, probably facing some variation in terms of nutritional value and location of their hosts. The main objective of this study was to investigate how the feeding of caterpillars of same ontogenetic phase on different hosts [kale (Brassica oleracea L. var. acephala) and rucola (Eruca sativa L.), and kale and cabbage (Brassica olerace L. var. capitata)], affects the corresponding performance of A. monuste. The hosts above mentioned differ in their nitrogen content: kale and rucola have similar nitrogen quantity, and kale has higher quantity than cabbage. In addition, it was evaluated whether the previous host would influence food choice in subsequent larval instar, in the field and in laboratory, as well as the effects of 24 hours of food deprivation on immature performance before switching the host. Beside few differences caused by host switching, possibly by the differences in nutrient levels, all the feeding tests originated similar performances and viable adults. When the preference was determined by the first caterpillar ingestion, previous experience did not influence host choice: caterpillars chose rucola instead of kale, and kale instead of cabbage, independently of previous host. But, when preference was determined by the total amount of ingested food, previous experience acted as a fagoestimulant in kale and rucola as hosts. It was not possible to detect what determine larval preference in the field. All plants tested were attractive for the caterpillars and the migration may occur for hosts that are close and easier to find. The 24 h food deprivation did not increase the effects of host change, but did present some differences. Rucola and cabbage could be less adequate hosts on final instars, because pupae whose larvae ingested these crucifers presented, in general, less pupal mass and also less oocytes, even when food deprivation does not occured.

ASSUNTO(S)

food deprivation. preference ascia monuste brassicaceae comportamento alimentar ascia monuste lepidoptera brassicaceae host change preferência alimentar

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