The role of larval aggression and mobility in the transition between solitary and gregarious development in parasitoid wasps

Citation
G. Boivin et J. Van Baaren, The role of larval aggression and mobility in the transition between solitary and gregarious development in parasitoid wasps, ECOL LETT, 3(6), 2000, pp. 469-474
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
ECOLOGY LETTERS
ISSN journal
1461-023X → ACNP
Volume
3
Issue
6
Year of publication
2000
Pages
469 - 474
Database
ISI
SICI code
1461-023X(200011)3:6<469:TROLAA>2.0.ZU;2-G
Abstract
Models explaining the appearance of gregariousness in insect parasitoids as sume the presence of a tolerance gene that enables nonsiblicidal behaviour in gregarious larvae. Under this assumption, nontolerant individuals should attack and kill tolerant individuals when sharing a host, making this beha viour susceptible to invasion by nontolerant individuals. We propose an alt ernative hypothesis where gregarious larvae retain their aggressiveness but are less mobile. We tested this hypothesis with two sympatric and congener ic species of Mymaridae, Anaphes victus and Anaphes listronoti, respectivel y, solitary and gregarious egg parasitoids of a Curculionidae, Listronotus oregonensis. Results obtained in competition experiments and from direct ob servation of movement in mymariform larvae of both species support the redu ced mobility hypothesis. By being immobile while retaining their fighting c apacity, A. listronoti mymariform larvae appear to optimize host utilizatio n through gregarious development, but can still defend themselves against s ympatric aggressive species.