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Patch exploitation strategies of parasitoids under indirect intra‐ and inter‐specific competition
Author(s) -
ROBERT FÉLIXANTOINE,
BRODEUR JACQUES,
BOIVIN GUY
Publication year - 2016
Publication title -
ecological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0307-6946
DOI - 10.1111/een.12328
Subject(s) - biology , competition (biology) , parasitoid , hymenoptera , ovipositor , trichogrammatidae , foraging , host (biology) , intraspecific competition , generalist and specialist species , interspecific competition , ecology , zoology , habitat
1. Insect parasitoids are expected to evolve behavioural strategies to exploit resources in competitive environments optimally. Indirect competition between parasitoids is particularly common because exploited host patches remain available in the environment for other foraging individuals. 2. The effects of indirect competition on the behaviour of two closely related generalist egg parasitoids were investigated: T richogramma pintoi V oegelé and T richogramma minutum R iley ( Hymenoptera: Trichogrammatidae ). Patch residence time, a patch‐leaving mechanism, and progeny sex allocation of females foraging were analysed: (i) alone, (ii) in patches partially parasitised by conspecifics, and (iii) in patches partially parasitised by heterospecifics. 3. Each species responded differently to indirect competition. T richogramma pintoi females shortened their patch residence times, but they did not adjust their progeny sex ratios. In contrast, T. minutum females did not modify their patch residence times, but they did increase their progeny sex ratios in response to competition. Both T richogramma species used host rejection, either by antenna rejection or by ovipositor rejection, as a patch‐leaving mechanism. 4. In agreement with a companion study of direct competition using the same model species, the present results indicate that even amongst closely related species, responses to competition can vary considerably.