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THE ALLOCATION OF SEARCHING TIME BY TRICHOGRAMMA PRETIOSUM IN HOST‐CONTAINING PATCHES
Author(s) -
MORRISON GEROLD,
LEWIS W. JOE
Publication year - 1981
Publication title -
entomologia experimentalis et applicata
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 83
eISSN - 1570-7458
pISSN - 0013-8703
DOI - 10.1111/j.1570-7458.1981.tb03581.x
Subject(s) - trichogrammatidae , biology , parasitoid , kairomone , trichogramma , hymenoptera , host (biology) , lepidoptera genitalia , noctuidae , braconidae , ecology
Trichogramma pretiosum*** Riley (Hymenoptera: Trichogrammatidae), a generalist parasitoid of lepidopteran eggs, intensifies search in patches contaminated by a kairomone associated with Heliothis zea (Boddie) (Lepidoptera: Noctuidae) oviposition sites. In the laboratory the parasitoid will search any kairomone‐treated patch, abandoning standardized (10 cm diam) patches if no hosts are located within 60–180 sec. Total time and searching time on patches in which hosts are discovered are more highly correlated with the number of hosts attacked (N ha ) per patch than with actual host density. The parasitoid's perception of host density per patch is often “incorrect” in this sense. Handling time (T h ) and time “wasted” in re‐handling hosts parasitized earlier in the patch visit consume a large proportion of total patch time. Several hypotheses which have been suggested to explain patch time allocation by other parasitoids and predators appear inapplicable to T. pretiosum . The ratio of re‐encounters with parasitized hosts to the number of hosts attacked appears to affect the allocation of patch time by this species. The results of previous field experiments are compared to laboratory observations of searching behavior.