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Avoidance of the host immune response by a generalist parasitoid, Compsilura concinnata Meigen
Author(s) -
CARON VALERIE,
JANMAAT ALIDA F.,
ERICSSON JERRY D.,
MYERS JUDITH H.
Publication year - 2008
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/j.1365-2311.2008.01002.x
Subject(s) - parasitoid , biology , host (biology) , hemolymph , tachinidae , zoology , parasitism , immune system , ecology , immunology
1. Ecological interactions between parasitoids and their hosts are extremely strong as parasitoid offspring rely entirely on an individual host to complete development. The ability of a parasitoid to use a host is influenced directly by the degree to which the parasitoid can overcome host defences and grow within the host. 2. Hymenopteran parasitoids have evolved different host‐specific strategies to defeat the host immune system, such as the use of venom, endosymbiont virus, or mimicking the host tissue. Dipteran parasitoids from the Tachinidae family do not use these subterfuges and rely mainly on avoiding the host immune system by hiding in specific tissues. 3. Little is known of the effect of this strategy on the host immune system, the absorption of nutrients by the parasitoid larvae, or the implications for parasitoid host range. 4. In this study, the impact of a polyphagous tachinid parasitoid Compsilura concinnata Meigen on a pest lepidopteran Trichoplusia ni Hübner are assessed. Phenoloxidase levels and haemolymph proteins were measured in parasitised T. ni as a function of host immune response. 5. Haemolymph phenoloxidase in the host did not vary with parasitisation but was triggered when a piece of monofilament was implanted in the haemocoel. Haemolymph proteins were depleted in heavily parasitised T. ni . 6. These results indicate that C. concinnata has a strategy that avoids the host immune system, and accesses the necessary nutrients for larval growth. This strategy could explain the success of this tachinid and its wide host range.