A new parasitoid from Kenya, Fopius ceratitivorus, complements the extant parasitoid guild attacking Mediterranean fruit fly in Hawaii
2010
Kroder, Stefan | Messing, Russell H.
The Mediterranean fruit fly (= medfly), Ceratitis capitata, is one of four tephritid species that are serious impediments to the development of a robust agricultural economy in Hawaii. Despite being the target of biological control programs dating back 100 years, medfly remains a direct pest and a quarantine pest, with high population reservoirs in coffee plantations, and limited parasitism at higher elevations. Fopius ceratitivorus, an egg-attacking parasitoid from Kenya, was introduced into quarantine and analyzed for its potential to complement the existing parasitoid guild attacking medfly in Hawaii. We determined host egg-stage preference, interactions of the new parasitoid with the extant egg-attacking parasitoid Fopius arisanus, and their relative performance under different thermal conditions. Both species prefer younger medfly eggs, but F. ceratitivorus is an inferior intrinsic competitor to F. arisanus on young eggs when both species have simultaneous access to hosts. Overall parasitism rates are higher in two species than in single-species exposures, mainly due to increased parasitization of older eggs. Fopius ceratitivorus has a broader temperature tolerance and a longer lifespan than F. arisanus over the temperature range from 22 to 30 °C. This suggests that establishment of F. ceratitivorus in Hawaii may improve overall suppression of medfly statewide. Broader temperature tolerance and longer lifespan may allow it to colonize cooler areas where F. arisanus is absent; and it is unlikely to interfere with the efficacy of F. arisanus at lower elevations, where the new species is an inferior competitor on young host eggs and does not successfully reproduce on the abundant alternate host Bactrocera dorsalis.
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