Author
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WALSH, G. CABRERA - USDA/ARS/SABCL |
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Submitted to: Biological Control
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/8/2003 Publication Date: 10/20/2004 Citation: Biological Control 29 (2004) 427-434 Interpretive Summary: The genus Diabrotica (corn rootworms and cucumber beetles)includes a great number of pest species, including some of the most important crops pests of the Americas. However, only five parasitoid species have been recorded for it. The parasitoidal fly (Tachinidae) Celatoria bosqi Blanchard was the first parasitoid described in Diabrotica spp. in South America, and large natural infestations have been observed. The objectives of this work are to report field observations, and results of experiments on the reproductive biology and ecology of C. bosqi, including their host range, distribution, and environmental constraints, in order to evaluate its potential as a biocontrol agent against North American corn rootworms. C. bosqi has been collected almost throughout the South American distribution area of its main host, in an area that includes temperate and tropical lowlands, and semiarid to humid highlands. Three Diabroticina species were found to host the parasitoid, D. speciosa (Germar), D.viridula (F.), and Hystiopsis sp., suggesting it is specific to the subtribe, and is liable to adapt to the North American pest species. Laboratory experiments with field beetles and puparia reared in the laboratory, indicate C. bosqi overwinters obligatorily in overwintering adult host beetles, remaining quiescent in its live host below developmental temperatures. Based on the known climatic range of C. bosqi, and its requirement of adult overwintering hosts, I suggest a potential distribution in North America. Technical Abstract: The genus Diabrotica (Coleoptera: Chrysomelidae) includes a great number of pest species, including some of the most important crops pests of the Americas. However, only five parasitoid species have been recorded for it. The parasitoid Celatoria bosqi Blanchard was the first parasitoid described in Diabrotica spp. in South America, and large natural infestations have been observed. C. bosqi has been collected almost throughout the South American distribution area of its main host, Diabrotica speciosa (Germar), in an area that includes temperate and tropical lowlands, and semiarid to humid highlands. Three Diabrotica species were found to host the parasitoid, D. speciosa (Germar), Hystiopsis sp., and D. viridula (F.), with a total parasitism of 2.60, 5.55, and <0.02%, respectively. Laboratory experiments with field beetles and puparia reared in the laboratory, indicate C. bosqi overwinters obligatorily in overwintering adult host beetles, remaining quiescent in its live host below developmental temperatures. Based on the known climatic range of C. bosqi, and its requirement of adult overwintering hosts, a potential distribution in North America is projected. |
