A study of the parasitoids of Dalbulus maidis(DeLong and Wolcott) was conducted in Mexico, the putative center of origin of this leafhopper. The adults of D. maidis, a vector of maize pathogens, with external evidence of parasitism were searched at the end of two (2000-2001) dry seasons throughout the pacific, atlantic, and central regions of Mexico on 58 irrigated maize fields. Moreover, I compared the parasitism of D. maidis in two (irrigated maize and grasses on ex-maize fields)agronomic systems practiced in Mexico during the dry season. Results show that D. maidis is parasitized at 42% at the sites where leafhopper adults were collected at the end of the two dry seasons. The dipteran Metadorylas spinosus(Hardy) (Pipunculidae) was found in two sites, the strepsipteran Halictophagus naulti Kathirithamby and Moya-Raygoza (Halictophagidae) in nine sites, and the hymenopteran Gonatopus bartletti Olmi (Dryinidae)in 13 sites. M. spinosus is a previously unreported parasitoid of D. maidis. The parasitoids were distributed between sea level to 1,203 m altitude, which overlapped with the altitude distribution of D. maidis and the pathogen, corn stunt spiroplasma. Parasitized adults of D. maidis were found on irrigated maize fields during most of the dry season, while unparasitized adults of D. maidis were found during the dry season on grasses grown on ex-maize fields. The results suggest that the parasitoids of D. maidis overwinter in D. maidis which in turn overwinter on irrigated maize fields.
Species 1: Homoptera Cicadellidae Dalbulus maidis (corn leafhopper)
Species 2: Hymenoptera Dryinidae Gonatopus bartletti
Species 3: Diptera Pipunculidae Metadorylas spinosus
Keywords: biological control, maize
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