Native parasitoids of Dalbulus elimatus and Dalbulus maidis (Hemiptera: Cicadellidae) in winter crops of central Mexico

Few studies have explored the natural enemies of an insect pest on winter crops. This study describes native parasitoids of adult Mexican corn leafhopper, Dalbulus elimatus (Ball), and corn leafhopper, Dalbulus maidis (Delong & Wolcott) (Hemiptera: Cicadellidae), and evaluates their parasitism rate on winter maize, Zea mays (L.), barley, Hordeum vulgare L.; and sorghum, Sorghum bicolor (L.) Moench., during the winter season in central Mexico. The survey was conducted throughout an annual cycle, with sampling in the previous season’s crops when available. Leafhoppers showing evidence of parasitism were reared individually in the laboratory to obtain adult parasitoids for subsequent identification. Adult D. elimatus were parasitized on winter maize, barley, and sorghum by the fly Eudorylas subopacus (Loew) (Pipunculidae) and the wasp Gonatopus bartletti Olmi (Dryinidae), whereas adult D. maidis were parasitized by fly and wasp parasitoids on winter maize only. Both parasitoid species showed high parasitism rates from leafhopper adults during the winter season. The highest parasitism by E. subopacus for D. elimatus was 57.4% on maize, 39.6% on barley, and 48.8% on sorghum. The highest parasitism of E. subopacus for D. maidis was 20.4 % on maize. In contrast, the highest parasitism by G. bartletti for D. elimatus was 9.4% on maize, 2.7% on barley, and 25.8% on sorghum. The highest parasitism of G. bartletti for D. maidis was 7.1% on maize. These results indicate that winter crops are habitats of E. subopacus and G. bartletti during the winter season. This article is the first report of D. elimatus and D. maidis being parasitized by E. subopacus and of D. elimatus being parasitized by G. bartletti.