Profesor University of Guadalajara Zapopan, Jalisco, Mexico
Maize (Zea mays subsp. mays), an important cereal crop worldwide, was domesticated directy from the annual teosinte (Zea mays subsp. parviglumis), and teosintes originated from gamagrass (Tripsacum)plants. Field experiments were conducted in the Mesoamerican region of origin of maize, using baited host plants with eggs of the herbivore leafhopper Dalbulus, an insect that coevolved with Zea and Tripsacum. A community of parasitic wasps was found attacking eggs of Dalbulus quinquenotatus and D. maidis in Tripsacum wild habitat. The largest abundance of parasitoids adult emergence and rate of parasitism was found in D. quinquenotatus eggs laid on T. dactyloides. The rate of parasitism was similar for D. maidis eggs laid on teosinte, landrace, and hybrid maize within the Tripsacum habitat. In addition, a community of parasitic wasps was found attacking eggs of D. maidis within the annual teosinte wild habitat and maize agroecosystem. No differences were found in the abundance of emerged adult parasitoids and rate of parasitism from baited landrace maize and baited annual teosinte within the annual teosinte habitat and within the maize agroecosystem. In the maize agroecosystem, a strong positive density-dependent association was seen between the number of D. maidiseggs and the community of parasitoids. Results suggest that performance of egg parasitoids has not decreased through maize breeding, due to parasitic wasps did not show differences in the abundance and attack rate of D. maidis eggs laid on hybrid maize, landrace maize, and annualteosinte under field conditions.
