Evaluation of six maize hybrids for their susceptibility to feeding bythree Diatraea spp. (Lepidoptera : Crambidae) by using laboratorybioassays

摘要

Maize, Zea mays L., germplasm lines with resistance to leaf feeding by the southwestern corn borer, Diatraea grandiosella Dyar, have been developed and released. We determined if hybrids developed from these germplasm lines are also resistant to two other Diatraea spp. that attack maize in the United States [southern corn stalk borer, D. crambidoides (Grote), and the sugarcane borer, D. saccharalis (F.)]. Evaluation of three southwestern corn borer resistant and three susceptible maize hybrids for level of susceptibility to the southern corn stalk borer and sugarcane borer was done by feeding the larvae reconstituted ground, lyophilized whorl leaf tissue diets in the laboratory. Larvae of the southern corn stalk borer, sugarcane borer, and southwestern corn borer grown on the resistant leaf tissue diets were significantly smaller than those reared on the susceptible leaf powder diets. Our results indicate that these maize germplasms are resistant to all three Diatraea spp. The procedures used to obtain an adequate number of southern corn stalk borer neonates from field-collected diapausing larvae for the laboratory bioassay are discussed.