Feeding and develoment of european corn borer and southern armyworm larvae on U.S. inbred and caribbean maize genotypes

Abstract

DIMBOA is an aglucone that occurs in some maize genotypes and has been known as a resistance factor of corn to several pathogens and insects. In this study, variable concentrations of DIMBOA in several corn genotypes at different plant heights as well as dif­ ferent plant parts were observed. In B 49, San Juan and DIMBOALESS genotypes, the concentration of DIMBOA declined as the plants grew taller. DIMBOA concentrations were generally highest in the leaves and then in decreasing order of concentration, in the whorl and stalk. Feeding and developmental studies of European corn borer on selected maize genotypes were conducted under field and greenhouse conditions. Apparently, corn plant resistance (DIMBOA and a non­ DIMBOA mechanism in San Juan) was largely expressed during the first instar feeding period. As the larvae move into other parts of the plant, genotypic-specif lant resistance, if any, to larval development becomes more variable.