Adults are most active at night when the temperature exceeds 27 degrees C, relative humidity is high, and there is little air movement. Such conditions are optimal for mating and oviposition. Females produce about 200 eggs. Adult longevity under field conditions is estimated at about 10 days. Natural Enemies Several natural enemies of lesser cornstalk borer are known, though they are not thought to be major determinants of population trends.
Pathogens are commonly present in lesser cornstalk borer populations.
The most important pathogen appears to be a granulosis virus, but a Beauveria sp. Weather Lesser cornstalk borer seems to be adapted for hot, xeric conditions, and therefore tends to be more abundant and damaging following unusually warm, dry weather. Mack et al. Borer-days is calculated as the sum of days during the growing season in which the temperature equals or exceeds 35 degrees C and the precipitation is less than 2.5 mm, less the number of days in which the temperature is less than 35 degrees C and the precipitation equals or exceeds 2.5 mm. Thus, it is the sum of the number of hot, dry days less the number cooler, wetter days.