SOYBEAN GENOTYPE EFFECTS ON BIGEYED BUG FEEDING ON CORN-EARWORM IN THE LABORATORY

Corn earworm, Helicoverpa zea (Boddie), is a serious pest of many crop s, including soybean, Glycine max (L.) Merr. This study was conducted to determine whether or not plant pubescence could be used to enhance predator activity. The influence of plant pubescence or insect resista nce of soybean on predation of corn earworm eggs by the bigeyed bug, G eocoris punctipes (Say), was investigated in the laboratory. Bigeyed b ug adults were allowed to reed on corn earworm eggs that were placed o n foliage of soybean genotypes isogenic for dense, normal, or no pubes cence, and on genotypes susceptible or resistant to foliar feeding ins ects. Percent egg puncture by males was similar on all foliage types w hether or not choices were offered. Females punctured significantly (P < 0.05) more eggs on normal leaflets in a no choice situation. Signif icant differences (P > 0.05) were not detected in percent egg puncture on soybean genotypes resistant to foliar feeding insects as compared with susceptible genotypes ('Centennial' and 'Davis'). Development of soybean cultivars with reduced pubescence, which is less preferred by corn earworm for oviposition and/or foliar feeding, will probably not influence this beneficial predator, since egg predation was not advers ely affected by plant pubescence or insect resistance under laboratory test conditions.