Resistance in common bean (Phaseolus vulgaris) to Lygus hesperus (Heteroptera: Miridae)

Thirty-eight selected acquisitions of P. vulgaris (L.) were evaluated for resistance to the lygus bug, L. hesperus Knight, a major pest of common beans in the western United States. Estimates of gross increase, ovipositional preference, nymphal development, and survival of lygus bugs on those cultivars were used as parameters to identify resistant germplasm and general mechanisms involved in resistance. The assessment of resistance was dependent upon counting newly hatched nymphs as a measure of oviposition. Results suggest that at least two general mechanisms function to provide resistance: nonpreference by interference with oviposition and antibiosis by induction of reduced nymphal growth and survival. These findings will help in selection of germplasm for breeding common beans resistant to L. hesperus .