The development of host plant resistance in dry edible bean against Mexican bean beetle populations

The Mexican bean beetle (Epilachna varivestis Mulsant) has long been a pest affecting both soybean and dry bean crops. These pests live near and in bean fields and overwinter as adults. Adults emerge in the spring, preferring periods of high humidity and oviposit eggs on the undersides of bean leaves in clusters of 40-60. Both larvae and adult Mexican bean beetles injure the leaves and pods of the bean plant, thus reducing marketability. While, some research has examined soybean resistance to E. varivestis, there is little information concerning insect resistance in dry beans. In this study we begin to explore dry bean varieties for resistance to this beetle. Populations of E. varivestis were collected both from Nebraska and  Pennsylvania to test resistance against a greater range of insect genotypes. We have two testable hypothesis: 1) Pennsylvanian E. varivestis populations are less adapted than Nebraska populations to dry beans and 2) dry bean resistance (either antibiosis or antixenosis) exists that conservatively affects E. varivestis populations. Here we present results using standardized bioassay procedures and observe the survival of E. varivestis populations.