Bean leaf beetles are the principal vectors of bean pod mottle virus (BPMV). Last week we discussed the affects of seed-applied insecticides on bean leaf beetles and whether such insecticides can substitute for an early-season foliar application within a BPMV disease management program. Although there is a positive relationship between bean leaf beetles and BPMV, the effect of chemical control on the disease is different than that for the insect vector. As we discussed last week, a management program that included seed-applied insecticides resulted in improved yield but lower seed quality. Why does this happen and how is BPMV affected?