The persistence of infectivity of conidia of the aphid pathogen Erynia neophidis on leaves in the field

Conidia of the aphid pathogen Erynia neophidis inoculated on to bean leaves in the field in 1980, 1981 and 1982, retained some infectivity for pea aphids for at least 14 days. Decline in infectivity occurred linearly with time. Inocula on leaves near the base of plants remained infective longer than those on leaves near the top and those on the abaxial surface remained infective for longer than those on the adaxial surface. Infectivity persisted longest in 1981 when conditions were coolest with least sun.