period of reproduction of A. gossypii (Fig. 1). Aphids may come in
contact with conidia on the surface of leaves; their presence due
either to conidiation from endophytic colonies or from deposition
of air-borne spores. When conidia of B. bassiana were observed on
the surface of corn leaves (Bing and Lewis, 1991), the authors
suggested that the conidia may have settled from windblown
inocula or could have developed frommycelium within the leaf.We
have seen conidiomata of L. lecanii emerging through stomata of
living leaves. Indeed, we were able to isolate the fungus from the
surface of the leaf 28 d after inoculation (Pampapathy et al., 2010).
However, conidiation of endophytic Diaphorte phaseolorum (Cooke
and Ellis) Sacc took place once the host plant was dead (Schwarz
et al., 2004) and this delay may occur in entomopathogens in
specific hosts. Whether the entomopathogenic fungi complete their
life cycle inside the living plant remains to be determined.
The pathogenicity of L. lecanii and B. bassiana to aphids has been
demonstrated by spraying aphids with conidia and following the
interaction under laboratory conditions. Insects may be colonized