In these laboratory tests, D. noxia is readily susceptible
to several isolates of B. bassiana and P
fumosoroseus at doses that are logistically and economically
achievable in the field (unpublished
data). This assay method is quite sensitive, compared
with other published assays, as evidenced by
the narrow range of fiducial limits around the
LCsos,higher slopes of probit regressions, and lower
times to death at comparable doses. It will be
used to evaluate the impact of a range of biotic
and abiotic conditions on aphid susceptibility to
fungi. Studies of the effect of temperature, photoperiod,
relative humidity, host plant variety, insect
age and other factors are under way. Related
field research to achieve effective control of D.
noxia has also been initiated.