Abstract:
In this research, we isolated the pathogenic strain, KB512, of entomopathogenic
fungi Beauveria bassiana from soil and insects, which produced aerial and
submerged conidia and blastospores in the laboratory conditions. We investigated
the best conditions for the production and utilisation of the spore suspension to
spray Aphis fabae and Bemisia tabaci, which are two important pests in Kerman
province (Iran). The pathogenicity test was carried out with direct spray. To
bioassay the isolates, three concentrations of the spore suspension were prepared
as follows: 1 6 10 8 , 1 6 10 7 and 1 6 10 6 conidia/ml. The pests were sprayed by
aerial conidial suspension, which was prepared by 0.01% Tween-80 in distilled
water, and the controls were sprayed by 0.01% Tween-80 in distilled water. After
spraying the pests, the plates were incubated at 25 + 18C and 80% of relative
humidity. Then the treated pests were monitored every day for the fungal growth
and mortality. After nine days, mortality in the insects treated with 1 6 10 8
conidia/ml was 42.4% and 34% for Aphis fabae and Bemisia tabaci, respectively.
Nowadays, biological control methods, especially the use of microbial agents, are
believed to be environmentally friendly and safe for non-target organisms.
Therefore, such biological agents can be mass produced to control the pests.
