Field experiments were conduced in 2001/02 and 2002/03 sugar-beet
seasons at Sakha Agric. Res. Station aiming to study the efficacy of the bacterium,
Bacillus thuringiensis (Beri.) and the fungus, Beauveria bassiana (Bals.) against
some sugar-beet insects. Insect population of sugar-beet mining moth, Scrobipalpa
ocel/alella (Boyd.) W when Dipel 2x was applied at a rate of 2.5 g/1. in season 2001/02 and 2002/03,
reSjlecitJvey. More reductions were recorded using the fungus (Biofly) at a rate of 3 x
10 conidialml which gave 43.63 and 47.91%, twenty days after treatment in the two
seasons, respectively. Reduction in the number 0 f I arvae and pupae 0 f the s ugar-
beet fly, Pegomyia mixta (ViII.) were 37.26 and 47.75 by using Dipel 2x while,
applying the plants by the fungus gave more reduction, 42.27 and 57.16%, in season
2001/02 and 2002/03, respectively. However, no significant differences in insect
reductions were found between the t.VQ in biocides. Field experiments indicated that
B. thuringiensis (Dipel 2 x) and B. bassiana (Biofly) could be used efficiently against
S. ocel/atel/a and P. mi)(fa in sugar-beet fields. Obtained results clearly indicated that the tortoise beetie, Cassida vittata
(ViII.) is not sensitive to B. thuringiensis and B. bassiana throughout the period 0 f
study. Spraying of 8. thuringiensis gave 14.91 and 16.42% reduction and B. oessiene
gave 22.53 and 19.97% reduction in the two seasons, 2000/02 and 2002/03,
respectively.