Toxic effects of five compounds, Bacillus thuringiensis kurstaki, Abamectin, Fipronil,
Pyriproxyfen and Beauveria bassiana were evaluated on the green lacewing, Chrysoperla carnea
under laboratory conditions by direct and indirect techniques. Indirect treatment was dependent on
applying each of the tested compounds on eggs of Sitotroga carealella, then feeding C. carnea larvae
on the treated eggs. Chrysoperla carnea, larval mortalities were 6.76, 26.67, 15.83, 33.33 and 26.66
% 7 days after feeding on eggs treated with B. thuringiensis, Abamectin, Fipronil, Pyriproxyfen and
B. bassiana, respectively, compared to 6.67 % among the control larvae . Larval durations increased
from 7.67 days in control to, 11.0, 9.33, 7.93, 9.03, 9.67 days for the treated larvae, respectively.
Pupation rates were 40, 46.67, 0.0, 0.0 and 40 % also, adults, emergence rates were 33.34, 28.57, 0.0,
0.0 and 66.67 %, respectively opposed to 93.34 and 92.86 % for the control. Direct treatments were
made by direct spraying on C. carnea eggs with the recommended concentration of each of the five
compounds. The highest hatchability percentage was 100 % in the control while the lowest was 12 %
in Pyriproxyfen treatment. Also the longest incubation period was 5.33 days in B. thuringiensis
treatment, while the lowest was 2.8 days in the control. Larval mortality was highest (82.5 %) in
Fipronil, while the shortest 6.67 % occurred with B. thuringiensis treated eggs compared with 6.67 %
in the control. Pupal mortality was highest (100 %) in Abamectin and Fipronil treatments, while it
was the lowest (15 %) in B. thuringiensis treatment compared with 11.76 % in the control. |
