EFFICENCY OF SOME ACARICIDES ON PREDATION POTENTIAL OF Amblyseius gossypi AND Coccinella undesimpunctata ASSOCIATED WITH SPIDER MITE ON COTTON PLANTS .

Abstract

Abamectin caused the highest decrease in prey eggs consumption (56.25 eggs) comparable to the control through the egg meal of the all days (178.80 eggs during four days). Also, Abamectin was the most effective chemical that caused decrease in adult consumption (consumption (32.55 adult during four days) comparable to the control (73.74 adult) Therefore, Abamectin reduced the adult consumption (5.75, 7.25, 9.25 and 10.50, individ. during the first, second, third and fourth days, respectively) with the percentages of 22.63, 23.35, 28.87 and 31.37 %, respectively. Etoxazole was the least effective compound in this respect, when A. gossypi fed on eggs treatment the average of total consumed eggs were 46.03 during the fourth days successively with the percentages of feeding capacity for each of the fourth days of this predator were 17.48, 28.78, 23.25 and 30.97 %, respectively. While ,when it fed on adult of T. urticae, the average consumption of A. gossypi was 42.05 individ. through fourth days successively (73.74 individ . for control ) with the percentages of 23.18, 19.61, 28.35 and 28.65 %, respectively. Laboratory studies carried out on the ladybird beetle predator showed that, it devoured 189.85 of the two spotted spider mite eggs during the shortest duration of larval stage (11.30 days ) compared with control (376.12 eggs) that was consumed in 10 days all larval instars. The fourth larval instar consumed the highest percentages of T. urticae eggs (37.42%) (treatment). On the other hand, the larvae of C. undicempunctata was fed on T. urticae adult, the duration of larval instars lasted 9.45 days, consumed during 176.75 adults in untreatment. While the treatment by Abamectin, the consumption was 104.05 adults for the four instars during 12.50 days. The 4th instar consumed relatively the highest percentages of individual offered four the fore mentioned mite, as it consumed were 13.21, 18.02, 27.63 and 41.56%, respectively. The coccinellid larval stage was completed in four instars, with a total larval duration of 10.50 days, consumed during these days 148.05 eggs. Also, the percentage of feeding capacity for each of the four larval instars of this predator were 17.73, 23.44, 28.19 and 30.90 %, respectively. Concerning the two spotted spider mite adult, the ladybird consumed 100.10 individ. during 12.24 days for the four larval instars. Thus, the most voracious instar was the fourth instar, that consumed 40.04 % out of total consumed. While the first instar was the least voracious (12.24 % out of total consumed).