Handling time and predation efficiency of certain insect predators on cotton aphid, Aphis gossypii Glover

The predation efficiency of Chrysoperla carnea (Stephens), Coccinella undecimpunctata Linn. and Coccinella septempunctata Linn. larvae on Aphis gossypii (Glover) nymphs was studied under laboratory conditions. Also, handling time of prey by all larval instars of the three predators was calculated. Handling time (Ht), the time needed by Ch. carnea to consume a prey of A. gossypii was 70.00, 30.56 and 28.50 minuets per one aphid for 1 st , 2 nd and 3 rd instars, respectively. However, it was 74.54, 34.56, 22.69 and 18.85 minutes per one aphid for 1 st , 2 nd , 3 rd and 4 th instars of C. undecimpunctata respectively. Also it was 60.91, 27.61, 20.17 and 17.43 minutes per one aphid for 1 st , 2 nd , 3 rd and 4 th instars of C. septempunctata respectively. The total and daily consumption, also the duration of all larval instars of the three predators were estimated. These results showed that, the handling times of predators are a good indicator of the predation rate and could be used on the biological control of cotton aphid program.