Comparison of functional response of two and one individual female predator, Hippodamia variegata Goeze (Coleoptera: Coccinellidae) to different densities of Aphis gossypii Glover (Hemiptera: Aphididae) under laboratory conditions

Abstract : The functional response of two and one individual female predator, Hippodamia variegata Goeze (Col.: Coccinellidae) to different densities of third instar nymphs of Aphis gossypii Glover (Hem.: Aphididae) were studied in a growth chamber (25˚C, 65 ± ¬¬5% RH and a photoperiod of 16L: 8D h) on the black eyed bean, Vigna unguiculata. Each experiment was replicated ten times. Using the logistic regression, a type II functional response was determined for two and one female ladybeetle. The searching efficiency (a') and handling times (Th) of the female adults by using Nonlinear regression were estimated 0.003± 0.000424 h-1 , 0.106 ± 0.00441 h, 0.122 ± 0.021 h-1 and 0.105 ± 0.048 h for two and one individual predator, respectively. The voracity of female H. variegata in both cases had a similar trend showing a direct dependence on prey density (R2= 0.9976, 0.9991). This study revealed that two individual predator reduced the searching efficiency of H. variegata
Keyword : Hippodamia variegata, Aphis gossypii, functional response, two individual predator
Author(s) : , S. D. Dehkordi, A. Sahragard, J. Hajizadeh
Downloads : 1250


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