Behavioral Response and Predation Efficiency of Generalist Predator, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) Larvae to Different Webbing Densities of Tetranychus urticae Koch (Acari: Tetranychidae)

The present study aimed to investigate the behavioral response, predation rate, and feeding time of different larval instars of the insect generalist predator, Chrysoperla carnea (Stephens), towards two webbing densities constructed by the two-spotted spider mite, Tetranychus urticae Koch, on Solanum melongena. The behavioral responses of three larval instars of the predator were recorded during the first hour after release. All the larvae exhibited similar web-coping behavior. The predation rate of the 2nd instar feeding on T. urticae motiles and eggs was significantly different across each webbing density treatment. After 24 hours of release, the larvae preyed more on T. urticae eggs across both webbing densities. These findings suggest that C. carnea 2nd instar should be released at the time of initial establishment of the spider mite colony, i.e., at low webbing density, on the host substrate for effective biological control. Furthermore, future bioecological research on insect and mite predators against silk-producing spider mites should also be conducted under the webbing effect.