L-Tryptophan as an Ovipositional Attractant for Chrysoperla carnea (Stephens) (Neuroptera:Chrysopidae)

Laboratory and field cage experiments were conducted to select the best kairomone as an ovipositional attractant for Chrysoperla carnea (Stephens). Acid hydrolysed L-tryptophan (15 days after storage) was found to be highly attractive to the males and females of C. carnea in no choice method, using wind tunnel method and in multiple choice method using the kairomone treated filter paper. Pure commercial honey, 25 per cent and 50 per cent honey solutions were attractive in no choice method but not in the multiple choice method. Highest number of eggs were laid on the filter paper sprayed with 15 days old L-tryptophan in laboratory study. However, in the field cage studies, only 3 day old L-tryptophan recorded highest oviposition on cotton plants treated with the kairomones, probably the breakdown product of L-tryptophan is not effective in long range if stored beyond 7 and 15 days. Possibility of using L-tryptophan in the field is discussed.