Investigation on the Effects of some Pesticides and Plant Extracts on Life Table of Chrysoperla carnea (Neu.: Chrysopidae)

Demographic toxicology is a common method for an investigation of the sub lethal effects of pesticides on natural enemies. The present study was conducted to evaluate the side effects of the extracts of Calotropis procera (Willd.) R. Br. (Asclepiadaceae), Teucrium polium L. (Labiatae), Fumaria parviflora Lam. (Fumariaceae) and Thymus vulgaris L. (Labiatae) in comparison with three pesticides: Hexaflumuron, Pymetrozin and Spirodiclofen on life table parameters of Chrysoperla carnea (Stephens) under controlled conditions. One hundred and fifty four fresh eggs were treated through dipping method. Results showed significant differences (p≤0.01) among treatments for Gross Reproductive Rate (GRR), net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), intrinsic birth rate (b) and Doubling Time (DT), while it showed no significant difference for intrinsic death rate (d) and mean generation time (T) parameters. The highest to lowest gross reproductive rates were observed in Pymetrozin, Spirodiclofen, T. polium, C. procera, T. vulgaris, hexaflumuron and F. parviflora respectively. The maximum of net reproductive rate, finite rate of increase and intrinsic birth rate were observed in Pymetrozin while a minimum in F. parviflora. Thus, the immunity was observed in pymetrozin, C. procera, T. polium and T. vulgaris respectively while Hexaflumuron and T. vulgaris showed the highest inhibiting effect on stable population growth parameters. Two extracts C. procera and T. polium are the most suitable choices, because of their immunity on C. carnea as a biological control agent.