Evaluation of the Bio-insecticidal Effects of Three Extracts on the Larvae of the Green Lacewing Chrysoperla carnea (Stephen) under the Laboratory Conditions

ABSTRACT

Aims: To control aphids without the misdeeds of the chemical insecticides. To make sure of the harmlessness of three bio-aphicides. Study Design: Experimental device in complete random block with three replications. Place and Duration of Study Laboratory of bio-insecticidal entomology, Regional Center of Agricultural Research of Kenitra, INRA- Morocco and the Biodiversity and Natural Resources Laboratory of Sciences Faculty, Ibn Tofail kenitra, morocco. The experiments were done between March and December 2017. Methodology: The present study highlighted the lethal and sublethal effects of three bio-aphicides plants collected from the Gharb region of morocco Capsicum frutescens, Nerium oleander and Melia azedarach, tested in five concentrations of their plant material against Chrysoperla carnea larvaes. Adding to these concentrations, two controls were used one without any treatment (blanc) and another treated with a chemical insecticide (Deltamethrine). Results: The obtained results indicated that the aqueous extract of the Nerium oleander was harmful to the larvae of the Chrysoperla carnea. Indeed, the insecticidal activity of different concentrations increased with the exposure time, reaching about 10; 16 and 20% of mortality, respectively by applying 10; 15 and 20 g/20 ml after three days of exposure. However, low concentrations of 2 and 5 g/20 ml caused no effect whatever the duration of exposure. Also, the corrected mortality rate caused by the aqueous extract of Nerium oleander, at the concentrations tested is much lower than that caused by the insecticide Deltamethrin. Conclusion: Nerium oleander plant is harmful to the larvae of the Chrysoperla carnea at concentrations of 10; 16 and 20%. At these concentrations, the aqueous extracts of hot pepper and melia are not haurmful to the larvae of the green lacewing, so they can be recommended as a biological insecticide. Moreover, other works on these two extracts are outstanding in our laboratory.