Side effect of some Neem products on natural enemies of Helicoverpa (Trichogramma spp.) and Chrysoperla carnea

Abstract

The present work was conducted to evaluate the side effect of Neem products as natural insecticide on some of natural enemies of Helicoverpa armigera Hüb. (Trichogramma spp. and Chrysoperla sp.). The work is divided into laboratory and greenhouse experiments. The laboratory experiments dealt with the side effects of Neem products: NeemAzal-T/S, NeemAzal Blank, NeemAzal PC 05 and NeemAzal PC 05 Blank on Trichogramma spp. and C. carnea (Stephen). Neem concentrations: 2, 1, 0.5 and 0.25% were arranged in a completely randomized block design and each treatment was replicated at least six times. Parasitism and emergence rates of T. pretiosum (Riley) and T. minutum (Riley), and predation rates of C. carnea and its longevity were investigated. The greenhouse experiments dealt with the side effects of Neem products on parasitism rates of T. pretiosum and T. minutum on three different cotton cultivars. There were no serious side effects on parasitism and emergence rates of Trichogramma spp. and on efficiency of Chrysoperla. Similarly, Neem products achieved a good control of H. armigera in laboratory and greenhouse. Therefore, Neem products are recommended for controlling Helicoverpa, and are compatible with mass release of Trichogramma and Chrysoperla for organic cotton production. Future field experiments are suggested to further elucidate the effects of Neem on H. armigera and its natural enemies.

Keywords:

• Neem
• Helicoverpa
• Trichogramma
• Chrysoperla
• laboratory
• greenhouse

Acknowledgments

My thanks go to Dr Kleeberg for providing us the Neem products for this study, and also to all those who contributed in any way to this work, but are not mentioned here.