Tropentag, October 7 - 9, 2008 in Hohenheim "Competition for Resources in a Changing World: New Drive for Rural Development"

Integration of Calneem Oil and Habrobracon hebetor (Say) (Hymenoptera: Braconidae), a Parasitoid of Pyralid Moths, against Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) in Stored Rice

¹Humboldt-Universität zu Berlin, Institute for Horticultural Sciences, Germany
²Federal Biological Research Centre for Agriculture and Forestry (BBA), Germany
³Biological Consultants Ltd., Germany
⁴Caldor Trading Ltd, NIA, United Kingdom
⁵University of Ghana, Crop Science Department, Ghana

Abstract

The worldwide growing demand for 'clean food' and better ecological approaches to pest control has been the stimulus for further research into the use of neem extracts to control stored pests. Calneem is a new commercial product that was extracted from the neem tree (Azadirachta indica). It is an oil extract from pure neem seed kernels collected, crushed and used in Ghana against stored product pest insects. Calneem is a biopesticide produced and marketed in Ghana by AQUA AGRIC Community Projects (AACP). Experiments were carried out in the laboratory to assess the compatibility of calneem oil and the parasitic wasp Habrobracon hebetor against Corcyra cephalonica. 50 ml of cracked rice were placed in 1 l glass jars and 20 last instar larvae of C. cephalonica were added. 10 freshly emerged adults of H. hebetor were introduced into all the glass jars. Treatments comprised control grain without neem, grain treated with only neem, grain treated only with H. hebetor and grain treated with neem and H. hebetor. The calneem oil was applied as mixture in which the oil was dissolved in water using soap as emulsifier. It was applied at four contents (0.5% v/v, 1.0% v/v, 2.0% v/v and 3.0% v/v) Each treatment was replicated four times. The openings of the glass were sealed with a piece of cloth and rubber band and then placed in a growth cabinet (temperature 25°C and 65-70% relative humidity). Progeny emergence was recorded in all the different treatments after 3 weeks. In the samples that were not exposed to neem and H. hebetor, out of the 20 larvae of C. cephalonica almost all developed into adults. The Calneem dosages and H. hebetor significantly reduced the emergence of C. cephalonica in all the treatments compared to the control. Generally, the combination of neem and parasitoids was not more effective compared to one of these two treatments alone. The scope of the presented results will be discussed.

Keywords: Calneem oil, Corcyra cephalonica, Habrobracon hebetor, rice, Sitophilus oryzae, stored product pests

Contact Address: Charles Adarkwah, Humboldt-Universität zu Berlin, Institute for Horticultural Sciences, Lentzeallee 55, 14195 Berlin, Germany, e-mail: lesadarkyahoo.com