Diversity and conservation of natural enemies in peanut ecosystem

Abstract

Peanut is one of the most important oilseed crops in India. Peanut is used as food ingredient and also for edible oil extraction. More than 100 insects have been reported from peanut mainly belonging to the orders Viz., Lepidoptera (Helicoverpa armigera (Hubner)), Spodoptera litura (Fab), Aproaerema modicella (Deventer), Amsacta albistriga (Walker) , Spilosom aobliqua (Walker), Coleoptera (Holotrichia consanguinea, H Serrata, Myllocerus sp), Hemiptera (Aphis craccivora Koch, Empoascakerri Pruthi, Empoasca fabae Harris, Empoasca litchi Paoli, Empoasca facialis Jacobi), Dermaptera (Anisolabis stali (Dohrn)), Isoptera (Microtermes sp. Odontotermes sp. Macrotermes sp) and Thysanoptera (Scirtothrips dorsalis Hood., Thrips palmi Karny., Frankliniella schultzei (Trybom), Caliothrips indices (Bagnall)) .Insect-pests of peanut mainly belong to Lepidoptera and Coleopteran orders, causing economic losses and can be managed using egg parasitoids. Thrips acts as a vector for viral diseases viz., Peanut bud necrosis and Peanut stem necrosis - Hemiptera comprising of leafhoppers and aphids also cause significant damage. Isoptera comprising of termites cause damage in peanuts grown in loose sandy soil. To manage these insect pests in an eco-friendly manner we have to conserve natural enemies mainly, Ladybird beetles which predate on soft-bodied insects like leafhoppers and aphids. Cheilomenus sexmaculata (Fab.) is the most common ladybird beetle found in peanut -. Growing green gram or black gram as an intercrop with peanut crop not only helps in attracting ladybird beetles but also provide refuge to these insects. Both adults and grubs of ladybird beetle feed on sucking pests hence, we can manage to suck pests effectively. Conservation of natural enemies not only helps in managing insect pests but also helps in rescuing the environment from the ill effects of hazardous pesticides which otherwise are used to manage the insect pests.