NATURAL REGULATION OF WHITE GRUB (HOLOTRICHIA SP, SCARABIDAE) BY BIRDS IN AGROECOSYSTEM

The white grub (Holotrichia sp: Scarabidae) is an important subterrane an pest damaging root systems of several crops. Experiments conducted during 1985 and 1986 showed that at least 14 species of birds picked u p the grubs exposed during ploughing operation. The important bird pre dators were mynas Acridotheres tristis (Linnaeus) and Acridotheres gin ginianus (Latham), crows Corvus splendens (Vieillot), Corvus macrorhyn chos (Sykes), drongo Dicrurus adsimilis (Hodgson) and cattle egret Bub ulcus ibis. The birds were found to reduce 45 to 65% grub population d uring 3 subsequent ploughings. The plant stand of second crop raised i n bird exposed field was higher in experimental plot compared to the c ontrol. The number of birds attracted to the plough was not consistent with the density of grubs exposed but oh many extraneous factors. Fac tors affecting the extent of bird predation were presence of insectivo rous birds in the surroundings, proximity to their breeding sites and timing of ploughing. White grub control by birds is economically cheap er and environmentally safe compared to the chemical control.