S. R. Dhaka
Agricultural Research Sub Station, Diggi, Tonk, Rajasthan (India)
E-mail: srdhaka@gmail.com
Abstract : The toxicity of spray schedules was evaluated against three predators which revealed that higher population of spider, chrysopa and coccinellids were recorded in spray schedule S2 (all the five sprays of Btk), S1 (all the five sprays of azadirachtin), S5 (all the five sprays of cow urine 5 %) and S6 (all the five sprays of cow urine 10 %) indicating their low toxicity. The population of predators in these schedules was comparable to that of control. The treatments of synthetic insecticides viz., methyl demeton, monocrotophos, deltamethrin, endosulfan, alphamethrin and imidacloprid proved highly toxic to all the three predators resulting in their low population. The endosulfan was found less toxic to the predators than all other synthetic insecticides.
Keywords : Relative toxicity, Spray schedules, Natural enemies, Cotton
REFERENCE
Adilov, Z. K.; Khakmov, A.; Babebekov, K. and Agzamova, Kh. K. (1990). Influence of microbial preparations on the entomophages of the cotton agrocoenosis. Zaschita Rastanii, 7: 34.
Deole, S. A.; Bodhade, S.N.; Mahajan, L. B.; Deotale, V. Y. and Sharnagat, B. K. (2000). Residual toxicity of some pesticides used in cotton pest management against a chrysopid, (C. carnea). J. Soils and Crops, 10 (2): 279-281.
Dhawan. A. K.; Simwat, G. S. and Madan, V. K. (1994). Impact of sysnthetic pyrethroids on arthropod divercity and productivity of upland cotton, Gossypium hirsutum. J. Cotton Res. Dev., 7 (1): 81-89.
Dhawan. A. K.; Simwat, G. S.; Madan, V. K. and Sindhu, A. S. (1990). Impact of different insecticides on target and non target pests and productivity of cotton in different varieties of Asiatic cotton Gossypium arborium L. J. Cotton Res. Dev., 4 (1): 84-92.
El-Ghareeb, A. M. (1989). Selective toxicity and development of insecticide resistance in Spodoptera littoralis (Boisd.) and Coccinella undecimpuctata L. Assiut J. agric. Sci., 20 (3): 351-365.
Fayad, Y. H. and Ibrahim, A. A. (1988). Impact of successive insecticidal applications at different interval periods on the number of predators in cotton fields. Bull. Ent. Soc. Egypt, Eco. Series, 15: 47-58.
Hao, X.C.; Hu, F. Q. and Fang, C. Y. (1990). Preliminary study on the reaction of Coccinella undecimpuctata to insecticides at different development stages. Natural Enemies of Insects, 12 (2): 62-65.
Kakkar, A. R. (1981). Pesticides market for cotton in Punjab – Farmer’s Viewpoint. M. Sc. Thesis, PAU, Ludhiana, India 60 pp.
Mansour, F. (1987). Spiders in sprayed and unsprayed cotton fields in Israel, their interactions with cotton pests and their importance as predators of the Egyptian cotton leaf worm, Spodoptera littoralis. Phytoparsitica, 15(1):31-41.
Schmutterer, H. (1996). Side effect of neem products on insect pathogens, predators and parasitoids. In: Proceedings International Neem Conference (February 4-9), The University of Queensland, Gatton College, Australia, p.55.
Yadav, D. N. and Patel, A. R. (1993). Effect of some botanical insecticides on oviposition of Chrysopa scelestes and their ovicidal action. In: National Symposium on Botanical pesticides in Integrated Pest Management, January 20-21, Rajahmundry, pp. 166-169.