SEASONAL INCIDENCE OF TETRANYCHUS-CINNABARINUS (BOISD) (ACARINA, TETRANYCHIDAE) AND LOSS OF YIELD IN OKRA CROP

Seasonal incidence of Tetranychus Cinnabarinus (Boisd.) (Acarina: Tetr anychidae), recorded on two varieties of Okra, Parbani Kranti and Pusa Sawani, during the rainy and winter season crops revealed that the in cidence started within a month of sowing. The population (recorded on 45 x 2 cm. sq. leaf surface area) on Parbani Kranti variety showed ste ady build-up and reached high levels during the second half of August, 1994 (996) in rainy season crop and the second half of December, 1994 (1056) in winter season crop respectively. On Pusa Sawani the maximum population was recorded in the second half of December (1 106) during winter crop season and the second half of August (1012) in rainy seas on when the crop was 3-4 months old. It remained at a moderate level t hereafter and at the end of crop season the population trend was on th e decrease. The incidence trend was almost similar on both the varieti es, although the mite population recorded was more on Pusa Sawani than on Pusa Kranti. The experiments conducted under semi-field conditions on Parbani Kranti showed a loss of 6.8 percent in yield amounting to Rs. 8001 per ha. @ Rs. 3 per kg. in the rainy season and 8.5 per cent in yield amounting to Rs. 5000 per ha. @ Rs. 5 per kg. in the winter s eason crop due to mites only.