Abundance of Pest Complex of Okra in Relation to Abiotic and Biotic Factors

Major insect pests of okra viz., leafhopper, (Amrasca biguttula biguttula); whitefly, (Bemisia tabaci); red spider mite, (Tetranychus cinnabarinus) and fruit borer, (Earias vittella) damaged heavily during the kharif seasons. Leafhopper and whitefly occurred from last week of July. The infestation of okra fruit borer was observed during middle of August, whereas the red spider mite appeared during 1st week of September. Peak incidence of leafhopper (217.00 nymphs/15 leaves), whitefly (28.90/15 leaves), red spider mite (231.10 mites/cm2) and fruit borer (56. 6%) during last week of August, 1st week of August, 3rd week of September and 3rd week of September, respectively. The incidence of leafhopper and fruit borer showed significant negative correlation with relative humidity (r =-0.673 &-0.906) and significant positive correlation with sunshine hours. Positive correlation was observed between the minimum (r = +0.994) and mean temperature (r = +0.889) with the density count of whitefly, whereas fruit borer damage was significant negatively correlated with evening relative humidity (r =-0.862). Among biotic factors viz., coccinellids (r = +0.874) and spiders (r = +0.907) there was significant positive correlation with leafhopper population, whereas the fruit infestation was significant negatively correlated with coccinellids (r =-0.911) and spiders (r =-0.923).