~ 887 ~ Journal of Entomology and Zoology Studies 2017; 5(3): 887-890 E-ISSN: 2320-7078 P-ISSN: 2349-6800 JEZS 2017; 5(3): 887-890 © 2017 JEZS Received: 03-03-2017 Accepted: 04-04-2017 Jitendra Nagar Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India SK Khinchi Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India BL Naga Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India SL Sharma Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India Akhter Hussain Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India Anita Sharma Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India Correspondence Jitendra Nagar Department of Entomology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, India Effect of abiotic factors on Incidence of sucking insect pests and their major natural enemies of Okra Jitendra Nagar, SK Khinchi, BL Naga, SL Sharma, Akhter Hussain and Anita Sharma Abstract The present research was aimed to study the seasonal incidence of major sucking pests and their natural enemies on okra, Abelmoschus esculentus (L.) Moench under field conditions at Department of Entomology, S.K.N. College of Agriculture, Jobner, Rajasthan during kharif, 2014. The crop revealed that two sucking pests viz., jassid, Amrasca biguttula biguttula (Ishida) and whitefly, Bemisia tabaci (Genn.) appeared as major sucking pests. The incidence of jassid and whitefly was first commenced in the second week of August and reached to peak (16.50 jassids and 18.80 whiteflies per three leaves) in the third week of September, at 34.5 0 C maximum temperature, 22.1 0 C minimum temperature, 71.0 per cent relative humidity, thereafter, the insect population started declining. The correlation studies revealed that the infestation of jassid and whitefly on okra crop showed non-significant correlation with maximum temperature (r = -0.02 and -0.03), minimum temperature (r = 0.30 and 0.33) and rainfall (r = 0.45 and 0.48), while positive significant correlation with relative humidity (r = 0.65 and 0.64) and predatory lady bird beetle (r = 0.98 and 0.97). The predatory lady bird beetle, Menochilus sexmaculatus Fab. was also recorded during the crop season. The population of lady bird beetle was first recorded in the third week of August which gradually increased and reached to peak (4.70 beetles/ five plants) in the third week of September, thereafter, their population started to decline. The correlation studies showed a non- significant correlation with maximum temperature, minimum temperatures and rainfall, while, significant correlation with relative humidity. Lady bird beetles showed a significant effect on the pest species. Keywords: Abiotic factors, sucking insect pests, Natural enemies and okra, A. esculentus Introduction Okra [Abelmoschus esculentus (L.) Moench] commonly known as Bhindi or lady’s finger (family: Malvaceae) is a popular fruit vegetable crop due to its high nutritional and medicinal values. In India, it is cultivated throughout the country for its immature tender fruits. The crop occupies an area over 532.66 thousand hectares with an annual production to the tune of 6346.37 thousand metric tonnes. In Rajasthan, it is grown in an area of 3.95 thousand hectares with an annual production of 12.27 thousand metric tonnes (Anonymous, 2013-14) [1] . It is attacked by a number of insect pests right from germination to harvesting, viz., jassid, Amrasca biguttula biguttula (Ishida); aphid, Aphis gossypii (Glover); whitefly, Bemisia tabaci (Genn.); shoot and fruit borer, Earias insulana (Boisd.), Earias vittella (Fab.); leaf roller, Sylepta derogata (Fab.); red cotton bug, Dysdercus koenigii (Fab.); mite, Tetranychus cinnabarinus (Boisd.); green plant bug, Nezara viridula (Linn.); blister beetle, Mylabris pustulata (Thunb.) and green semilooper, Anomis flava (Fab.). Among these pests, jassid, A. biguttula biguttula and whitefly, B. tabaci are most important sucking insect pests of okra in Rajasthan (Dangi and Ameta, 2005; Meena and Kanwat, 2005) [3, 9] . The jassids suck the cell sap from lower surface of the leaves and inject toxic substance resulting in curling of leaves, as a result of which the plant growth is retarded. The severe infestation of the pest causes burning of leaves which fall latter and results in 40-60 per cent decrease in yield. The whitefly transmits viral diseases from diseased to healthy plants as a vector (Narke and Suryawanshi, 1987) [11] . To minimize the losses caused by insect pests in okra crop, the weather conditions prevailing in a region play an important role in occurrence and subsequent build-up of pest population. As such the studies were undertaken the effect of abiotic factors on incidence of sucking insect pests and their major natural enemies of okra.