~ 1374 ~ Journal of Entomology and Zoology Studies 2019; 7(3): 1374-1380 E-ISSN: 2320-7078 P-ISSN: 2349-6800 JEZS 2019; 7(3): 1374-1380 © 2019 JEZS Received: 23-03-2019 Accepted: 25-04-2019 G Venu Gopal Department of Entomology, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, Telangana, India K Vijaya Lakshmi College of agriculture, Palem, Nagarkurnool, Telangana, India B Sarath Babu National Bureau of Plant Genetic Resources, Rajendranagar, Hyderabad, Telangana, India P Kishore Varma Regional Agricultural Research Station, Anakapalli, Andhra Pradesh, India Correspondence G Venu Gopal Department of Entomology, College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, Telangana, India Screening of chilli accessions against chilli thrips Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) G Venu Gopal, K Vijaya Lakshmi, B Sarath Babu and P Kishore Varma Abstract Selection of an efficient, simple and accurate screening method is important in a varietal evaluation programme. The objective of this study was to evaluate reaction of chilli accessions to thrips infestation. Chilli thrips Scirtothrips dorsalis population number and per cent leaf curl were most suitable in separating the difference of chilli accessions. The accessions viz., EC-596952, EC-390033 and EC- 391082 were least preferred by the insect pest and colonized few thrips (43.40 to 45.20 thrips / 10 terminal) and two accessions viz., EC-599976 and EC-599994 were highly susceptible to the pest incidence. The leaf curl index was taken on 50, 70 and 90 days after transplantation. The accessions such as EC-596952, EC-391082 and EC-390033 showed least per cent leaf curl index whereas, accessions EC- 599976 and EC-599994 recorded highest per cent leaf curl index. Keywords: Chilli thrips, leaf curl index, accessions, Scirtothrips dorsalis, leaf terminal 1. Introduction Chilli is an important commercial crop of India, cultivated for vegetable, spice and industrial (oleoresin and capsaicin extraction) purposes [1] . Over 20 insect species in chillies from India of which thrips (Scirtothrips dorsalis), mites (Polyphagotarsonemus latus) and aphids (Aphis gosypii and A. craccivora) are among the most damaging pests [2] . Among the sucking insect pests, chilli thrips S. dorsalis Hood (Thripidae: Thysanoptera) is considered as the most serious and important pest as it attacks the crop from nursery till the harvest of the crop. Chilli thrips multiply appreciably at a faster rate during dry weather periods and causes yield loss of 30 to 50 per cent in South India [3] and sometimes may cause more than 90 per cent yield reduction [4] . Due to variation in the agro climatic conditions of different regions, the nature and extent of damage caused by thrips varies. Environmental factors play an important role in determining the seasonal abundance and damage caused by the insect pests. Hence it is necessary to study the influence of various abiotic factors effecting the population fluctuation of thrips species in chilli crop. These studies would give an idea about the peak period of their activity which in turn may be helpful in developing better pest management strategies. Due to mono culture of chilli over a period of time, the pest buildup of S. dorsalis has increased enormously and the farmers are resorting to a minimum of 5-6 chemical sprays. In addition to this the increased pesticidal sprays become a threat to chilli ecosystem causing resurgence of pests and menace to natural enemies. Pesticide residues in chilli are also of great concern for domestic consumption and exports as well. It is therefore imperative to resort to other alternative pest management strategies such as use of resistant varieties. It is important to screen the varieties for resistance/susceptibility to pest infestation. For developing resistant cultivars, the germplasm lines with known sources of resistance should be available so that they can be utilized in the breeding programme [5] . To control these pests, frequent application of excessive and indiscriminate use of several insecticides causes heavy environmental pollution and health hazards along with pest resurgence problems which ultimately increases the cost of cultivation without giving satisfactory production. To overcome this menace, host plant resistance can play a key role in formulating alternative pest management strategies. Therefore, an alternative method by introducing or determining the use of resistant varieties that may contain different chemical substances to detoxify these insect’s attack will be one of main component to be added in IPM as an environmental friendly pest management approaches.