~ 678 ~ Journal of Entomology and Zoology Studies 2020; 8(2): 678-681 E-ISSN: 2320-7078 P-ISSN: 2349-6800 www.entomoljournal.com JEZS 2020; 8(2): 678-681 © 2020 JEZS Received: 20-01-2020 Accepted: 24-02-2020 Praveen Kumar M.Sc. Scholar, Department of Entomology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India SP Yadav Assistant Scientist, Department of Entomology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India Krishna Rolania Assistant Scientist, Department of Entomology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India Puneet Ph.D. Scholar, Department of Entomology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India Corresponding Author: Praveen Kumar M.Sc. Scholar, Department of Entomology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India Biology of Cotton Leafhopper Amrasca devastans (Ishida) on Transgenic Cotton and desi Cotton Hybrid Praveen Kumar, SP Yadav, Krishna Rolania and Puneet Abstract Biology of Amrasca devastans (Ishida) on transgenic cotton hybrid, RCH 650 BGII and desi cotton hybrid, AAH 1 cotton was studied in the laboratory of Department of Entomology, CCSHAU, Hisar. The average total nymphal period on RCH 650 BGII (transgenic cotton) lasted for 6.50 ± 0.55 days whereas, it lasted for 7.67 ± 0.52 days on AAH -1 (desi cotton hybrid). The nymphal survival on RCH 650 BGII ranged from 40 to 70 per cent with an average of 56.67 ± 10.33 per cent while it ranged from 30 to 50 per cent with an average of 43.33 ± 8.16 on AAH -1. Nymphal growth index was 8.72 for RCH 650 BGII and 5.65 for AAH 1. Sex ratio of male: female was 1: 0.84 and 1: 0.82 on RCH 650 BGII and AAH 1, respectively. Maximum number of eggs per leaf i.e. 35.20 ± 3.91and 29.60 ± 3.78 were found on August 7, 2016 (32 nd SMW) on RCH 650 BGII and AAH 1, respectively. The maximum average number of eggs in lateral veins were 16.9 ± 3.51 and 12.5 ± 2.46 on RCH 650 BGII and AAH 1, respectively. On August 22, 2016, in lateral veins of RCH 650 BGII had 13.6 ± 2.37 eggs and AAH 1 had 7.5 ± 2.12 eggs which were maximum among other veins. On September 6, 2016 (34 th SMW), maximum average numbers of eggs in sub veins had 6.1 ± 1.79 and 3.7 ± 1.34 number of eggs in RCH 650 BGII and AAH 1, respectively. Keywords: Amrasca devastans, biology, transgenic cotton hybrid, desi cotton hybrid Introduction Cotton (Gossypium spp.) is one of the most important commercial crops playing a key role in economic, political and social affairs of the world. It is commonly known as “white gold” and unanimously designated as “King of Fibres”. It has a global significance and grown for its lint and seed. In India, cotton is cultivated in an area of 12.65 m ha with a production of 37.39 million bales (170 kg/bale) of seed cotton during 2015-16. In Haryana, total area under cotton was 6.39 lakh ha and production was 22.00 lakh bales of 170 kg with productivity 665 kg per hectare [1] . Potential of leafhopper to cause damage depends on its oviposition preference and subsequent population on different cotton cultivars. In India and abroad, hundreds of genotypes of cotton have been screened for leafhopper to find out damage and population dynamics under similar environmental conditions [2] . More than 90% of the cotton cultivated in the country comprises transgenic or Bt cotton (Bollgard II) that expresses Cry1Ac and Cry2Ab toxins of Bacillus thuringiensis (Bt). Prior to the introduction of Bt cotton, whiteflies and bollworms were the major insect pests. After the introduction of Bt cotton, bollworm infestation became negligible, until 2010, during which pink bollworm developed resistance to the Cry1Ac toxin, but jassids, thrips, and whiteflies, however, continued to cause damage [3] . Among the sucking pests, the leafhopper (Amrasca devastans Ishida) became a major concern for the stakeholders. In addition to cotton, it is also found to cause serious damage to okra, cacao, potato, pepper etc. The nymphs and adults of A. devastans suck cell sap and cause ‘hopperburn’ symptoms. About 25% losses in yield are reported [4] . Before planning or executing any management tactic for any pest, the life cycle parameters of the pest must be well understood. To successfully manage any pest it is mandatory to detect or predict the fluctuations in the pest population and this in turn is extremely helpful in identifying the weak link in the life history of the pest. More trichome density and length on mid rib adversely affect the oviposition. Female of cotton leafhopper lays eggs in the mid rib, lateral veins and sub veins of cotton leaves. To study the biology of the pest, it is essential to know the feeding habit, behaviour and duration of different developmental stages which in turn help in its management.