LEKHASHARMA, SHIVANI2019-02-062019-02-062018Sharma. S, and lekhahttp://krishikosh.egranth.ac.in/handle/1/5810093897Host preference studies in Rangeeni strain of lac insect, Kerria laccaHost preference studies in Rangeeni strain of lac insect, Kerria lacca (Kerr) Shivani Sharma* Dr. Lekha The investigations on host preference and life cycle of Rangeeni strain of lac insect on ber, pigeonpea and flemingia were carried out at the lac insect gene bank and lac laboratory, situated at Department of Entomology, Rajasthan College of Agriculture, MPUAT, Udaipur during Katki season, 2017 with an aim to study the parameters of host preference viz., initial and final density of settlement (crawlers per sq.cm), initial mortality (%), density at crop maturity (number of female cells per sq.cm), broodlac ratio, female cell size (mm), weight of female cell and resin (mg) and stick lac yield (kg) and to evaluate life cycle parameters of lac insect viz., duration of pre-sexual stages (days), duration of male emergence (days), sex ratio (per cent male insect), life period of female lac insect (days), fecundity (per female cell) and total scrappedlac yield (kg). The initial density of settlement of first instar crawlers on host plants varied in different parts of plants which ranged from 32-114, 23- 120 and 30-110 crawlers per sq.cm with the mean initial per cent mortality 10.30, 9.70 and 7.97; 12.49, 11.83 and 11.49 and 14.54, 14.43 and 13.17 per cent on upper, middle and lower parts of ber, flemingia and pigeonpea respectively during Katki season, 2017. The final density of settlement first instar crawlers ranged from 37-112, 20-110 and 20-100 crawlers per sq.cm on upper, middle and lower portion of ber, flemingia and pigeonpea respectively. The density of female cells at maturity ranged from 2-9, 1-8 and 1-7 cells per sq.cm on ber, pigeonpea and flemingia. The broodlac ratio 0.186, 0.15 and 0.19; 0.05, 0.06 and 0.07; 0.010, 0.011and 0.009 was recorded in three sets of experiments each of ber, pigeonpea and flemingia. The mean female cell size, weight of female cell, resin weight and sticklac yield were recorded as 2.13, 1.81 and 1.47 mm; 22.54, 19.39 and 17.15 mg; 20.92, 17.82 and 15.57 mg and 3.69, 1.08 and 1.73 kg in ber, flemingia and pigeonpea respectively during Katki season, 2017. The mean duration of pre-sexual stages of Rangeeni strain lasts 46.77, 47.53 and 48.93days from the inoculation of broodlac with 11.50, 12.73 and 13.27 days mean duration of male emergence in ber, flemingia and pigeonpea respectively and 10.51, 11.02 and 11.17; 11.33, 13.23 and 13.59; 10.78, 11.17 and 11.86 per sq. cm of per cent male in upper, middle and lower portion of host plant in three set of experiment respectively. The total life period of Rangeeni strain of lac insect in Katki crop season on ber, flemingia and pigeonpea was recorded 115, 118 and 120 days respectively and fecundity of female cell was recorded 443.37, 387.70 and 336.07 crawlers (per female cell) in ber, flemingia and pigeonpea respectively. The mean of scrappedlac yield recorded 0.74, 0.35 and 0.22 kg for ber, pigeonpea and flemingia respectively.ennullThesis