Division of Transfer of Technology, Indian Lac Research Institute, Namkum, Ranchi-834 010, Bihar, (India).
1Division of Lac Production, Indian Lac Research Institute, Namkum, Ranchi-834010, Bihar, (India).
Naturally occurring eleven lac insect stocks of Kerria spp. were studied on ber, (Zizyphus mauritiana) for their performance with respect to ten productivity linked characters, viz., density of settlement, per cent initial mortality, sex-ratio, number of females/cm2 at sexual maturity, live cell weight, dry cell weight, resin/female, number of females at crop maturity, life period, and sticklac productivity in terms of sticklac output/meter/day. Estimates of phenotypic coefficient of variance, genotypic coefficient of variance, heritability and genetic advance calculated were found to be in the range of 18.26 to 61.31, 18.00 to 58.92, 0.57 to 0.99, and 5.65 to 14.99, respectively. The productivity of lac ranged from 0.214 to 0.670 g/day/meter in the case ofstock nos. LR-5101 and LR-5316, respectively. Of the former aforesaid nine parameters, resin output per female was the highest and sex ratio the lowest value of genotypic correlation coefficient to the extent of 0.9889 and 0.0630, respectively, with productivity of lac.
