Oviposition and survival of leafhoppers and thrips in groundnut genotypes and their host relationships

Pot culture experiments were conducted during kharif and rabi to study the oviposition and survival of leafhoppers and thrips on groundnut under caged conditions. Of the twenty five genotypes/varieties evaluated, CSMG 84-1 and ICGV 86522 (0.6 eggs) recorded lesser number of eggs as against ICG 7237 (2.8 eggs/terminal bud). The resistant genotypes had a mean of 1.27 ± 0.53 eggs, susceptible entries 2.18 ± 0.45 eggs and highly susceptible ones with 2.33 ± 0.33 eggs. The number of eggs laid by thrips ranged from 0.4 (ICG 5240 and ICGV 86522) to 2.0 eggs (TMV-2)/terminal bud. The resistant entries had mean number of eggs- 0.62 ± 0.24, moderately resistant ones- 1.00 ± 0.18, susceptible ones- 1.21 ± 0.41 and highly susceptible ones- 1.63 ± 0.34 eggs. The leafhopper survival was maximum in ICG 7237 (14.00/plant), and minimum in NCAc 343 (2.00/plant). The resistant genotypes recorded a mean survival of 5.17± 2.71 nymphs/plant, whereas, the moderately resistant ones had 8.33 ± 1.37 nymphs/plant, susceptible ones 9.42 ± 1.27 nymphs/plant, and highly susceptible ones with 10.8 ± 1.94 nymphs/plant. The thrips survival varied from 3.00 (ICGV 86522) to 12.00 (TMV-2)/plant, with the mean number of thrips being 4.50 ± 1.04, 6.66 ± 1.96, 8.85 ± 1.49 and 10.00 ± 1.41 thrips/plant in the resistant, moderately resistant, susceptible and highly susceptible genotypes, respectively. The sugars, phenols,tannins, and amino acids in the plant tissues, and the leaf morphological characters are also analysed and correlations brought out.