Biology and seasonal incidence of leafhopper, Amrasca biguttula biguttula (Ishida) (Hemitpera: Cicadellidae) on okra

Biology of Amrasca biguttula biguttula (Ishida) and its seasonal incidence in relation to biotic and abiotic factors on okra was studied at College of Agriculture, Shimoga, India. The developmental periods of egg, first, second, third, fourth and fifth instar were fourth and fifth instar were 6.42 ± 0.37, 1.49 ± 0.33, 1.19 ± 0.22, 1.16 ± 0.15, 1.60 ± 0.39 and 1.97 ± 0.29 days, respectively. The total nymphal period was 7.41 ± 0.48 days. The pre-oviposition, oviposition and post-oviposition periods were found to be 3.52 ± 0.34, 16.54 ± 0.37 and 3.85 ± 0.24 days, respectively. The fecundity varied from 14.00 to 20.00 with an average of 16.60 ± 1.98 eggs per female. The average longevity of male and female adults was 22.85 ± 1.87 and 26.66 ± 1.92 days, respectively. The highest incidence (16.44 leafhoppers/plant) was observed during March second fortnight, while the lowest (0.25 leafhoppers/plant) was observed during December second fortnight. The leafhopper population had a significant positive correlation with the maximum temperature and a significant negative correlation with rainfall. But relative humidity had no significant effect.