Population dynamics of paddy stem borers in relation to biotic and abiotic factors.

摘要

Population dynamics of paddy borers in Haryana during kharif 2004 revealed that the population of borers fluctuated in different periods during the season. The maximum number of eggs and pupae were recorded in the first week of October, while the maximum larvae were recorded in the third week of October indicating that population of borers (yellow stem borer and pink stem borer) builds up late in season. Among the borers, yellow stem borer predominated throughout the season, while pink stem borer was dominating towards the maturity of the crop (2.26-23.01%). Though the egg parasitism was good (62.0%), larval and pupal parasitism was almost nil. Telenomous dignus was dominating egg parasitoid. The maximum temperature, minimum temperature and evening relative humidity exhibited a negative relationship with total number of larvae. The relationship between mortality of larvae and maximum temperature was positive while it was negative with morning relative humidity.