Population Dynamics of Shoot and Fruit Borer Earias Vitella on Okra

Abstract

Field experiment to evaluate the population dynamics of okra shoot and fruit borer Earias vitella F., was conducted at the Research Farm, Tirhut College of Agriculture, Dholi, Muzaffarpur, Bihar during kharif 2018 and 2019. The observations revealed that its shoot infestation initiated from 29th standard week (SW) (3.84%) and reached its peak (10.09%) during 31st SW. The fruit damage was first noticed during 31st SW (4.91%), continued till 41st SW (6.44%) reaching peak (29.30%) at 34th SW. The larval count on fruit was of a maximum (7.13 larva/ 25 fruit) during 31st SW. The maximum and minimum temperature and relative humidity at 7 hr were found positively correlated with fruit damage (r = 0.512, 0.286 and 0.217, respectively). The larval counts exhibited a positive and significant relationship with maximum temperature (r = 0.549) while that of minimum temperature (r = 0.327) and relative humidity at 7 hr (r = 0.211) were positive and nonsignificant. The weather factors collectively infulenced 64.10, 87.10 and 86.90% of shoot and fruit damage and larval counts, respectively.