Shubhasree Dash, Rajasekhara Rao Korada, Shubhalaxmi Roy and Bijoy Kumar Mishra
Abstract
An experiment was conducted to assess the influence of different temperatures on the growth and development of fall armyworms under laboratory conditions at the Institute of Agriculture Sciences, SOADU, between the year 2022-2023. This study examined the biological stages of fall armyworm under four distinct constant temperatures: 20 ðC, 25ðC, 30 ðC, and 35 ðC, all maintained at a constant relative humidity of 65 ñ 5% within a BOD incubator. Observations revealed that the duration of the life stages decreased as the temperature increased from 20 ðC to 35 ðC. The egg period reduced from 6.08ñ0.06 days at 20ðC to 2.36ñ0.05 days at 30 ðC, while the larval period similarly shortened from 25.14ñ0.06 days at 20ðC to 9.54ñ0.06 days at 35 ðC. The development duration of the pupa also significantly decreased from 17.2ñ0.07 days at 20 ðC to 6.50ñ0.07 days at 35 ðC. Notably, the male pupae took a longer time to develop compared to female pupae. The adult lifespan of both males and females decreased with increasing temperatures from 20 ðC to 35 ðC. The study revealed that females generally lived longer than males. Egg hatchability was highest at 25 ðC 94.20ñ0.5) and lowest at 35 ðC (48.40ñ0.67). The survival percentage of larvae was highest at 30 ðC (95%) followed by 89% at 25 ðC. The findings of the study indicated that temperature ranges between 25 ðC and 30 ðC were favourable for the growth and development of fall armyworms, while extremes of 20 ðC and 35 ðC were not suitable for proper development.