Impact of Thermal Stress on Biological Parameters of Chrysoperla zastrowi sillemi (Esben Petersen) under Laboratory Conditions

Abstract

Aphid lions (Chrysoperla zastrowi sillemi, Esben-Petersen) are important predators in integrated pest management for field crops and vegetables (Neuroptera: Chrysopidae). It is found in almost every environment on Earth, except temperate ones. One of the most significant environmental variables influencing an insect species' growth rate is temperature. Five consistent temperatures were observed: 20±1°C, 25±1°C, 30±1°C, 35±1°C, and 40±1°C. The impact of temperature on biological parameters and developmental phases of Aphid lions feeding on rice moth eggs was noted. The development time of C. zastrowi sillemi was found to be 47.26 days at 20°C and 22.18 days at 40°C. The lifespan of adult males and females was more than twice as long at the lower temperature range as it was at the higher one. The temperature of 25°C produced the greatest duration of oviposition (55.12 days), the highest percentage of pupils (91.43%) and adults’ emergence (90.25%), the maximum fecundity (903.33 eggs/female), and the maximum degree of hatchability (90.84%) of eggs, suggesting that this temperature regime was more suited for the C. zastrowi sillemi that originated in Delhi. The results demonstrate significant variations in the developmental cycle of the immature stages at five distinct temperatures, with a negative relation between temperature increase and developmental duration.