Thermal threshold and thermal requirement of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) under constant temperatures

The influence of temperatures (10-40°C) on the development and reproduction of Chrysoperla carnea was evaluated at constant temperatures. The study results indicated that the developmental periods of various life stages of C. carnea decreased with the increase in temperature. Males have shown shorter developmental periods compared to females. Fecundity is higher (190.59 eggs/female) at 25°C and decreased with the increase in temperature within the range of 92.35 to 26.01 eggs/female at 30°C and 35°C, respectively. Linear regression model was used to determine the lower developmental thresholds.  Egg, larval and pupal developmental thresholds were recorded at 9.6°C, 8.8°C and 8.75°C, respectively and 100, 200 and 125 DD are required for eggs, larvae and pupae, respectively. The present study can be used to predict the efficiency and utilization of C. carnea under field conditions.