Temperature-dependent development of Oenopia conglobata (Col.: Coccinellidae) fed on Aphis gossypii (Hem.: Aphididae)

Ladybeetles are known beneficial insects, with a long history in augmentative and classical biological control. The ladybeetle Oenopia conglobata (L.) is a natural enemy of many herbivores, particularly aphids. The temperature-dependent development of O. conglobata was studied at six constant temperatures (22.5, 25, 27.5, 30, 32.5 and 35 degrees C) to understand its development rate and environmental constraints better. Linear and nonlinear (Lactin) models were fitted to the data. In the thermal range from 22.5 to 32.5 degrees C, the rate of development increased for all stages; 35 degrees C was lethal for all stages and no eggs hatched. The Tb and K values for the biological cycle (egg-adult) were 8.84 degrees C and 263.15 DD, respectively. Depending on the model, t(min) values for the total development time of the coccinellid ranged from 8.45 to 8.82 degrees C. The nonlinear model of Lactin estimated the optimum and upper temperature thresholds for the total development time of the ladybeetle to be 33.2 and 35.0 degrees C, respectively. High R-2 values and low residual sum of squares values revealed a good fit to the experimental data for total development and different developmental stages of O. conglobata. The results may contribute to the improvement of practical methods for mass rearing of O. conglobata.