Models to describe the thermal development rates of Cycloneda sanguinea L. (Coleoptera: Coccinelidae)

Abstract

Precise estimates of the lower (T_min) and higher (T_max) thermal thresholds as well as the temperature range that provides optimum performance (T_opt) enable to obtain the desired number of individuals in conservation systems, rearing and release of natural enemies. In this study, the relationship between the development rates of Cycloneda sanguinea L. (Coleoptera: Coccinelidae) and temperature was described using non-linear models developed by Analytis, Brière, Lactin, Lamb, Logan and Sharpe & DeMichele. There were differences between the models, considering the estimates of the parameters T_min, T_{max ,} and T_opt. All of the tested models were able to describe non-linear responses involving the development rates of C. sanguinea at constant temperatures. Lactin and Lamb gave the highest z weight for egg, while Analytis, Sharpe & DeMichele and Brière gave the highest values for larvae and pupae. The more realistic T_opt estimated by the models varied from 29° to 31°C for egg, 27-28 °C for larvae and 28-29 °C for pupae. The Logan, Lactin and Analytis models estimated the T_max for egg, larvae and pupae to be approximately 34 °C, while the T_min estimated by the Analytis model was 16 °C for larvae and pupae. The information generated by our research will contribute towards improving the rearing and release of C. sanguinea in biological control programs, accurately controlling the rate of development in laboratory conditions or even scheduling the most favourable this species' release.

Keywords: Ladybug; Non-linear regression; Optimum performance temperature; Thermal threshold.