Effects of Temperature on Development and Survival of Orthopygia glaucinalis (Lepidoptera: Pyralidae) Reared on Platycarya strobilacea

The larvae of Orthopygia glaucinalis (L.) (Lepidoptera: Pyralidae) are used to produce insect tea in Guizhou, China. We investigated the development and survival of O. glaucinalis reared on dried leaves of Platycarya strobilacea under laboratory conditions at 19, 22, 25, 28, 31, 34, and 37°C. The duration of development from egg deposition to adult emergence decreased significantly with increasing temperature from 19 to 31°C, whereas the duration of egg and overall development significantly increased at 34°C. Based on the extreme-value distribution function, the optimal temperature for survival of overall development was 24.89°C, and the larval stage was most susceptible to temperature extremes. The common linear model and the Ikemoto and Takai linear model were used to determine the relationship between temperature and the developmental rate, and estimated the low-temperature threshold (11.44 and 11.62°C, respectively) and the threshold constant (1220.70 and 1203.58 degree-days, respectively) of O. glaucinalis. Nonlinear models were used to assess in fitting the experiment data and to estimate the high temperature thresholds (34.00 to 39.08°C) and optimal temperatures (31.61 to 33.45°C). An intrinsic optimal temperature of 24.18°C was estimated for overall development using the Sharpe-Schoolfield-Ikemoto (SSI) model. Model-averaged parameter estimates and the unconditional standard error were also estimated for the temperature thresholds. Based on the biological parameters and model selection, we concluded that common linear, Lactin-1, and SSI models performed better for predicting the temperature-dependent development of O. glaucinalis. Our findings enable breeders to optimize the developmental rate of O. glaucinalis and improve the yield of insect tea.