Abstract: 【Aim】 To explore the effects of temperature on development and humoral immune defense of Tenebrio molitor larvae. 【Methods】 We investigated the larval duration, pupal weight, pupation rate of T. molitor reared at different temperatures (18, 22, 26 and 30℃). After immunization treatment (1 μL of physiological saline containing 1×104 cells of Escherichia coli was injected into the back of abdomen of each larva) and non-immunization treatment (physiological saline injected), the bacteriolytic and antibacterial activities in the hemolymph of T. molitor larvae reared at different temperatures were investigated via inhibition zone assay, and the phenoloxidase activity in the hemolymph was investigated by spectrophotometry. 【Results】 The developmental duration of T. molitor larvae decreased as temperature increased. There was a significant negative correlation between larval duration and temperature (P<0.0001), while the pupal weight (P=0.067) and the pupation rate (P=0.869) did not significantly differ at different rearing temperatures. The phenoloxidase, lysozyme and antibacterial activities in the hemolymph of immunized T. molitor larvae decreased with the increase of temperature. At different temperatures both phenoloxidase and antibacterial activities were extremely significantly different (P<0.0001), while the lysozyme activity was significantly different (P=0.013). 【Conclusion】 The results show that temperature has significant effects on the growth and development and the immune defense of T. molitor larvae. At lower rearing temperature the larval duration lengthens and the humoral immune defense significantly increases.

Key words: Tenebrio molitor, temperature, growth and development, humoral immune, phenoloxidase, lysozyme