Abstract: [Objective] The present paper aimed to study effects of elevated CO₂ concentration on the growth and development, nutrient utilization and in vivo detoxifying enzymes and protective enzymes of the serious forest defoliator, Lymantria dispar (Lepidoptera: Lymantridae). [Method] The different CO₂ concentrations (397, 550 and 750 μL·L^-1) were applied in the closed CO₂ artificial climate chamber, and the effects on growth and development of L. dispar were measured, and the effects on activities of detoxification enzymes and protective enzymes of L. dispar were determined by spectrophotometry. [Result] The elevated CO₂ concentration was able to prolong the egg hatching period of L. dispar, increased fecundity and hatching rate. At the same time, the elevated CO₂ concentration significantly prolonged the total larval developmental period, however, it had no significant effects on pupae and adult duration. Increased CO₂ concentration decreased the relative feeding rate and the approximate digestibility, but increased the food utilization rate and the conversion rate of digested food by L. dispar. The activities of superoxide dismutase (SOD) and catalase (CAT) in L. dispar larval body were significantly induced by 750 μL·L^-1 of CO₂ concentration, and increased by 32.05% and 13.47% compared with that at 397 μL·L^-1 CO₂ concentration, respectively; With the increase of CO₂ concentration, the activities of cytochrome P450 increased by 78.79% and 93.50% under 550 μL·L^-1 and 750 μL·L^-1 CO₂, respectively, compared with that at 397 μL·L^-1 CO₂. The GST activities were the highest under 550 μL·L^-1 CO₂ concentration, which was 71.03% and 50.00% higher than those in 397 μL·L^-1 and 750 μL·L^-1 treatment groups, respectively. [Conclusion] The elevated CO₂ concentration can affect the growth and physiological metabolism of the L. dispar larvae. At the same time, L. dispar can resist the high concentration of CO₂ through changing the developmental duration, increasing the food utilization and transformation, and changing the activities of detoxifying enzymes or/and protective enzymes to achieve the purpose of maintaining life.

Key words: Lymantria dispar, carbon dioxide concentration, growth and development, nutritional utilization, climate change, forest inscet