Abstract: 【Aim】 To clarify the degradation regulation of chlortetracycline residue by the black soldier fly, Hermetia illucens. 【Methods】 The eggs of H. illucens collected on the same day were cultured to the 3-day-old larvae, then transferred to the mixed diets of wheat bran and chlortetracycline residue in different mass ratios (wheat bran∶chlortetracycline residue=1∶0, 1∶1, 2∶1, 5∶1, 10∶1 and 20∶1), and the body length and body weight of different day-old larvae were measured, meanwhile, the degradation rate of chlortetracycline by different day-old larvae were calculated based on the chlortetracycline contents in H. illucens larvae and diet residues.【Results】 The content of chlortetracycline residue in the mixed diets exhibited significant effects on the biological characteristics such as body length and body weight of H. illucens larvae, and the degradation rate of chlortetracycline by different day-old larvae of H. illucens. The body length and body weight of H. illucens larvae reared with the mixed diets of wheat bran and chlortetracycline residue in different mass ratios were increased with the day-old age of larvae until 11-day-old, and then decreased at the 13-day-old larval stage. The body length and body weight of H. illucens larvae reared with the mixed diets of wheat bran and chlortetracycline residue in the mass ratios of 5∶1, 10∶1 and 20∶1 were bigger than those of the control group cultured with the pure wheat bran. The initial content of chlortetracycline had a significant effect on the degradation rate of chlortetracycline by different day-old larvae of H. illucens through the comparison of degradation rates of chlortetracycline by different day-old larvae of H. illucens reared with the mixed diets of wheat bran and chlortetracycline residue in different mass ratios. The degradation rates of chlortetracycline by the 7-, 9-, 11- and 13-day-old larvae reared with the mixed diets of wheat bran and chlortetracycline residue in the mass ratio of 5∶1 were 39.21%, 68.94%, 66.53% and 68.26%, respectively, significantly higher than those by the larvae reared with the mixed diets of wheat bran and chlortetracycline residue in the mass ratios of 10∶1 and 20∶1.【Conclusion】 H. illucens is able to reduce the content of chlortetracycline residue, and the initial content of chlortetracycline in diets has a significant effect on the biological characteristics of H. illucens and degradation rate of chlortetracycline.

Key words: Hermetia illucens, chlortetracycline residue, degradation rate, growth and development, reduction