Abstract: 【Aim】 To explore the effects of different LED light sources in scotophase at variable temperatures on the rhythmicity in pupation, eclosion, mating, oviposition and egg hatching activities of Calospilos suspecta. 【Methods】 Under laboratory conditions, the pupation, eclosion, mating, oviposition and egg hatching of C. suspecta were observed every hour for 5 d in the control group (under the photoperiod of 14L∶10D) and two treatment groups subjected to 10-h red LED light and 10-h yellow LED light irradiation, respectively, in scotophase (represented by 14L∶10R and 14L∶10Y, respectively). The rates of pupation, eclosion, mating, oviposition and egg hatching were calculated, and the differences in these parameters in photophase or scotophase among experimental groups, and between photophase and scotophase within each group were compared. 【Results】 The pupation of C. suspecta didn’t show obvious circadian pattern under red or yellow LED light irradiation. Pupation in 14L∶10D and 14L∶10Y groups mainly occurred in photophase, and the peak of pupation occurred at 7:00-8:00 and 18:00-19:00, respectively. Pupation in 14L∶10R group mainly occurred in scotophase, and the peak of pupation occurred at 22:00-23:00. However, different LED light treatments in scotophase didn’t significantly affect the pupation rates per hour. The eclosion didn’t show obvious circadian pattern under red or yellow LED light irradiation. Eclosion of female and male adults in 14L∶10D and 14L∶10R groups mainly occurred in photophase, while that in 14L∶10Y group mainly occurred in scotophase. The peak of eclosion in 14L∶10D and 14L∶10R groups occurred on the 1st-2nd hour of photophase. The eclosion rates of female adults per hour in scotophase were significantly affected by LED light treatments. In 14L∶10D group, the eclosion rates of female adults per hour in photophase were significantly higher than those in scotophase. However, two different LED light treatments in scotophase didn’t significantly affect the eclosion rates of male adult per hour. The mating showed obvious circadian pattern. Mating in all groups mainly occurred in scotophase, and the peak of mating occurred at 1-2 h before scotophase (4:00-6:00). In 14L∶10D and 14L∶10Y groups, the mating rates per hour in scotophase were higher than those in photophase. The oviposition also showed obvious circadian pattern. The peak of oviposition in 14L∶10D and 14L∶10R groups and the sub-peak of oviposition in 14L∶10Y group occurred at 20:00-21:00 in the scotophase, while the peak of oviposition in 14L∶10Y group occurred at 16:00-17:00 in photophase. The oviposition rates per hour were not significantly affected by different LED light treatments in scotophase. The egg hatching showed obvious circadian pattern. The peak of egg hatching in various groups occurred on the 1st hour of photophase. Different LED light treatments had no significant effects on the egg hatching rates per hour. 【Conclusion】 Under red and yellow LED light treatments, the pupation and eclosion of C. suspecta didn’t show obvious circadian pattern, while the mating, oviposition and egg hatching of C. suspecta showed obvious circadian pattern. LED light irradiation in scotophase influences some life activities of C. suspecta and these effects vary with LED light colors.

Key words: Calospilos suspecta, LED light irradiation, life activities, circadian pattern, photophase, scotophase