Locomotion Activity Meter for Quality Assessment of Mass-Reared Sterile Male Moths (Lepidoptera)

Irradiation is used to provide sterile insects from mass-rearing facilities, but irradiation can degrade insect quality. A system is described that uses repeatable pheromone stimuli to activate male moths housed with clean airflow in a commercially available insect activity meter, for potential use in quality assessment of mass-reared moths in sterile insect programs. We tested sexually mature wild and sterile light brown apple moth (LBAM), Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), males at the commencement of scotophase in a simple assay for increased mate-seeking activity after a 2 s stimulus with a 4-component synthetic pheromone source for 2 s, after a 5 s baseline of activity. Male activity at the upwind end of the glass tube was assessed by infrared beam. Next, we tested if a temperature shock at 30 °C in the pupal stage for various durations (0, 1, 2 or 4 h) would have an effect on male moth response to the sex pheromone. The results indicated similar baseline activity in clean airflow, but a significantly greater response after pheromone stimulation from non-irradiated males, compared with irradiated males. Responses from irradiated males averaged 78% of the control response (n = 320). The temperature shock did not appear to change the response of the non-irradiated moths (n = 64), but there was a slight decline in response by irradiated moths at the 2 and 4 h temperature shock durations. The system could be readily modified to be suitable for factory scale quality assurance.