To minimize travel to light traps sited at a considerable distance from headquarters, the authors have developed a battery of seven light traps, to keep nightly catohes separate and in good condition for a period of up to one week.The 100-watt clear, incandescent attractant lights are switched on in succession by a programmed multiple switch based on a seven-day, clock-driven thermograph drum. Seven cams are fitted at intervals equivalent to 24 hours on the drum surface, each of arc length to keep one of the seven roller lever actuator switches closed for the night hours of orie dav per week.