IX - The influence of moonlight on the activity of certain nocturnal insects, particularly of the familyNoctuidae, as indicated by a light trap

Abstract

For many years amateur entomologists have considered that on nights of full moon it is of little use going out to catch specimens, as insects will be few in number. This belief applies to all methods of collecting, including bait (sugaring) and light, and is supposed to apply particularly to the Lepidoptera. Scattered through the literature on Agricultural Entomology one finds occasionally references to the use of light traps for the destruction of pests, and statements, usually from the tropics, that the catches were less at times of full moon ; but so far as I am aware no proper statistical study of the question has ever been made. One of the most striking series of figures is that produced by Pagden (1932) by trapping with a light trap the two Pyralid mothsDiatraea auriciliaandSchoenobius incertelluswhich are pests of rice in Malaya. He found, between 18 January and 29 June, 1931, six periods of maximum catch in both sexes of both species corresponding more or less to the no moon periods, and six periods of minimum catch corresponding even more definitely to the full moons. Scarcely any insects were captured at the time of full moon.