Compar-isons were made of the attractiveness of 100-watt u. v. lamps, between 3000 and 3800 A, and ordinary 10-, 25-, 50-, and 100-watt white lamps. The tests were conducted with lights separated by 100 feet and with lights separated by only 3 feet. All insects were identified at least to orders and families. In general they responded more strongly to the u.-v. regardless of position. The Miridae and Chrysopidae seemed to be exceptions. The very strong response of certain groups such as the Drosophilidae and Microlepidoptera are illuminating and have not previously been recognized.