Seasonal Distribution, Sex Ratios, and Mating of Female Noctuid1 Moths in Blacklight Trapping Studies3

Abstract

Moths of the cabbage looper, Trichoplusia ni (Hubner) ; the corn earworm, Heliothis zea (Boddie) ; the armyworm, Pseudaletia unipuncta (Haworth) ; the yellowstriped armyworm, Prodenia ornithogalli Guenee, and the alfalfa looper, Autographa californica (Speyer), were collected from traps equipped with blacklight lamps in Home Gardens, and Riverside, California, in 1964–65 and studied to determine possible correlations between seasonal abundance, mating of females, sex ratios of the collections, and seasonal temperature. The abundance of the species varied between the 2 areas, both in total yearly catch and in the size of catches within a given trapping period. Mating appeared to be related more to the total density than to sex ratios during a trapping period. The yearly mating of each species was quite similar in the 2 areas, and the time of night at which the moths were trapped appeared to have little effect on the number of matings per female. Populations were generally higher during the summer months.