Abstract
The seasonal prevalence of moth flies breeding in a rural area of Yokohama was surveyed during the period from June to October in 1967 and all the year in 1968. Collection of the adult moth flies was made by black-light traps (Nozawa type) in two pigpens and a henhouse. Among the four species collected, T. albipunctatus and P. alternata were most common in this area. T. albipunctatus was collected successively during the period from May to December and it was most abundant in August in 1968 and September in 1967. Also P. alternata was common throughout the year of 1968 and three peaks in prevalence were seen in three seasons, May, June to July, and September to October; the highest among them was observed during the period from June to July.
