Flight Activity of the Sexes of Crambid Moths as Indicated by Light-Trap Catches

Abstract

Light trap collections of Crambus trisectus Walker; the bluegrass webworm, C. teterrellus (Zincken); C. mutabilis Clemens; the corn root webworm, C. caliginosellus Clemens; C. hortuellus Hubner; and the vagabond cram-bus. C. vulgivagellus Clemens, were made during the summers of 1963 and 1964 to determine flight activity for each species and for males and females of each species. A series of dusk-to-dawn collections of cram bid moths made at light traps showed a sex difference in time of peak flight activity. Females were found to be most responsive in the premidinight period and males in the post midnight period. Maximum flight activity of female moths came within 1½ to 2 hours after sunset. Following the hours of first abundance in the evening, the catches of female moths declined but increased slightly between 1 and 4 AM. The post midnight flight of males was larger and more prolonged than the female flight earlier in the evening. Flight activity of males and females was similar for all species.