Seasonal Occurrence of the Sesame Capsule Borer, Antigastra catalaunalis (Duponchel) and Parasitism Rate of the Ecto-larval Parasitoid Bracon hebetor Say in Sesame Plants at Ismailia

Abstract

Field studies were conducted on the seasonal incidence of sesame capsule borer, Antigastra catalaunalis (Duponchel) (Lepidoptera: Pyralidae) and parasitism rate of its ecto-larval parasitoid Bracon hebetor Say (Hymenoptera: Braconidae) in two successive seasons of 2012 and 2013 at Ismailia Governorate. Results indicated that A. catalaunalis larvae appeared in mid-June (15 day after sowing) then increased gradually till the end of crop maturation (2 nd or 3 rd week of September). The highest percentage of infested branches, leaves, flowers and capsules was 75, 72.5, 62.5 and 47.5% respectively in the first season and 70, 70, 55 and 45%, respectively in the second season. The incidence of A. catalaunalis larvae was higher in leaves or shoots than in flowers or capsules. Ambient temperature had a positive and significant correlation with percentage of infestation by A. catalaunalis as well as number of larvae per infested branches and flowers in the first season while it had non-significant negative correlation in the second season. The mean relative humidity percentages showed non-significant negative relationship with percentages of infestation or pest incidence during the two seasons. Rate of parasitism by B. hebetor varied among plant parts in which A. catalaunalis larvae were fed on during the two seasons; being higher in the second season. Maximum parasitism percentages were 28.3, 32.5, 26.3 and 20 % in infested branches, leaves, flowers and capsules in the first season and increased to 38.7, 41.7, 35.8 and 21%, respectively in the second one.