Natural parasitism of Telenomus busseolae (Hym.: Scelionidae) an egg parasitoid of sugarcane stem borers, Sesamia spp. (Lep.: Noctuidae), on sugarcane commercial varieties in Khuzestan

The sugarcane stem borers, Sesamia cretica Led. and S. nonagrioides Lef. are the most important pests of sugarcane in Iran. The egg parasitoid wasp, Telenomus busseolae Gahan is the most important natural enemy of Sesamia spp. in Khuzestan province that play an important role in regulating populations of sugarcane stem borers. A field experiment was conducted to evaluate the performance of T. busseolae on sugarcane commercial varieties in Khuzestan province (southwest of Iran). This study was conducted in a split plot design on 4 sugarcane commercial varieties (i.e. CP69-1062, CP48-103, CP57-614 and SP70-1143) with 5 fields per variety in Khuzestan in 2007. The sampling of egg masses were carried out within the tillering stage of sugarcane (5-15 June) and the final stage of sugarcane growing (10-20 October). Our results indicated that both growth stage and variety of sugarcane had a significant effect on the egg batch density, discovery efficiency and percent parasitism. The interaction between growth stage and variety on percent parasitism and discovery efficiency were statistically different (P<0.01). The effects of growth stage, variety and interaction between them on parasitism efficiency, adult emergence and F1 progeny sex ratio were not statistically significant. The highest egg batch density, discovery efficiency and percent parasitism was observed on the CP48-103 variety. Based on our results, T. busseolae shows considerable parasitism on this variety.