Resistance mechanisms of South African sugarcane to the stalk borer Eldana saccharina (Lepidoptera: Pyralidae): a review.

wax, gene expression Despite plant resistance constituting one of the major defences of South African sugarcane against the stalk borer, Eldana saccharina Walker (Lepidoptera: Pyralidae) (Leslie and Keeping, 1996; Keeping, 1999; Keeping and Govender, 2002), little has been published regarding the mechanisms upon which this resistance is based. This paper reviews published and unpublished information on this subject, in an attempt to synthesise our understanding of the major resistance mechanisms against E. saccharina. The first line of plant defence – ovipositional antixenosis – is apparently unimportant in the E. saccharina-sugarcane interaction. Several studies (Nuss and Atkinson, 1983; Mabulu and Keeping, 1999; Anon, 2003) using potted sugarcane of resistant and susceptible varieties placed in cages in a glasshouse, yielded no evidence that mated female moths preferred certain varieties over others for oviposition. Therefore, it appears that resistance is largely, if not entirely, based on the reaction of the larval stages to physico-chemical factors both on the outside and inside of stalks. Leslie (1993) found that penetration of stalks by neonate larvae in the field over the first four