Determining the efficacy of push-pull for management of Eldana saccharina (Walker (Lepidoptera: Pyralidae) in sugarcane through on-farm field trials in KwaZulu-Natal.

Abstract

An area-wide integrated pest management (AW-IPM) programme was developed to improve management of Eldana saccharina Walker (Lepidoptera: Pyralidae), a major pest of South African sugarcane. Push-pull technology is an important component of this AW-IPM approach. The sugarcane push-pull programme uses plants which are both repellent (Melinis minutiflora P. Beauv. (Cyperales: Poaceae)) and attractive (Cyperus dives Delile and Cyperus papyrus L. (both Cyperales: Cyperaceae) to E. saccharina. Previous research demonstrated the efficacy of push-pull in the Midlands North region of KwaZulu-Natal (KZN), South Africa. To date, little research has been conducted in coastal sugarcane growing areas. The aim of this study was to assess the feasibility of using push-pull for management of E. saccharina in coastal KZN, using large-scale on-farm field trials conducted on five model farms. On each farm, wetland habitats were rehabilitated with pull plants (C. dives and C. papyrus) and fields were intercropped with the repellent grass M. minutiflora. Eldana saccharina damage and infestation levels were recorded to assess the efficacy of push-pull, using a multiple before-after-control-impact (mBACI) design. Push-pull treatment sites showed a significant reduction in mean percentage stalk damage and E. saccharina abundance relative to control sites. Furthermore, stemborer surveys in wetland habitats revealed higher numbers of E. saccharina within Cyperus spp. stands. Pull plants were therefore effective at attracting E. saccharina away from sugarcane. The success of the push-pull trials in this study indicates that it is a useful tool for managing E. saccharina populations in coastal sugarcane, especially in conjunction with other management practices.