Biocontrol of Chilo sacchariphagus (Lepidoptera: Cramidae) a key pest of sugarcane: Lessons from the past and future prospects

BIOCONTROL of sugarcane stemborers using Trichogramma releases is a common strategy used in numerous countries, and the efficacy of such releases has been proven in most cases. On Reunion Island, the key stemborer Chilo sacchariphagus and its egg parasitoid Trichogramma chilonis have been the subject of intensive research for 10 years. From the identification of the best candidate for biocontrol to mass production and experimental releases in sugarcane fields, improvement has been constantly made through the years, with successful results. In this paper, we report some of the important outcomes, problems encountered and questions that have arisen during the field experiments (Reunion) and laboratory rearing activities (Reunion and France). Behind promising results from an eco-friendly technology that is used worldwide, one of the current debates that remain is the cost of such biocontrol to the growers. Since 2008, a new research and development project has been conducted to optimise the technology of field releases as well as to increase the efficacy of mass production and storage at cold temperature. To deal with profitability and quality and establishing a new industrial process for Trichogramma production, a partnership has been formed with a French company, BIOTOP, which has extensive experience in biocontrol of the maize stemborer Ostrinia nubilalis in France. (Résumé d'auteur