A 100 years of biological control of sugarcane pests in India: review and perspective.

Insect pests constitute a major biotic stress in sugarcane in India as they attack the crop from the time of planting until almost harvest, inflicting yield and sugar losses. Biological control has always received a prominent position among the pest management tools, facilitated by the unique semi-perennial crop habitat and low pesticide usage. Biocontrol research of the early 1930s and 40s was characterized by surveys focusing on identification and studies on the basic biology of natural enemies. Conservation and re-distribution, and introduction and colonization of predominant parasitoids was practiced very early, and even in the recent past, with remarkable success. Mass multiplication and field evaluation that began in the early decades continue today, as is demonstrated by the use of the most exploited parasitoid <i>Trichogramma chilonis</i>. Several parasitoids and predators of borers and sucking pests were investigated systematically when the need arose. Among entomopathogens, granulosis viruses and fungi received considerable attention; a simple formulation of <i>Beauveria brongniartii</i> reached commercial production for the control of the white grub <i>Holotrichia serrata</i>. In recent years, isolates of <i>Bacillus thuringiensis</i> from sugarcane soil have been examined and a scarabaeid-specific <i>cry</i> gene has been identified. Preliminary studies of kairomonal principles from borers as attractants to the larval parasitoid <i>Cotesia flavipes</i> have been carried out. Organizational support to the cause of biological control includes coordinated research efforts from government agencies, production of biocontrol agents by commercial insectaries and promotion of technologies by the sugar industry. In this review, we chronicle the major research findings over the past eight decades, portray an overview of their significance and project the prospects and priorities for biological control research and promotion in the country.