Utility of Trichogramma for biocontrol of sugarcane borers

Abstract

Sugarcane tissue borers are an important constraint to sugarcane productivity and juice quality. There are several species of borers occurring in varying intensities across the country. The mass production and release of Trichogramma species for biocontrol of sugarcane borers in India have been recommended by researchers over several decades starting from early work in Mandya in the 1930s. The focus of R&D during the four decades from the 1960s includes mass production methods and packaging/delivery systems, field release rates and release frequencies, field release points and their importance, improvements in climatic stress adaptation, integration with insecticide use, effect of sugarcane varieties on release impact and integration with cultural practices. Nevertheless, the critical progress in multiple release impact validation during the 1970s and 1980s in South India represents a major milestone, leading to the establishment of large number of mass production units in both public and private sectors. The more recent and ongoing research, especially on developing insecticide-tolerant Trichogramma strains, comparing the impact of different release regimes and linking Trichogramma releases to pheromone trap use, is summarised. The scope for future research towards enhancing Trichogramma impact potential, especially through monitoring borer abundance/peaks for timing of releases; targeting the major borers in different agro-climatic regions; selectively deploying locally adapted strains/populations; timing and frequency of releases for maximum control; improving storage, packing and delivery systems; and local refinement of Trichogramma release under individual factory R&D, besides undertaking on-farm validation of the economic benefits to the farmer and the factory, is discussed.