Trichogramma Chilonis and Bacillus thuringiensis for Sustainable Management of Sugarcane Top Borer (Scirpophaga Excerptalis) in Mardan

Abstract

The sugarcane top borer (Scirpophaga excerptalis) is a major pest of sugarcane in Pakistan, causing substantial yield losses and reducing farmer incomes. This study evaluated integrated pest management options for top borer under field conditions at the Sugar Crops Research Institute, Mardan, Khyber Pakhtunkhwa. Five treatments were compared: release of the egg parasitoid Trichogramma chilonis (50,000 adults/ha), application of Bacillus thuringiensis (Bt, 1.5 kg/ha), integrated treatment (T. chilonis + Bt), granular carbofuran (2.5 kg/ha, chemical standard), and an untreated control. The experiment used a randomized complete block design with four replications. Data were recorded on dead heart incidence, larval population, bored internodes, cane yield, sucrose content, and benefit cost ratio. The integrated treatment reduced dead heart incidence to 4.2% at 120 days, compared to 3.8% for carbofuran and 14.6% for the control (difference not statistically significant). Larval reduction reached 76% in the integrated treatment versus 81% in carbofuran. Cane yield was 68.2 t/ha for the integrated treatment (not significantly different from carbofuran at 69.5 t/ha) and 47.3 t/ha for the control. Sucrose content was 18.4% in the integrated treatment, comparable to carbofuran (18.1%). The benefit cost ratio was higher for the integrated treatment (3.9) than for carbofuran (2.8) due to lower input costs. The integrated treatment also preserved natural enemy populations, whereas carbofuran reduced them by 70%. The main finding is that integrating T. chilonis with Bt suppresses top borer damage almost as effectively as carbofuran while providing a safer, more economical, and ecologically sustainable IPM profile. This bio intensive package is recommended for smallholder sugarcane farmers in Mardan and similar regions.