Vol. 11, Special Issue 11 (2022)

Leaf and fruit scarring beetle Basilepta subcostata (Jacoby) is a major pest of concern in case of banana. To address the issue a field experiment was carried out at the farmer’s field of Samaguri, Nagaon during 2019-20 and 2020-21. Total six treatments were imposed viz., - T₁: three spray of neem product (Azadiractin, 1500 ppm) @ 5 ml/lit; T₂: three-time filling of leaf axil with Beauveria bassiana (AAU Culture @ 10⁸ spore), 5 ml /lit; T₃: three sprays of Beauveria bassiana (AAU Culture) @ 108 spore) 5 ml /lit; T₄: bunch covering with plastic bags (17 GSM polypropylene bag); T₅: sprays Cholropyrifos 20EC @ 2.5 ml/lit; and T₆: untreated control. The results revealed that the efficacy of Beauveria bassiana (filling of leaf axil with B. bassiana and spray of B. bassiana), Neem insecticides (Azadirachtin 1500 ppm), bunch covering with plastic bags and spray of chemical insecticides (chlorpyrifos 20 EC) were very much effective for reduction of the leaf scarring beetle per plant after third spray in comparison to untreated control plot. However, amongst the different treatments, bunch covering with plastic bag was the best treatment in suppressing the population of beetles i.e., 8.42 and 8.63 per plant followed by 9.42 and 9.72 numbers of beetle per plant in chlorpyrifos 20 EC @ 2.5 ml/lit treated plot during 2019-20 and 2020-21, respectively. Moreover, in case of entomopathogenic fungi, the treatments of filling of leaf axil with B. bassiana (AAU culture) @ 5ml/lit, spray of B. bassiana (AAU culture) @ 5 ml/lit and Neem product (Azadirachtin 1500) @ 5 ml/lit influenced insect population with 12.25, 12.67 and 13.42 beetles per plant during 2019-20; whereas 10.73, 11.60 and 11.37 beetles per plant recorded during 2020-21.