BIOLOGICAL ACTIVITY OF ENTOMOPATHOGENIC FUNGI STRAINS AGAINST COLORADO POTATO BEETLE LARVAE

Abstract

The Colorado potato beetle is a primary threat to potato fields, causing significant damage, particularly through the activities of young beetles and larvae within the first 3-4 years of their lifecycle, which can result in up to 90% leaf surface damage. Temperature plays a critical role in its development, with growth slowing below 14°C and mass mortality occurring above 38°C. The period between July and August poses the greatest risk to potatoes [1,5].

Presently, chemical insecticides dominate the landscape for Colorado potato beetle control. However, their widespread use raises significant environmental concerns. Therefore, the search for alternative, non-chemical, environmentally friendly methods of control is imperative. Among these alternatives is the microbiological approach [2,4]. Consequently, we conducted experiments to assess the biological activity of ten strains of collected entomopathogenic fungi against Colorado potato beetle larvae. The primary objective of this study is to stabilize these fungal strains and enhance their biological activity, aiming to provide a more effective solution against harmful insects.

The larvae of the Colorado potato beetle utilized in this study were gathered from potato fields in the Karasai district of the Almaty region. Ten strains, based on Beauveria bassiana, Beauveria pseudobassiana, and Isaria farinosa, were selected from the entomopathogenic fungi collection at the institute's biotechnology laboratory to identify strains virulent to the Colorado beetle.