MODIFICATION OF HELICOVERPA ARMIGERA ONTOGENESIS UNDER CLIMATE CHANGE AS A BASIS FOR AN ADAPTIVE PRECISION PROTECTION SYSTEM IN WESTERN POLISSIA

Abstract

Under conditions of global climate change, a profound restructuring of agroecosystem organization is taking place, accompanied by shifts in species ranges and alterations in the biology of many economically important insect pests. Particularly sensitive to transformations in the thermal regime are highly adaptable polyphagous species capable of rapidly modifying their developmental phenology and establishing stable populations in novel agroclimatic zones. In this context, the study of naturalization processes of southern phytophagous insects in more northern regions of Ukraine, as well as the development of scientifically substantiated approaches to regulating their population density, is of high relevance. This article presents the results of a comprehensive investigation into the adaptation of the cotton bollworm (Helicoverpa armigera Hbn.) and substantiates an effective strategy for regulating its population under conditions of agroclimatic transformation in Western Polissia, particularly within Rivne and Volyn oblasts. A persistent trend toward an increase in mean annual air temperature of +0.67° C per decade has been identified, accompanied by a substantial rise in the accumulated sums of effective temperatures exceeding 1500° C. Under such conditions, H. armigera transitions to a stable bivoltine developmental pattern with the formation of a facultative third generation. The combination of elevated thermal background and relatively high air humidity (50–60%) creates favorable conditions for the survival of preimaginal stages and ensures successful overwintering of the autochthonous pest population. A cumulative nature of phytophagous damage has been documented, whereby direct yield losses in maize and sunflower are exacerbated by an increased risk of product contamination with mycotoxins (fumonisins and zearalenone) resulting from the epiphytotic development of Fusarium spp. at sites of insect injury. Based on the research findings, the necessity of abandoning the traditional calendar-based plant protection approach is substantiated, and an adaptive integrated pest management system is proposed. This system relies on precision instrumental monitoring, biological population regulation using Trichogramma evanescens, and an anti-resistance chemical strategy centred on the use of anthranilamides and chitin synthesis inhibitors, combined with agronomic measures aimed at the destruction of overwintering pupae.