Emergence of Amphibious Insects from an Old Beaver Pond in the Upper Khoper Valley under Conditions of the Forest Steppe

This work presents the results of studies of the emergence of amphibiotic insects from the old beaver pond on the Yuzhnaya River of the Privolzhskaya Lesostep Nature Reserve in the Upper Khoper basin. The parameters of abundance, biomass, and frequency of occurrence are given for insects from 34 families and 8 orders; the timing of their emergence in different parts of the pond is indicated. The dominant and common species are identified: chironomids Paramerina cingulata (Walk.) and Cricotopus silvestris (F.), biting midges ( Bezzia bicolor (Mg.)), chaoborids Chaoborus flavicans (Mg.), and mayflies Cloeon inscriptum (Bgtss.). The intensity of the emergence of insects is 12.10 individuals/m 2 per day; the average daily transfer of biomass is 49.23 mg/m 2 per day. The analysis of the fatty acid composition and content of the main biogenic elements in adults of amphibiotic insects is carried out. The results of calculations of the energy and matter transfer, including biogenic elements (carbon, phosphorus, and nitrogen) and polyunsaturated fatty acids (PUFAs) during the emergence of insects from various orders (Ephemeroptera, Odonata, Trichoptera, and Diptera) into adjacent terrestrial ecosystems, are presented. The transfer of wet biomass from water to land is 7.385 g/m 2 per year and, in dry weight, 2.216 g/m 2 per year; transfer of the main nutrients is carbon, 1.21 g/m 2 per year; nitrogen, 0.25 g/m 2 per year; and phosphorus, 0.03 g/m 2 per year. PUFA transfer is 24.16 kg/km 2 per year.