Stress signals of water scavenger beetles Berosus frontifoveatus Kuwert, 1888 and Berosus spinosus Steven, 1808 (Coleoptera: Hydrophilidae)

Abstract
The study of acoustic signals from various representatives of insects, and in particular coleopterans, has a long history. In the Russian-language literature, systematic, faunistic and ecological studies on aquatic beetles, including those on the family Hydrophilidae, are widely known; however, studies on the bioacoustics of the coleopteran group are quite rare. The aim of our study was to study stress signals of two species of Hydrophilidae – Berosus frontifoveatus Kuwert, 1888 and Berosus spinosus Steven, 1808. The sounds of adults were recorded using a Behringer ECM8000 measuring condenser microphone. The sounds of B. spinosus males have a maximum frequency of occurrence in the range of 3729.31–4013.75 Hz, sounds of B. frontifoveatus is 4895.42–5842.76 Hz. The sounds of B. spinosus females have a maximum frequency of occurrence between 2585.98 and 2807.82 Hz. The sounds of B. frontifoveatus females have a maximum performance of the dominant frequency in the range of 2745.21–3476.23 Hz.