The composition and functional structure of the intestinal microflora of three wireworm species (Agriotes obscurus (L.), Selatosomus aeneus (L.), and Ampedus pomorum (Herbst)) with different dietary regimes were studied. The total abundance of the microorganisms was evaluated by fluorescent microscopy, the group composition was assessed by inoculation on a solid glucose-peptone-yeast medium, and the functional diversity was estimated by multisubstrate testing. It was noted that, in the intestine of the larvae, the total number of microorganisms was lower by 1–2 orders of magnitude than in the soil and decaying wood. It was found that the composition of the intestinal microbial communities of wireworms was radically different from that of the substrate: the Bray-Curtis coefficient did not exceed 0.25. It was found that native forms accounted for more than half of the total number of saprotrophic bacteria: in the larvae, Gram-positive cocci, enterobacteria, Vibrionaceae, Acinetobacter, and some genera of coryneform bacteria, which were absent in the soil and wood, prevailed. The micromycetes were either absent (Agriotes) or were found in insignificant quantities (Selatosomus, Ampedus). In Selatosomus, apart from the intestinal forms, representatives of Mezorhizobium, Nocardioides, and Erwinia, occurring on plant substrates, were observed.

The effects of Elateridae larvae (wireworms) on the structure, functional diversity, and tolerance of the soil microbial population in steppe ecosystems have been investigated. The trophic and locomotor activity of wireworms leads to an appreciable increase in bacterial abundance and suppression of fungal activity. The fungal hyphae in the presence of wireworms are significantly damaged, which can be related to the feeding activity of Elateridae. The increase of bacterial abundance on the background of exclusion of the fungal component shifts the microbial succession to the acceleration of organic matter mineralization. The microbial consumption of monoand oligosaccharides, alcohols, and water-soluble compounds increases in the presence of wireworms (multisubstrate test). The effect of Elateridae larvae on the microorganisms transforming nitrogen compounds is species-specific. Agriotes obscurus activity decreases their consumption of urea and creatinine by 2.1–2.5 times, and Selatosomus aeneus increases it by 1.3 and 2.5 times, respectively. The intensity of actual nitrogen fixation in the soil increases in the presence of wireworms by almost 4 times, but the losses of gaseous nitrogen do not increase because of the decrease in both the denitrification and methanogenesis rates.

Проведен анализ пространственного распределения личинок жуков Elteridae в долине нижнего течения Иртыша. Выявлено 19 видов, личинки которых развиваются в почвах поймы и коренной террасы. Отмечено, что наиболее толерантны к регулярным затоплениям почвы во время весенних паводков личинки Paraphotistus nigricornis, Agriotes lineatus, Limonius parallelus и Aplotarsus incanus. Установлено, что пойменные и террасные луга кардинально различаются по видовому составу. Как правило, в пойменных луговых почвах встречаются виды с широким топическим спектром, включающим в себя кустарниковые и лесные местообитания, в то время как на коренной террасе преобладают виды открытых местообитаний, в частности степной зоны. Отмечено, что показатели разнообразия широко варьируют в пойменных и террасных участках, но более высокое видовое богатство (индекс Менхиника) обнаружено в пойме.