Core factors influenced the number of blood-sucking midges (Diptera, Simuliidae)
Abstract
Introduction: The article presents the results of many years of research, a study of the breeding sites of bloodsucking diptera in the south of the Tyumen region, and the influence of environmental factors on the number of preimaginal phases of development of these insects. Materials and Methods: The collection and counting of the number of the preimaginal phases of diptera was carried out according to accepted methods. The results showed that in the south of the Tyumen region the main breeding grounds for diptera are the Iset and Pyshma rivers and small rivers and streams. Depending on the season, the number of midges can undergo significant changes, which is because of the hydrological regime of the rivers. The maximum density of larvae and pupae-390 individuals per 1 dm2 of substrate was recorded in 2007, the minimum was noted in 2006 and 2014, it ranged from 2 to 97 individuals/dm2, when the spring increase in the water level in the rivers was insignificant, the low number of larvae and pupae was due to the prevailing meteorological conditions in these years. The major factors hindering the development of diptera in a reservoir are the low speed of water flow, turbidity, and pollution with industrial and domestic waste. Conclusion: the factor limiting their number is the slow speed of water flow; that is why the practice of building dams on small rivers, in order to create reservoirs for watering animals in pastures, ensures the limitation of the number of larvae and pupae of diptera.