The study of bloodsucking dipterans, including gadflies, was conducted mainly in the 60-70s of the last century, when the rapid development of oil and gas production began and was associated with the development of means and methods for the pro-tection of humans and animals. Since then, more than 40 years have passed. Dur-ing this time, there was a noticeable warming of the climate, and due to technical progress, the anthropogenic impact on nature increased. Currently, the interest of scientists and researchers to Diptera has significantly increased. Blood-sucking two-winged insects (midges) include mosquitoes (blood line Culicidae), gadflies (blood line Tabanidae), midges (blood line Simuliidae) and biting midges (blood line Cera-topogonidae). The main factors determining the high abundance of midges are favor-able climatic conditions for their reproduction and existence in combination with the abundance of biotopes of hatching (various water bodies and marsh formations) and the habitat of the imago (presence of tree, shrub or high grassy vegetation), as well as the presence of a sufficient number of warm-blooded animals – the source of blood saturation. The damage caused by horseflies to humans and animals is very great. The aim of our work was to summarize the information in the literature about the damage caused by horseflies to farm animals and their role in the transmission of pathogens of humans and animals.

A statistical assessment was made of the data for 2016 on the identified cases of oncological diseases and invasions by helminths of the genus Dirofilaria in population of different regions of the world using the statistical method and correlation analysis according to Spearman. The results of the correlation analysis showed an inverse relations between the invasion level and the number of diagnosed oncological diseases on most continents, except for countries of South America, where the relationship between the two studied pathologies was direct (0.314). However, the values of statistical correlation for South America can be considered as little informative, since the known statistics on infection with dirofilariasis is close to zero. The revealed correlation in other regions (Asia –0.15; Europe –0.486; Africa –0.85) suggests that as the prevalence of Dirofilaria helminths in population increases, fewer cases of oncological diseases are recorded and vice versa. At the same time, it should be considered that this relationship is influenced by many other factors, the main of which we can consider modern medicine. In general, the study of the relationship between Dirofilaria infection and the oncological disease requires further study

This article summarizes the available literature data on association of blood-sucking horseflies (Diptera, Tabanidae) with various abiotic factors (illumination, air temperature, wind and humidity). In recent years, studies on the daily and seasonal activity of horseflies in various territories of our country have been significantly expanded. The gnat complex includes mosquitoes (the family Culicidae), horseflies (Tabanidae), blackflies (Simuliidae) and sandflies (Ceratopogonidae). Factors that determine high abundance of the gnat are favorable climatic conditions for their reproduction and existence combined with abundance of breeding biotopes (various reservoirs and swamp formations), and habitat of adults (woody, shrub or tall herbaceous vegetation available), as well as a sufficient number of warm-blooded animals, a source of engorgement. The damage depends on high abundance of these insects and can adversely affect the health of farm animals and humans due to the transmission of infectious and invasive diseases. The development of effective measures to control horseflies based on the knowledge of biology of these insects, is one of the urgent tasks of agricultural science aimed at increasing animal productivity.

With the widespread infection of Dirofilaria repens in dogs on the territory of the Russian Federation, the morphological changes in this disease are not well described, and the carcinogenic effect of these helminths on the host has not been established. We have carried out a comprehensive study of morphological changes in the tissues of outbred dogs (the mammary gland of two females and the testes of one male) with subcutaneous dirofilariasis. Excised neoplasms were sent for histological examination, as a result, the females were diagnosed with papillary breast cancer with areas of chondroid differentiation, necrosis, diffuse type of growth, fibrocystic non-proliferative mastopathy. In the male, the histological diagnosis corresponded to chronic orchitis, sclerotic changes were expressed in the epididymis with atrophic and cystic changes in the vas deferens. The uniformity of the micromorphological picture of the neoplastic process in the mammary gland in females may have a certain relationship with the invasion of D. repens due to chronic mechanical traumatization of the host tissues by helminths, as well as their toxic and immune effects. The described impact, in our opinion, was the cause of dystrophy of the male reproductive glands. In general, the study of the relationship between infection with D. repens and the oncological process requires further, more in-depth and private study.

Recently, interest in paleoparasitology and archaeoparasitology has significantly increased all over the world, which served as the basis for the development of an international protocol for special parasitological studies, which needs to be tested and adapted for each specific case. In this work, we conducted a paleoparasitological study of 29 samples obtained during the excavations of the city of Mangazeya (north of Western Siberia) using the modified method of Beltrame M.O. et al. In the course of the analysis, 1977 slides with sediment were examined and more than 87 thousand helminth eggs were found. It was established that the prevalence of the infection was 89.66%, the average intensity of the infection was 3349.38, and the abundance index was 103.55. The presence of 9 species of parasites was determined, with eggs of some of them found in a very few number, including 4 species that were not found earlier on this site. Statistical processing demonstrated the relationship between the number of slides examined and the number of helminth eggs found, while the Spearman correlation coefficient was 0.658 with a significance value of <0.05. Comparison of the parasitological research methods of archaeological finds showed that the use of the method of analysis we chose demonstrates more reliable results and allows us to detect parasite eggs in the sample in an insignificant amount.