Development of livestock as well as increase of milk and meat production depends considerably on prompt and qualified veterinary measures. One of the reserves of lifestock profitability rise is prevention of infectious diseases including entomosis, and animals' protection from bloodsucking dipterous insects: deer flies, mosquitos, gadflies and biting midges also known as gnats. In Belorussia dairy cows lost up to 15–20 % of milk and in single seasons up to 30–40 % due to bloodsucking dipterous insects attack. The task of present research is the study of insecticide efficacy of drugs: Delcid, Almet, Fenmet, Breeze 25 % applied as aerosols using ultra low-volume spraying when cattle in pastures are massively attacked by gnats. The repellent efficacy of drugs Breeze-Prof, Polevik, Phytolym, Tobol and Alezan spray against gad-flies are studied. While using of ultra low-volume hitch spraying of young cattle herds: 0,05 % solution of Delcid, Almet, Fenmet, Breeze 25 % at the rate of 10 ml per cattle it is found that the protective action coefficient according to average data related to gadflies family Tabanidae within first 30 minutes makes: for Delcid – 92,49 %, Almet – 100, Fenmet – 100, Breeze 25 % – 95,3 %, and within 24 hours: Delcid – 81,7 %, Almet – 71,4, Fenmet – 56,2, Breeze 25 % – 81,8 %.Изучено действие некоторых репеллентов и ин-сектицидов, рекомендуемых против гнуса. Разрабо-таны режимы их применения, проведены широкие производственные испытания и рекомендованы для практического применения наиболее эффективные и безопасные препараты на основе синтетических пире-троидов. Проведенными исследованиями изучена репеллентная эффективность против слепней семейст-ва Tabanidae новых препаратов, которые показали удовлетворительную эффективность
