In 1983, Oleg Pavlovich defended his thesis for the scientific degree of Doctor of Biological Sciences (DSc in Biology), dedicated to the system and phylogeny of Dolichopodidae of world fauna, and since 1986, he took the position of professor of the Chair of Invertebrate Zoology. Later he became the head of this department, which was transformed under his leadership into the Chair of Ecology and Systematics of Invertebrates. Since September 2020, after merger of two zoological departments, he became a professor at the Chair of Zoology and Parasitology.
O.P. Negrobov was the head of the Department of Ecology and Systematics of Invertebrate Animals, the Chairman of Voronezh Branch of Russian Entomological Society, the Chairman of Commission of Ecological Education attached to the council of Rectors of Institutes of High Education in Central Black Soil Region, the Chairman of Voronezh Branch of Russian Ecological Academy, the academician of Russian Ecological Academy, the member of Councils of thesis' defence in speciality Ecology in Voronezh State University and in Academy of Forestry and Technology, the Head of the Society of Nature Protection of Voronezh-city, the member of two inter departmental commissions on Ecological Education and Ecological Security attached to the Regional Administration, the member of Co-ordinating Council on Ecological Education of Student and Pupils attached to the Regional Department of Education, the member of Problematical Council on Ecological Education attached to the Branch of General Secondary Education of Russian Academy of Education, the (assistant director) and head of Department on Ecological Education of Eco-centre of the Voronezh University, the supervisor of studies of educational-scientific biological Centre Venevitinovo of Voronezh State University, the Chairman of Voronezh Department of inter-institutional Centre on working out the technologies of ecological education (The Centre of Technologies of Ecological Education in Moscow), the member of American ecological club Sierra, the member of Russian Interdepartmental scientific-technical Council on apidology and bee-keeping attached to the Russian Academy of Apiculture, the Chairman of independent social ecological organisation Ecodon.
Since the first years of his work until the end of his life, he was
engaged in research on dipterans. And he was one of the world's leading
specialist on the long-legged flies (family Dolichopodidae). He described
13 new genera, about 510 new species and subspecies of this family.