Together with a few fellow graduate students and with the aid of Russian entomologists Drs.
Mirzayans' knowledge of several languages (including Russian, French and English), communication skills and perseverance led to scientific collaborations and exchanges with many entomologists and entomological institutions around the world and resulted in growth of the insect collection and creation of an entomological library.
Mirzayans specialized in taxonomy of Orthoptera of the Palaearctic region but had a keen interest in several other groups including Hemiptera (Auchenorrhyncha).
He retired in 1979 but continued to work in his office in the Insect Taxonomy Research Department until the end of his life.
During over 53 years of work, he trained many young entomologists, published many books and papers and described several new genera and species of insects for Iran.