In this brief communication, the results of the research on the seasonal dynamics of orthopterous insects (Orthoptera) are discussed. The research was performed in the Volga-Kama State Nature Biosphere Reserve. Field sampling and observations were carried out for different biotopes of the nature reserve. The phenological characteristics of 26 background species of the families Tettigonioidea, Tetrigidae, and Acridoidea were revealed. The species under study were divided into five phenological groups: spring-summer, early summer, summer summer-late summer, and late summer. Most species belonged to the summer-late summer group. The highest species diversity was observed from the middle of July to the end of August. Furthermore, five seasonal aspects influencing the population dynamics were singled out based on the obtained results: late spring, early summer, summer, late summer, and autumn. The periods of all the successive aspects were identified. It was discovered that development proceeds non-uniformly for different biotopes. The delay may be up to one decade. For some biotopes, the seasonal aspects, such as the early-spring one, were not observed at all. The results were compared with the data from similar studies performed in Kirov oblast neighboring the Republic of Tatarstan. In general, the development periods differed insignificantly. In Kirov oblast, a slight delay occurs in the development of some phonological groups.