Species composition and aphid population seasonal dynamics in vegetable agrocenoses of St. Petersburg and Leningrad region

Abstract

The purpose of this work was to study the species composition, the dynamics of aphid abundance in vegetable agrocenoses of the Pushkin district of St. Petersburg, as well as Tosnensky and Gatchina districts of the Leningrad region in the conditions of 2021-2022, significantly differing in weather conditions. The catching of insects was carried out using a Malaise trap. In total, during the two-year monitoring period, 40 species of aphids were registrated in the three studied agrocenoses, of which 28 are pests of agricultural crops. The total number of identified species in 2021 was 9 in each of the three research areas; the total number of captured insects was 99. At the end of May – beginning of June, the migration potential of aphids was high, active migration to secondary hosts was observed, however, abnormally high daytime temperatures in June – July with minimal precipitation had a detrimental effect on phytophages. In the weather conditions favorable for the development of aphids during the growing season of 2022, 11 species of aphids were caught in the Pushkinsky district of St. Petersburg, 12 in the Gatchina district, 20 in the Tosnensky district, that is, an increase in the species composition of phytophages was 2.2 times compared to 2021. In 2022, 279 individuals were registered; the largest number of insects was noted in the Tosnensky district – 171. In all the studied agrocenoses, the most numerous of the harmful species was the gray svidin-cereal aphid Anoecia corni F., damaging the roots of perennial grasses (the maximum number of 128 individuals in the Tosnensky district in 2022). A significant number in the same year was observed in the pea Acyrthosiphon pisum Harr., as well as in the cabbage aphid Brevicoryne brassicae L. Quite rare species of aphids for the North-Western region were recorded in the agrocenosis of the Pushkin district: Oxton and maple aphids. The pink tansy aphid was registered only in the Tosno agrocenosis in June 2022. The Malaise trap proved to be convenient to work with, since it is not stationary, can be installed anywhere in any agrocenosis. It can be recommended to use it, first of all, to assess the species diversity of insects, and secondly, to estimate the number.