Leningrad Region Becomes Leader in Microplastic Concentration in Wasps

Biologists from Tomsk State University determined the concentration of microplastics in wasps. The insects collected in Leningrad Oblast had the highest concentrations. The results of the study, which were reported by the Russian Ministry of Education and Science, are presented in an article in the Euroasian Entomological Journal.

Biologists examined more than 460 wasps from six countries. The analysis showed that the highest concentration of microplastic particles was found in the Leningrad Region, and the lowest in Crimea, the South Kazakhstan Region, and the Matruh Province in Egypt.

“The object of our research was wasps of three genera: hornets (Vespa), short-cheeked wasps (Vespula) and paper wasps (Polistes), says Anastasia Simakova, head of the Department of Invertebrate Zoology at the TSU Biological Institute.

According to her, 466 individuals collected in Russia, Central Asia, Mongolia, Primorye and Egypt were examined for microplastic contamination. Synthetic fibers of different lengths in black, blue, orange, red, and colorless fibers were registered in the insects. All of them presumably got into the intestines of the wasps during feeding and nest building.

As noted in the article, the accumulation of microplastics by wasps varies in different regions. The place with the highest levels of its content in wasps was the Leningrad Region. The average number of microplastic particles per individual there was from 2 to 6 units. Quite a high content of particles was also recorded in wasps collected in Primorsky Krai and Sakhalin Region. But the intestines of wasps living on the Crimean Peninsula, in the South Kazakhstan Region and in the Matruh Province of Egypt turned out to be the cleanest from microplastics.

The most common type of particles found in the wasps' bodies were transparent and black fibers about a millimeter long (the latter were counted the most - 173 particles, or 30.6% of the total number of particles).

Their source is most likely textile industry items.

– We found out that terrestrial insects can accumulate microplastics and anthropogenic fibers and participate in their distribution in terrestrial ecosystems, – notes Anastasia Simakova. – Presumably, wasps consume microplastics during feeding (from rotten fruits, larvae of other insects) and building nests (paper industry waste, wood).

Of great interest to scientists is how microplastics in the gut can affect the health of insects. In their opinion, its accumulation in the body is dangerous due to nutritional deficiency, since the presence of microplastic particles in the gastrointestinal tract causes insects to have a false sense of satiety and, as a result, reduce food consumption.

The next step in studying the accumulation of microplastics in living organisms will be to study the morphological features of contaminated insects, such as the color of the abdomen or the structure of the wings.