New data on consortive associations of Sosnowsky's hogweed with anthophilous insects.
The interactions of anthophilous insects with Sosnowsky's hogweed in Moscow oblast were studied. Sixty-nine species that visited Heracleum sosnowskyi inflorescences were identified. Comparative analysis of insects collected from Sosnowsky's hogweed in different areas of Moscow oblast and those listed in earlier studies revealed low reproducibility of species composition of insects collected on the inflorescences of this plant. Therefore, quantitative censuses of insects visiting hogweed presumably deserve more attention than qualitative censuses made within the same studies. Insect species diversity on hogweed inflorescences was higher than that registered simultaneously for Seseli libanotis, another umbelliferous plant. The role of different anthophilous insect groups in the pollination of Sosnowsky's hogweed was inferred from the analysis of behavior and the location and amounts of conspecific pollen on the bodies of visitor insects.