Comparative Study of the Phenotypic Structure and Photoperiodic Responses of Female Asian Ladybirds Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae) from Moscow, Belgorod, and Sochi

Abstract

Abstract Insect invasions are often accompanied by changes in the phenotypic structure of the populations and in the photoperiodic responses that regulate seasonal cycles. The Asian ladybird Harmonia axyridis has been recently discovered in Krasnodar Territory, from whence it is now gradually colonizing Central Russia. Our comparative study of individuals collected in 2020 in Sochi, Belgorod Province, and Moscow Province shows that interpopulation differences in their phenotypic structure are nonsignificant. The proportion of the light morph succinea is 77–83%; the proportion of the most common dark morph, spectabilis, is 13–20%. Laboratory experiments show that females from all the studied populations exhibit only a weak photoperiodic response. Comparative analysis reveals that females from the more northerly Moscow and Belgorod populations have a somewhat greater tendency to diapause and slightly delay reproductive maturation.