Henosepilachna vigintioctomaculata Motschulsky (Coleoptera: Coccinellidae): morphotypes in an East Asian population

Abstract

The 28-spotted potato ladybird beetle Henosepilachna vigintioctomaculata is an endemic pest of field crops in the Russian Far East. The study on the morphotypic structure of a population of this phytophagous insect can facilitate the monitoring of processes occurring in ecosystems. It might contribute to the research on the endemic fauna of the Russian Far East and reveal how varieties form resistance to pesticides. To study the polymorphism and structure of a potato ladybird beetle population, an analysis of elytral color patterns was conducted. The following features were considered: the size and shape of spots, the intensity of color, the position of spots on the elytra relative to the elytral suture, the presence of merged spots. As the result, nine morphotypes were identified. The morphotype A2 was the most frequent (47.81 %) and followed by the morphotypes A1 and A6. The morphotype A9 had the lowest frequency of occurrence (1.82 %). It was also determined that morphotypes differed in the linear dimension of spots on the elytra. The form A2 was characterized by the largest spots. The size of the color patterns varied from 104.98 ± 0.071 to 297.01 ± 0.065 µ. The form A1 had the smallest spots.