Identification and Control Methods for the Potato Ladybird Beetle

The potato ladybird beetle (Henosepilachna vigintioctomaculata Motschulsky) belongs to the order Coleoptera, family Coccinellidae. It is widely distributed in northern China. It mainly damages potatoes, eggplants, Chinese cabbage, rapeseed, as well as beans, cucurbits and so on.

[Field identification] Both adults and larvae feed on leaves, gnawing the epidermis and mesophyll on one side, creating many net-like pits. The adult is about 8 mm long and hemispherical. The body dorsum and elytra are yellowish-brown. The center of the pronotum has 1 sword-shaped black spot. There are 2 black spots on each side. Each elytron has 14 black spots, of which 3 spots are at the base of the elytron, and the 4 spots behind them are not in a straight line. When the larva is fully grown, its body is about 9 mm long, yellow, spindle-shaped, with a swollen middle and a raised back; each segment on the dorsal side bears black branched spines, and each branched spine also has 6 to 8 small spines.

[Occurrence pattern] It occurs 1 to 2 generations a year, overwintering as adults gathered in stone crevices, wall cracks and caves that are sheltered from the wind and face the sun. In mid-to-late May of the following year, the overwintering adults begin activity, and mid-to-late June and August to September are the peak damage periods. The adults are active during the day and have a habit of playing dead; when disturbed, they drop to the ground and remain motionless, secreting a sticky fluid. The larvae cluster to cause damage and move slowly.