Adults – 20mm long. They are shiny, dark–brown or black.
Larvae are honey–yellow, they have a smooth, highly polished, shiny, elongate, hard, worm-like body, and can grow to 30 mm long.
Lifecycle
Each female lays about 275–600 eggs singly or in clusters during the spring. They are white, bean-shaped and about 1mm long and hatch into larvae in 4 to 14 days.
The pupal stage lasts 7 to 24 days during the spring. Pupae are first white, turning yellow, and are not enclosed in a cocoon.
Adults emerge in the spring or early summer, living for two to three months.
Habits
They are highly resistant to cold temperatures.
Adult beetles are attracted to night-lights, are strong fliers, and are found in dark places.