Morphological characteristics of grubs: adult: body length 19 ~ 2 1mm, width10 ~1.3 mm, and the back of antenna is copper green with metallic luster. There are four inconspicuous longitudinal ribs on both sides of the wing sheath, and the arm plate is triangular and yellow-brown, with a large black spot of inverted triangle at the base and an oval black spot on both sides.

Eggs: The newly hatched eggs are milky white, oval and round before hatching, and the surface of the eggshell is smooth.

Larvae: The 3rd instar larva has a body length of 30 ~ 33mm, a head width of 4.9 ~ 5.3mm, a yellowish brown head and a milky white carcass, with 6 ~ 8 bristles arranged in a row on each side of the head.

Pupa: The body length is about 18 ~ 22 mm, the width is 9.6 ~ 10.3 mm, and the body is slightly curved.