The poplar can is the cocoon of an insect. The adult of this insect is called the brown-edged green moth. Its aliases are green-edged moth, brown-edged green moth, and four-spotted green moth. , Curved green moth. Folks also call it yellow thorn moth. Its larvae are commonly known as "Yang La Zi" or "Yang La Zi", and some people also call them "Yang La Zi".

Its scientific name is the yellow thorn moth. In winter, it makes sheep-drawn jars to hide in. The jars have patterns and come out in spring with venomous stingers.

Morphological characteristics: Adult female moths have a body length of 15-17 mm and a wingspan of 35-39 mm; male moths have a body length of 13-15 mm and a wingspan of 30-32 mm. Body orange-yellow. The forewings are yellowish brown, with a thin diagonal line extending from the top corner to the middle chamber. The inner side of the diagonal line is yellow and the outer side is brown. There is a dark brown thin line on the brown part extending from the nuchal corner to the middle of the rear edge. There is a yellow-brown dot on the chamber part. Hind wings grayish yellow. Egg is flat oval, slightly pointed at one end, 1.4-1.5 mm long, 0.9 mm wide, light yellow, with turtle-like carvings on the egg membrane. ?larvae? Mature larvae are 19-25 mm long and thick. The head is yellowish brown and hidden under the chest. The chest is yellow-green, starting from the second segment of the body, there is a pair of thorns on both sides of the dorsal line of each segment, with the third, fourth, and tenth segments being the largest. There are black thorns on the spines; there are large purple-brown thorns on the back of the body. The markings are wide front and back, with one middle part narrowing into a dumbbell shape, and 4 small brown spots on the back of the distal segment; there are 9 thorns on both sides of the body, and there are 2 blue vertical stripes in the middle of the body. The upper line of the valve is light blue, and the lower line of the valve is light blue. Light yellow. Pupa oval, thick. Body length 13-15 mm. Light yellowish brown, the back of the head and chest is yellow, and there are brown dorsal plates on the back of each section of the abdomen. The cocoon is oval, hard, dark brown, with gray-white irregular vertical stripes, very much like a sparrow egg.