Aphids have tubular protrusions (abdominal tubes) on their abdomen. Aphids have a pair of abdominal tubes, which are used to discharge defense fluids that can quickly harden. The composition is triglyceride. The abdominal cavity tube is usually tubular, long and usually wide, with a thick bottom. They suck plant juice and are large plant pests. It not only hinders the growth of plants, forms galls and spreads viruses, but also causes deformities of flowers, leaves and buds.
Morphological characteristics:
Body length 1.5 ~ 4.9 mm, mostly around 2 mm, sometimes with wax powder, but lacking wax flakes. The antenna has 6 nodes, few 5 nodes and rare 4 nodes. It feels round, rarely oval, and the end of the terminal segment is often longer than the base. The eyes are big and small, and there are often three prominent microphthalmos. Beak tip short, blunt to long. The abdomen is larger than the sum of the head and chest. There are often tumors in the chest and abdomen.
The ventral tube is usually tubular, longer than the width, thicker at the base, tapering gradually towards the end, sometimes swollen at the middle or the end, with prominent edges at the top, smooth surface or corrugated or reticulated at the end, and few hairs or annular or missing ventral tubes.
The tail is conical, finger-shaped, sword-shaped, triangular, pentagonal, helmet-shaped to half-moon-shaped. The end is round. The epidermis is smooth, reticulate or wrinkled, or has thorns or mottled particles.
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