Hemipteran insects are commonly known as "bugs". There are more than 38,000 known species and they are also one of the larger groups in the Insecta. The forewings of the Hemiptera are covered on the back of the body when at rest, and the hind wings are hidden Underneath, because the base of the forewings of some groups is ossified and thickened, becoming a "hemi-elytra" state, they are named "Hemiptera" and are hemimetabolous insects.

1. Mouthparts: The mouthparts are of a piercing and sucking type, extending from the front of the head and extending backward along the belly of the body when resting. They are generally divided into 4 segments; the antennae are longer and generally divided into 4 to 5 segments. nodes; the pronotum is large, and the small scutes on the mesothorax are well developed; the base half of the forewing is ossified, and the end half is membranous, and is a hemi-elytra; many species have odor glands, opening on both sides of the ventral surface of the thorax and the back of the abdomen.

2. Wings: There are two pairs of wings, the forewings are semi-elytra and the hind wings are membranous. Most species have well-developed odor glands, and their secretions (components of 2-hexenal, 2-octanal, 2-decenal, etc.) volatilize in the air, producing abnormal odors, which can be used for defense. The head is mostly triangular or pentagonal in shape. The center of its front end is called the middle piece, and its two sides are called the side pieces. Deuterostome, piercing-sucking mouthparts, beak tube usually has 3 to 4 segments, but unlike Homoptera, the white head at the base of the beak protrudes in front.

3. Antennae: The antennae have 4 to 5 sections, mostly filamentous. The compound eyes are well developed and protrude on both sides of the head; there are 2 single eyes, located behind the compound eyes. A few species have no single eye. The pronotum is well developed and usually hexagonal; some have a long neck shape with horn-like protrusions on both sides. The small scutes on the middle chest are well developed, usually triangular, or semicircular or tongue-shaped. Some species are particularly well developed and can cover the entire abdomen. There are usually two pairs of wings. The base of the forewings is thickened into leather and the ends are membranous, so they are called hemi-elytra. The leathery part is often divided into leather pieces, claw pieces, edge pieces and wedge pieces; the membranous part is called a diaphragm, and the number and arrangement of the veins of the diaphragm vary with different species. The hind wings are membranous and the wing veins vary greatly.

4. Feet: The types of thorax feet often change due to different habitats and feeding habits. In addition to the basic type of walking feet, there are also catching feet, swimming feet and digging feet. The tarsus has 3 segments, occasionally 2 or 1 segment, and has 2 claws. Most species have odor glands, which open on the lateral plate of the posterior thorax near the base of the hind legs. The middle and posterior thorax each have a pair of valves. The abdomen is usually 10 segments. The meeting point of the dorsal plate and the abdominal plate forms a prominent ventral edge, called the lateral edge, without tail whiskers. Segments 1 to 8 each have a pair of spiracles on the ventral surface, indicating that aquatic species may have breathing tubes. The female genital pore opens at the eighth abdominal segment, and the ovipositor consists of two pairs of egg-laying valves, lacking the third egg-laying valve.