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The Hawthorn Shield Bug (Heteroptera) has been used to illustrate the anatomy of the Hemiptera. The Homopteran bugs do not have hemyletral forewings and their wings are held over their abdomen in a tent-like manner, not flat as in the Heteroptera.
Anatomy of a Shieldbug Abdomen: the rear section of the body. Antenna(e): these are segmented and vary in the number of segments according to the family (five in Pentatomidae). Central lobe: the head is divided into three lobes. The shape and size of the central lobe is a useful identification feature in several species. Clavus: the inner part of the wing adjacent to the scutellum. Compound eye: multi-faceted (has many lenses). The eyes are positioned on each side of the head. Connexivum: lateral extension of the abdomen. Corium: the main area of the toughened and opaque base of the forewing. Coxa: the first small segment (from the body) of the leg. Cuneus: the most distal part of the toughened and opaque base of the forewing. Distal: furthest from the base. Dorsal or Dorsum: the upper surface of the insect. Femur (plural –femora): the third division (large upper section) of the leg. Hemelytron: this is the forewing of heteropteron bugs (including the shieldbugs). These bugs have their wings divided into two parts: -the toughened basal part which consists of the corium, clavus and cuneus. There are ‘fractures’ between these areas which give flexibility to the wing. -the distal part which consists of the hemyletral membrane (the clear tip). Instar: the larval stage between two successive skin moults. There are several instars and the larva may have an entirely different pattern or colour during each instar. Legs: consisting of fore-legs, mid-legs and hind-legs. Each of these is divided into 5 parts: (from the base) the coxa, trochanter, femur, tibia and tarsus. Ocelli: these two organs on the top of the head are simple eyes (some Hemiptera have three). Ovum (plural ova): the egg. Oviposite: to lay eggs. Pronotum: this is the large structure saddling the thorax. In many of the shield bugs it is has thorn-like lateral extensions.
Punctures:
small depressions over the surface of the bug. Rostrum: the modified mouthparts, which are used for piercing and sucking plant or animal matter. In the Heteroptera the rostrum is at the front of the head (as in the glossary picture of the Birch Shieldbug). This is due to a projection of the cuticle behind it called the gula. The Sternorrhyncha and Auchenorrhyncha do not have a gula, so their rostrums are set back under the head. How far it is set back defines to which suborder the bug belongs. Scutellum: this is the central plate set at the back of the pronotum. The scutellum is usually triangular, but is sometimes parallel sided and enlarged. It totally covers the wings in some species. Sternites: plates on the ventral surface of the abdomen. Stridulation: rubbing two parts of the body together to produce a noise or ‘song’. Strigil: a structure on the wing of some bugs that is used for stridulation. Tarsus (plural –tarsi): the foot, fifth or last division of the leg (which is itself segmented). There are three segments to the tarsus in the Pentatomidae. Tergites: plates on the dorsal surface of the abdomen. Thorax: the middle section of the body behind the head and in front of the abdomen. Tibia (plural –tibiae): the fourth division (from the body) of the leg. The section between the femur and the tarsus. Trochanter: the second small segment (from the body) of the leg. Tubercles: small raised ‘bumps’ scattered over the surface of the insect. They may have hairs protruding from them. Ventral: the underside of the insect. |
