Glossary

Antennae: these are segmented and vary in the number of segments according to the family (five in Pentatomidae).

The basic segments of the typical insect antenna are

The scape or scapus (base): This is mounted in a socket in a ring-shaped sclerotised region called the torulus, often a raised portion of the insect’s head capsule. The socket is closed off by the membrane into which the base of the scape is set. The antenna pivots by a projection called the antennifer on a rigidly sprung projection from the rim of the torulus. This arrangement enables the insect to move the entire antenna by applying internal muscles connected to the scape.

The pedicel is flexibly connected to the distal end of the scape and its movements in turn can be controlled by muscular connections between the scape and pedicel. It contains the Johnston’s organ     which is a collection of sensory cells.

The flagellum, which often comprises many units known as flagellomeres.

Antenniferous tubercle: Discrete, typically cylindrical areas on the sides of the head, to which the basal segments of the antennae are attached.

Buccula: the vertical plates of the head arising ventrally on either side of the base of the labium.

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.

Claval commissure: The line where the two clavi meet –  lies to the posterior of the scutellum.

Clavus: the inner part of the wing adjacent to the scutellum.

Clypeus: The clypeus is one of the sclerites that make up the “face” of a shieldbug; it delimits the lower margin of the face, with the labrum articulated along its ventral margin.  Its dorsal margin is located below the sockets of the antennae.

Collar: The anterior part of the pronotum typically separated from the distal part by a groove.

Compound Eye:  an eye made up of individual units called ocelli. The transocular width is the space on the dorsum of the head between the two compound eyes.

Connexivum: Lateral extension of the abdomen., sometimes visible at rest. It may be flat, or turned upward. In some it has alternating bands of colour.

Corium: The toughened and opaque base of the forewing lying between the clavus and the membrane when the insect is at rest.

Cuneus:  The most distal part of the toughened, opaque base of the forewing – a small triangular area, typically turned downwards, seen in the Miridae.

egs: Each is sub-divided into 5 parts – coxa (nearest the body), trochanter, femur, tibia and tarsus (bearing claws).

Trochanter: The second (as counted from the body of the insect) segment in the leg of an insect and is located between the coxa and the femur.

Femur: The third (counting from the body) segment of the leg. located between the trochanter and the tibia.

Tibia: The middle section of the leg located between the femur and the tarsus. At its basal end the tibia is attached to the femur; at its apical end the tibia is attached to the tarsus.

Tarsus: The apical section of the leg; the “foot.” At its basal end the tarsus is attached to the tibia.

Claws: These are the final (furthest from the body) segment in the leg of an insect.

Membrane: this refers to the membranous ends of the wing which is hardened at the base.

Mesothorax:  the middle of the three segments in the thorax of an insect, and bears the second pair of legs. Its principal sclerites (exoskeletal plates) are

the mesonotum (dorsal)`

the mesosternum (ventral),

the mesopleuron (lateral) on each side.

Ocelli: Simple eyes, usually two on top of the head, some have three. Their number and distribution is used in some keys to family and subfamily.

Ostiole: The scent gland opening.

Pronotum: The dorsal plate between the head and the scutellum. In some shield bugs it has spiny lateral extensions. It is subdivided into the Anterior and Posterior Pronotal Lobes.

Prothorax: the foremost of the three segments in the thorax of an insect, and bears the first pair of legs.

Its principal sclerites (exoskeletal plates) are

the pronotum (dorsal),

the prosternum (ventral)

the propleuron (lateral) on each side.

Punctures: Small depressions over the surface of the bug.

 Rostrum (pl. Rostra): The beak. Located at the front of the head –  modified mouthparts, used for piercing and sucking plant or animal matter.

Scutellum: The central plate at the back of the pronotum and normally between the bases of the hemelytra. It is usually triangular, but sometimes parallel sided and enlarged. It totally covers the wings in some species.

Scutellar suture: A transverse line on the scutellum, typically near the centre.

 Sternites: Plates on the ventral surface of the abdomen.

 Striae: Longitudinal lines on the body surfaces.

 Tergites: The dorsal surface  plates of the abdomen.

Transocular width: The space between the two compound eyes.

 Tubercles: Small raised ‘lumps’ scattered over the body surface sometimes bearing protruding hairs.

 Tylus: The area between the juga.

 Vertex: The dorsal surface of the head (excluding the eyes)