GENERAL TERMINOLOGIES ANTERIOR: towards the front (head) of an organism. CHITIN: outer covering which forms an external skeleton DISTAL: away from the body of an organism. DORSAL: the top (back) of an organism. ECDYSIS: casting of exoskeleton LATERAL: the sides of an organism. MEMBRANE: the soft, flexible areas between the sclerites. NOTUM: the dorsal surface of a thoracic segment. POSTERIOR: towards the rear (tail) of an organism. PLEURON: lateral plate between the tergum and sternum PROCTODAEUM: posterior part of the alimentary tract PROXIMAL: near the body of an organism. SCLERITE: individual hardened areas of an insect. STERNUM: the ventral surface of a thoracic or abdominal segment. STOMODAEUM: anterior part of the alimentary tract TERGUM: the dorsal surface of an abdominal segment. VENTRAL: the bottom (belly) of an organism. HEAD VERTEX: the top (dorsal) region of the head between the compound eyes. FRONS: region of the head below (anterior of) the vertex, above (posterior of) the clypeus, and between the genae. GENAE: the regions on the lateral aspects of the head; insect "cheeks". CLYPEUS: rectangular sclerite below (anterior of) the frons a nd above (posterior of) the labrum. HEAD APPENDAGES ANTENNAE COMPOUND EYES (adults only). OCELLI: small pits or bumps between the compound eyes (not on all insects) LABRUM: upper "lip" of insect; located below (anterior of) the clypeus. MANDIBLES: opposable "jaws" of insect; located below (anterior of) labrum. MAXILLAE: food handling structures, located below (anterior of) the mandibles. MAXILLARYPALP: antenna-like structure attached to each maxilla. LABIUM: lower "lip" of insect, located below (anterior of) maxillae. LABIALPALP: antenna-like structure attached to each side of the labium. THORAX PROTHORAX: thoracic region posterior of the head; contains one pair of legs. MESOTHORAX: thoracic region posterior of prothorax; contains one pair of wings and legs. METATHORAX: thoracic region posterior of mesothorax; contains one pair of wings and legs. WINGS: found on most adult insects, of various shapes and designs. THORACIC LEG SEGMENTS COXA: proximal leg segment, usually quite small. TROCHANTER: very small leg segment between coxa and femur. FEMUR: usually the longest leg segment; between trochanter and tibia. TIBIA: leg segment between the femur and tarsus. TARSUS: distal leg segment; composed of several tarsal segments and a claw. ABDOMEN SPIRACLES: external respiratory openings found on both thorax and abdomen, but much more conspicuous on the abdomen. PROLEGS: fleshy outgrowths used for locomotion, found primarily in larvae of the hymenoptera and lepidoptera. CERCI: antenna-like structure at the very end (posterior) of the abdomen, found in various insect groups. OVIPOSITOR: found at the very end (posterior) of the abdomen in females of various insect groups, variable in shape and size
