Identification
mouthparts plural noun - insect mouthparts are paired appendages (except for the labrum) used to acquire, manipulate, and chew food. The principal insect mouthparts are, starting from the topmost:
labrum - a
sclerite (horny plate of the body) that serves as the "upper lip". Sometimes the labrum is not considered to be a true mouthpart.
mandibles - analogous to the vertebrate jaw, these are used to cut and chew food, as well as for other purposes
maxillae - used in a manner similar to mandibles, but more complex in function, usually have attached maxillary
palpi, used for sensing and manipulating food. In some groups, the maxillae are modified into a
proboscis.
labium - a fused pair of appendages, analogous to the lower lip, often has attached labial
palpi. In some groups may be modified into a
proboscis. The tip of the labium is modified in some flies as a sop for liquids, the
labellum.
Diagrams and photos showing mouthparts:
Remarks
Note that some names of arthropod mouthparts were originally terms for an
analogous (but not
homologous) vertebrate structure.
Internet References
Mouthparts and Moving--Gary Brewer, North Dakota State University (excellent illustrations and descriptions)
