entomology Entomology (from Ancient Greek ἔντομον (''éntomon''), meaning "insect", and -logy from λόγος (''lógos''), meaning "study") is the branch of zoology that focuses on insects. Those who study entomology are known as entomologists. In ...

, the term labellum has been applied variously and in partly contradictory ways. One usage is in referring to a elongation of the labrum that covers the base of the rostrum in certain

Coleoptera Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

and

Hemiptera Hemiptera (; ) is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from ...

. In contrast, the most common current use of the term is in the anatomy of the mouthparts of

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...

, particularly those in which the labium forms the bulk of the proboscis, such as in the housefly family. Typically, the labium is expanded distally into a pair of fleshy labella. In the early twentieth century it was argued that the labella are the modified labial palps, and that point of view still is seen as having merit. In flies such as the mosquitoes, that have long antennae, the labella are two separate organs, attached to the proboscis only at their bases, but in the flies with short antennae, such as the house fly, they are more or less fused to form a single structure. Flies with fused labella have food channels in the surface of the labella. These are called ''pseudotracheae''. They form the "spongy" part of a housefly's "tongue".

References

Insect anatomy {{insect-anatomy-stub

See also

References