labium noun, plural labia, adjective labial - the "lower lip" of the arthropod mouth. It closes the orifice of the mouth from below. Sometimes called the "tongue", and is regarded as a "second maxilla" because its structure is derived from the fusion of two maxilla-like appendages. The labium consists of two parts, the mentum and the ligula. In some groups, the labium is modified for sucking liquids as a proboscis. In some flies, the tip is modified for sopping liquids as a labellum. There are often labial palpi (sensory organs) attached.

(The plural labia would not be used for insects, since there is only one labium. The "upper lip" is the labrum.)

Diagrams and photos showing the labium:

See Also

mouthparts

labrum

mandibles

maxillae

labium (labellum, ligula, mentum, labial palpi)

proboscis

Print References

Gordh, A Dictionary of Entomology, p. 502 (1)

Internet References

Jardine's Dictionary of Entomology

Works Cited

1.	A Dictionary of Entomology George Gordh, David H. Headrick. 2003. CABI Publishing.

Contributed by Cotinis on 19 May, 2007 - 2:30am
Additional contributions by Lynette Elliott
Last updated 6 December, 2011 - 6:06pm

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