The metasoma is the posterior part of the body, or tagma, of
arthropods whose body is composed of three parts, the other two being
the prosoma and the mesosoma. In insects, it contains most of the
digestive tract, respiratory system, and circulatory system, and the
apical segments are typically modified to form genitalia. In a few of
the most primitive insects (the Archaeognatha), the metasomal segments
bear small, articulated appendages called "styli", which are often
considered to be vestigial. There are also pre-apical appendages in
most insect orders, called cerci, which may be multi-segmented and
almost resembling a posterior pair of antennae; these may be variously
modified, or lost entirely. Otherwise, most adult insects lack
appendages on the metasoma, though many larval insects (e.g.,
caterpillars) have some form of appendages, such as prolegs or, in
aquatic insects, gills.
^ a b D. R. Khanna & P. R. Yadav (2004). "Segmentation in
arthropods". Biology of Arthropoda. Discovery Publishing House.
pp. 316–394. ISBN 978-81-7141-897-8.
^ Donald L. J. Quicke (2009). "