The propodeum is a term that can refer to unrelated structures in insects or in mollusks.
Insects
The first
abdomen segment in
Apocrita Hymenoptera (
,
and
) is known as the propodeum. It is fused with the thorax to form the
mesosoma. It is a single large
sclerite, not subdivided, and bears a pair of spiracles. It is strongly constricted posteriorly to form the articulation of the petiole, and gives apocritans their distinctive shape. There may be a suture between the propodeum and the thorax, like in
Symphyta or not, and the presence or absence of such suture can aid in identifying specimens.
Mollusks
Propodeum is the anterior (frontal) part of the foot of a mollusk.
Notes
