Spermatheca

: receptacula seminis), is an organ of the female reproductive tract in insects, e.g. ants, bees,[1] some molluscs, Oligochaeta worms and certain other invertebrates and vertebrates.

[4] They are lined with epithelium and are variable in shape: some are thin, heavily coiled tubes, while others are vague outpocketings from the main reproductive tract.

[5] The C. elegans spermatheca is made up of 24 smooth muscle-like cells that form a stretchable tubular structure.

[7][8] An apiculturist may examine the spermatheca of a dead queen bee to find out whether it had received sperm from a male.

[9] In many species of stingless bees, especially Melipona bicolor, the queen lays her eggs during the provisioning and oviposition process and the spermatheca fertilizes the egg as it passes along the oviduct.