Neural and hormonal control of muscular activity of the spermatheca in the locust, Locusta migratoria

The spermatheca in insects is a tubular structure within the female that acts as a repository for spermatozoa deposited by the male during copulation. The spermatozoa remain viable within the spermatheca for extended periods of time, and are then delivered to the site of fertilization during oviposition (egg-laying). Thus, the production of viable offspring is dependent upon the coordination of events associated with fertilization, including the passage of the egg through the lateral and common oviducts and the passage of spermatozoa along the spermathecal duct. The egg and the spermatozoa are propelled along their respective tracts by contractions of the visceral muscles intrinsic to the oviduct and spermatheca. The neural and hormonal control of muscular activity of the locust oviducts has been well reviewed, with more recent studies examining the control over the spermatheca. This review highlights more recent literature, including new data, for neural and hormonal control of muscular activity of the spermatheca of the locust, Locusta migratoria, making reference to examples in other insects where relevant. A variety of neuronal types project to the spermatheca in L. migratoria, and a variety of neuroactive chemicals, including neuropeptides and amines, influence contraction. A comparison is made between the control of oviducts and spermatheca in L. migratoria with regard to their neural substrate and the composition of neuroactive chemicals.