Male reproductive organs consist of a pair of testes connecting with paired seminal vessels and a medial ejaculatory duc t . These are connected to the vas deferens and lead into the ejaculatory duct. Other insects have a great many as do the American cockroaches. Sperm are formed in the follicles .
Females have a pair of ovaries consisting of a variable number of ovarioles .
These connect to a pair of lateral oviducts , which join to form a median oviduct which opens into genital chamber. Sometimes this genitial chamber forms a tube, the vagina , which is often developed to form a bursa copulatrix for the reception of the aedeagus . In tse-tse flies, this chamber is enlarged to form a space where the young are raised until they are ready to pupate. Opening from the genital chamber is a spermatheca for storing the sperm . However, in many species the sperm is transferred without the aedeagus being inserted into the female.