Female sperm storage

It has several documented biological functions including: One important advantage female insects that store sperm gain is increased genetic diversity in their offspring.

[21] Studies have also shown that ovipositing is nonrandom and females lay eggs with varying PGM(phosphoglucomutase) genotypes in different environments in order to optimize offspring success.

[22] Females possess remarkable abilities to select sperm to store and to fertilize their eggs that will make their offspring diverse.

At the microscopic level, Drosophila males have differing sperm tail lengths that correspond to various sizes of female seminal receptacles.

As a result of clutches with greater variation in paternal genes and increased sperm competition, females can maximize both the genetic quality and number of offspring.

Males of this species have developed behaviors, such as abdominal tapping, to increase their number of sperm stored in the favored storage site.

[35] Evidence for this pattern of storage, cryptic choice, and male behavior also exists in the flour beetle Tribolium castaneum.

[36] Some species, such as Egernia striolata, not only utilize sperm storage selection to improve fitness of their offspring, but to give them the upper hand in the event of sexual conflict.

[37] Muscle contraction as a means of moving spermatozoa through the reproductive system into and out of the storage structures has been examined in Diptera, Orthoptera, and Lepidoptera as well as in the species Rhodnius prolixus and the boll weevil.

[38] Male secretions, such as the glycoprotein ACP36D in Drosophila, can also play a role in preparing the female reproductive system for sperm storage.

The nervous system may signal for muscular contractions, fluid absorption, and hormone release, all of which aid in moving the sperm into the storage organs.

In the migratory locust (Locusta migratoria), the presence of an egg in the genital chamber results in an increase of spermathecal contractions.