Parthenogenesis is a form of asexual reproduction in which offspring are produced from unfertilized eggs. The term derives from the Greek parthenos, meaning virgin, and genesis, meaning origin. Parthenogenesis is, literally, a virgin birth.
Parthenogenesis occurs to some degree in nearly all insect orders, but is particularly well known in the bees and wasps, in aphids, and in stick insects. Parthenogenetic reproduction can be either obligate (the species cannot reproduce sexually) or facultative (the species may alternate between sexual and asexual reproduction). Insects most often use parthenogenesis temporarily to exploit resources when they are abundant.
There are three types of parthenogensis:
- arrhenotoky - males develop from unfertilized eggs, and females develop from fertilized eggs. This is the type of parthenogenetic reproduction seen in bees and wasps.
- thelytoky - females develop from unfertilized eggs. In species that exhibit this form of parthenogenetic reproduction, males are entirely unknown or extremely rare. Some insects, most notably the aphids and gall wasps, alternate between sexual reproduction and thelytoky.
- deuterotoky - both males and females develop from unfertilized eggs.
- Insect Molecular Genetics: An Introduction to Principles and Applications, by Marjorie A. Hoy
- Borror and DeLong's Introduction to the Study of Insects, 7th edition, by Charles A. Triplehorn and Norman F. Johnson
- Parthenogenesis, by Marc Srour, Teaching Biology blog. Accessed January 22, 2013.
- Parthenogenesis, Entomology 601 Lectures, Texas A&M University. Accessed January 22, 2013.