Cockroach

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Blaberus giganteus
A cockroach.
A 40-50 million year-old cockroach in Baltic amber.

The cockroach is an insect of the order Blattaria. There are 4,000 species. About 30 species invade human homes. This is less than 1% of all the cockroach species. Four species are pests.

Evolutionary history and relationships[change | edit source]

The families of Mantodea, Isoptera, and Blattaria are usually combined by entomologists into a larger group called Dictyoptera. Current evidence strongly suggests that termites have evolved directly from true cockroaches, and many authors now consider termites to be in the family of cockroaches.[1][2][3]

Historically, the name Blattaria has been used largely interchangeably with the name Blattodea. Blattodea refers to a larger group that includes fossil groups related to roaches, but not true cockroaches themselves.[4] These earliest cockroach-like fossils ("Blattopterans" or "roachids") are from the Carboniferous period between 354–295 million years ago. However, these fossils differ from modern cockroaches in having long ovipositors and are the ancestors of mantis as well as modern cockroaches. The first fossils of modern cockroaches with internal ovipositors appear in the Lower Cretaceous. A proposed phylogeny of the families is shown in the diagram.[5]

 
Blattaria

Polyphagidae


 

Cryptocercidae


 

Blattidae


 

Blattellidae



Blaberidae






Cockroaches in the broader sense (Blattodea) have existed a very long time. The earliest cockroach fossils are 354–295 million years old. Science student, Cary Easterday, found a giant 300 million year old fossil cockroach 9 cm (4 in) long, in a coal mine in Ohio.[6]

Other[change | edit source]

Most cockroaches are omnivores. They are tough, and hard to kill. A cockroach can live for two weeks without a head.[7][8]

Cockroaches become adults in 3-4 months and can live up to one year. A female German cockroach can produce 8 egg cases in her lifetime and each egg case may contain 30-40 eggs.

References[change | edit source]

  1. "Termites are 'social cockroaches'". BBC News. 13 April 2007. http://news.bbc.co.uk/1/hi/sci/tech/6553219.stm. Retrieved 5 February 2011.
  2. Eggleton P. et al. 2007. Biological Letters, June 7, cited in Science News 171 p318
  3. "Termites are cockroaches after all - Natural History Museum". nhm.ac.uk. 2011 [last update]. http://www.nhm.ac.uk/about-us/news/2007/april/news_11364.html. Retrieved 5 February 2011.
  4. Grimaldi D 1997. A fossil mantis (Insecta: Mantoidea) in Cretaceous amber of New Jersey, with coments on early history of Dictyoptera. American Museum Novitates 3204: 1-11
  5. Maekawa K.; Matsumoto T. (2000-10). "Molecular phylogeny of cockroaches (Blattaria) based on mitochondrial COII gene sequences". Systematic Entomology 25: 511–519. doi:10.1046/j.1365-3113.2000.00128.x.
  6. "News in Science - Mega cockroach - 08/11/2001". www.abc.net.au. http://www.abc.net.au/science/news/stories/s409585.htm. Retrieved 2009-02-21.
  7. "NATURE. Critter Guide. Cockroach. | PBS". pbs.org. 2011 [last update]. http://www.pbs.org/wnet/nature/critters/cockroach.html. Retrieved 5 February 2011.
  8. "Fact or Fiction?: A Cockroach Can Live without Its Head: Scientific American". scientificamerican.com. 2011 [last update]. http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-cockroach-can-live-without-head. Retrieved 6 February 2011.