''Dytiscus'' ("little diver" based on

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''δυτικός'', "able to dive" and the diminutive suffix ''-ίσκος'') is a

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

genus of predaceous diving beetles that usually live in

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

s and

pond A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from ...

s. There are 26 species in this genus distributed in Europe, Asia, North Africa and North and Central America. They are predators that can reduce

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e. ''Dytiscus'' are large water beetles with a robust, rounded shape and they measure long depending on the exact species involved. The largest, '' D. latissimus'', is among the largest species in the family and its size is only matched by certain '' Megadytes''. The tarsi of the males are modified into suckers which are used to grip the female in mating. Females are usually larger than the males and come in two forms, with grooved (sulcate) or smooth elytra. Males only ever have smooth elytra. The adults of most species can fly.

Life history

Adult beetles and their larvae are aquatic but the pupae spend their life in the ground. Females lay eggs inside the tissue of aquatic plants such as reeds. The eggs hatch in about three weeks. The larvae (known as "water tigers") are elongate with a round and flat head and strong mandibles. They are predatory and their mandible have grooves on their inner edge through which they are able to suck the body fluids of their prey. The larvae take air from the surface of the water using hairs at the end of their abdomen. These lead to spiracles into which the air is taken. Once the larvae grow to some size, they move to soil at the edge of water and burrow into a cell and pupate. The adults breathe by going to the surface and upending. They collect air under their

elytra An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...

and are able to breathe this collected air using spiracles hidden under the elytra. In '' Dytiscus marginalis'' and other species the tarsus of the forelegs is modified in males to form a circular sucker. A reduced sucker is also seen in the midleg of the male.

Parasitoids

Eggs of ''Dytiscus'' are sometimes parasitized by wasps of the families

Eulophidae The Eulophidae are a large family of hymenopteran insects, with over 4,300 described species in some 300 genera. The family includes the genus '' Elasmus'', which used to be treated as a separate family, "Elasmidae", and is now treated as a s ...

Mymaridae The Mymaridae, commonly known as fairyflies or fairy wasps, are a family of chalcidoid wasps found in temperate and tropical regions throughout the world. The family contains around 100 genera with 1400 species. Fairyflies are very tiny insects ...

and other Chalcidoidea.

Species

''Dysticus'' contains the following species:Dytiscidae Species List
at Joel Hallan's Biology Catalog. Texas A&M University. Retrieved on 7 May 2012. * '' Dytiscus alaskanus'' J.Balfour-Browne, 1944 * '' Dytiscus avunculus'' C.Heyden, 1862 * '' Dytiscus caraboides''

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

, 1758 * '' Dytiscus carolinus'' Aubé, 1838 * '' Dytiscus circumcinctus'' (Ahrens, 1811) * '' Dytiscus circumflexus'' Fabricius, 1801 * '' Dytiscus cordieri'' Aubé, 1838 * '' Dytiscus dauricus'' Gebler, 1832 * '' Dytiscus delictus'' (Zaitzev, 1906) * '' Dytiscus dimidiatus'' Bergsträsser, 1778 * '' Dytiscus distantus'' Feng, 1936 * '' Dytiscus fasciventris'' Say, 1824 * '' Dytiscus habilis'' Say, 1830 * '' Dytiscus harrisii'' Kirby, 1837 * '' Dytiscus hatchi'' Wallis, 1950 * '' Dytiscus hybridus'' Aubé, 1838 * '' Dytiscus krausei'' H.J.Kolbe, 1931 * '' Dytiscus lapponicus'' Gyllenhal, 1808 * '' Dytiscus latahensis'' Wickham, 1931 * ''

Dytiscus latissimus ''Dytiscus latissimus'' is a species of beetle in family Dytiscidae. Description One of the largest representatives of the predaceous diving beetles of the genus '' Dytiscus'', ''D. latissimus'' can reach a length around . This beetle is similar ...

, 1758 * '' Dytiscus latro'' Sharp, 1882 * '' Dytiscus lavateri'' Heer, 1847 * '' Dytiscus marginalis''

, 1758 * '' Dytiscus marginicollis'' LeConte, 1845 * '' Dytiscus miocenicus'' Lewis & Gundersen, 1987 * '' Dytiscus mutinensis'' Branden, 1885 * '' Dytiscus persicus'' Wehncke, 1876 * '' Dytiscus pisanus'' Laporte, 1835 * '' Dytiscus semisulcatus'' (O.F.Müller, 1776) * '' Dytiscus sharpi'' Wehncke, 1875 * '' Dytiscus sinensis'' Feng, 1935 * '' Dytiscus thianschanicus'' (Gschwendtner, 1923) * '' Dytiscus verticalis'' Say, 1823 * '' Dytiscus zersii'' Sordelli, 1882 Image:DytiscusEgg.jpg, Eggs and egglaying Image:DytiscusLarva.jpg, Larva Image:DytiscusPupa.png, Pupa Image:DytiscusSpiracles.png, Spiracles under the elytra Image:DytiscusMale.png, Male with suckers on fore tarsi Image:DytiscusLifeLyd.png, Life history

References

External links

* {{Taxonbar, from=Q1138850 Dytiscidae genera