''Dytiscus latissimus'' is a species of
beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
in family
Dytiscidae
The Dytiscidae – based on the Greek ''dytikos'' (δυτικός), "able to dive" – are the predaceous diving beetles, a family of water beetles. They occur in virtually any freshwater habitat around the world, but a few species live a ...
.
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 in structure to the better-known and widespread ''
D. marginalis'', but it is clearly larger and especially wider. The species is usually easy to recognize by the extensions on both sides of the shield. The
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 the pronotum are dark brown with yellow sides. The head is black, while the
legs
A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ...
are yellow. The male's wing cases are shiny, while those of the female are finely grooved. This voracious predator hunts a wide variety of prey, including other
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s,
tadpole
A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...
s, and small
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
. Before they dive, they collect air bubbles in their wing cases which go through the spiracles.
Distribution
This species can be found in northern and central European countries. The species is listed on Annex II and Annex IV of the European Union
Habitats Directive
The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The E ...
; the latter gives it strict protection within the EU member countries.
Habitat
It is an aquatic species and it inhabits in dense vegetation, mainly of ''
Carex
''Carex'' is a vast genus of more than 2,000 species of grass-like plants in the family Cyperaceae, commonly known as sedges (or seg, in older books). Other members of the family Cyperaceae are also called sedges, however those of genus ''Carex'' ...
'' and ''
Equisetum
''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds.
''Equisetum'' is a "living fossil", the only living genus of the entire subclass Eq ...
'', at the edges of lakes or in nonflowing waters and deep ponds. They key parameter of the habitat is the abundance of case-making caddis flies, which serve as the primary food for ''D. latissimus'' larvae.
Conservation
The species was extirpated from much of its previous area, including most of Central Europe. The main reason is the rise of intensive use of water bodies for fish production.
There is a successful breeding program for this species in Latvia, which gives hope for potential reintroduction into formerly inhabited areas, should they become habitable for the species in the future.
Gallery
File: Dytiscus latissimus.jpg , Illustration from ''Fauna Germanica: Die Käfer des deutschen Reiches'' (vol. I, pl. 39) (1908)
References
Further reading
BiolibFauna europaea* Anders N. Nilsson, Mogens Holmen
The aquatic Adephaga (Coleoptera) of Fennoscandia and Denmark, vol. 2
External links
Dytiscus latissimus - Distribution Map Wild Denmark
Dytiscidae
Beetles of Europe
Beetles described in 1758
Taxonomy articles created by Polbot
Taxa named by Carl Linnaeus
{{Dytiscidae-stub