''Notonecta maculata'' is a backswimmer of the family

Notonectidae Notonectidae is a cosmopolitan family of aquatic insects in the order Hemiptera, commonly called backswimmers because they swim "upside down" (inverted). They are all predators and typically range from in length. They are similar in appearance ...

, found in Europe, including the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

Morphology

''Notonecta maculata'' are small, light brown insects of the order Hemiptera. These animals have a number of dark markings on their wings and body, and have large reddish eyes. Their hind legs are modified to be oar-shaped, to allow them to swim in water. These animals can grow up to 2 centimeters in length in their adult stage. This individual species can be distinguished from other '' Notonecta'' species by their mottled brick-coloured forewings.

Diet

''Notonecta maculata'' are voracious predators, eating many

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

species found in their habitats. In their juvenile stages, they primarily eat ''Daphnia magna'' and

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

, and in adult stages they will also include

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 "lit ...

eggs to their diet, although they will also eat most things that they can find. In their juvenile stages, they select prey based on size - when presented with multiple sizes of

Daphnia ''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resemb ...

, ''Notonecta maculata'' will go after larger ''Daphnia''. The adult stages will also select for larger ''Daphnia'' and zooplankton. The amount of light present affects the predation rate of juvenile ''Notonecta maculata'', although this is not based on the time of day. In the dark, they will detect ''Daphnia'' at shorter distances, so they will go after the largest ''Daphnia'' in their shorter range.

Habitat

''Notonecta maculata'' generally live in small freshwater ponds within the United Kingdom, but can also be found in storm water retention ponds,

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much lar ...

s, swamps, and

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

s, as long as the water they are in is

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...

. Although they can live in a single pond for all of their life, they will use their wings to fly away to a different pond in the presence of vertebrate predators. The ''Notonecta''

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

select habitats which enable them to exploit specific foraging strategies. These habitats factor in the presence and density of vegetation, water opacity, nature of the substrate, and prey abundance and diversity. ''Notonecta maculata''

instars An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

tend to survive better in an environment where these elements are in a relatively simple state, and will not survive as well when these factors in the environment are more complex, although their survival rate in a complex environment increases as it goes through instar stages. ''N. irrorata'' release two

kairomone A kairomone (a coinage using the Greek καιρός ''opportune moment'', paralleling pheromone"kairomone, n.". OED Online. September 2012. Oxford University Press. http://www.oed.com/view/Entry/241005?redirectedFrom=kairomone (accessed 3 Octobe ...

s, ''n''-tricosane and ''n''-heneicosane, that repel the oviposition of ''

Culiseta longiareolata ''Culiseta longiareolata'' is a species of mosquito. Distribution This species can be found in the following countries: *Albania *Botswana *Bulgaria *Cyprus *Djibouti *Egypt *Ethiopia *France *Greece *Hungary *India *Iran *Iraq *Israel *Italy *J ...

'' mosquitoes in ponds that ''N. irrorata'' inhabits.

References

{{Taxonbar, from=Q7063220 Notonecta Hemiptera of Europe Fauna of the United Kingdom Insects described in 1794