Notonecta maculata
{{Short description|Species of true bug}}
{{Speciesbox
| taxon = Notonecta maculata
| image = Notonecta maculata MHNT.jpg
| image_caption =Notonecta maculata Ventral side
| image2 = Notonecta maculata MHNT dos.jpg
| image2_caption =Notonecta maculata Dorsal side
| authority = Fabricius, 1794
}}
Notonecta maculata is a backswimmer of the family Notonectidae, found in Europe, including the United Kingdom.
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.{{cite web |url=http://www.naturespot.org.uk/species/notonecta-maculata |accessdate=2012-11-22 |publisher=NatureSpot |title=Notonecta maculata}} 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 species found in their habitats. In their juvenile stages, they primarily eat Daphnia magna and zooplankton, and in adult stages they will also include mosquito eggs{{cite journal |last1=Eitam |first1=Avi |first2=Leon |last2=Blaustein |year=2004 |title=Oviposition habitat selection by mosquitoes in response to predator (Notonecta maculata) density |journal=Physiological Entomology |volume=29 |issue=2 |pages=188–191 |doi=10.1111/j.0307-6962.2004.0372.x}} 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, Notonecta maculata will go after larger Daphnia.{{cite journal |last1=Gergs |first1=Andre |first2=Hans Toni |last2=Ratte |year=2009 |title=Predicting functional response and size selectivity of juvenile Notonecta maculata foraging on Daphnia magna |journal=Ecological Modelling |volume=220 |issue=23 |pages=3331–3341 |doi=10.1016/j.ecolmodel.2009.08.012}} The adult stages will also select for larger Daphnia{{cite journal |last1=Scott |first1=Mary Ann |first2=William W. |last2=Murdoch |year=1983 |title=Selective predation by the backswimmer Notonecta |journal=Limnology and Oceanography |volume=28 |issue=2 |pages=352–366 |doi=10.4319/lo.1983.28.2.0352|bibcode=1983LimOc..28..352S |doi-access=free }} and zooplankton.{{cite journal |last1=Blaustein |first1=Leon |year=1998 |title=Influence of the predatory backswimmer, Notonecta maculata on invertebrate community structure |journal=Ecological Entomology |volume=23 |issue=3 |pages=246–252 |doi=10.1046/j.1365-2311.1998.00138.x}}
The amount of light present affects the predation rate of juvenile Notonecta maculata, although this is not based on the time of day.{{cite journal |last1=Gergs |first1=Andre |first2=Nora Isabel |last2=Hoeltzenbein |first3=Hans Toni |last3=Ratte |year=2010 |title=Diurnal and nocturnal functional response of juvenile Notonecta maculata considered as a consequence of shifting predation behaviour |journal=Behavioural Processes |volume=85 |issue=2 |pages=151–156 |doi=10.1016/j.beproc.2010.07.006|pmid=20637269 }} 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{{cite journal |last1=Briers |first1=Robert A. |first2=Philip H. |last2=Warren |year=1999 |title=Competition between the nymphs of two regionally occurring species of Notonecta (Hemiptera: Notonectidae) |journal=Freshwater Biology |volume=42 |issue=1 |pages=11–20 |doi=10.1046/j.1365-2427.1999.00448.x}} within the United Kingdom, but can also be found in storm water retention ponds, lakes, swamps, and rivers, as long as the water they are in is freshwater.{{Cite journal |last1=Foltz |first1=Sarah J. |first2=Stanley I. |last2=Dodson |year=2009 |title=Aquatic hemiptera community structure in stormwater retention ponds: a watershed land cover approach. |journal=Hydrobiologia |volume=621 |issue=1 |pages=49–62 |doi=10.1007/s10750-008-9631-6 |url=https://www.researchgate.net/publication/225634603 |archiveurl=https://web.archive.org/web/20140203134328/http://www.researchgate.net/publication/225634603_Aquatic_Hemiptera_community_structure_in_stormwater_retention_ponds_a_watershed_land_cover_approach/file/79e41510302a823391.pdf |url-status=dead |archivedate=February 3, 2014}} 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.{{cite journal |last1=McCauley |first1=Shannon J. |first2=Locke |last2=Rowe |year=2010 |title=Notonecta exhibit threat-sensitive, predator induced dispersal |journal=Biology Letters |volume=6 |issue=4 |pages=449–452 |doi=10.1098/rsbl.2009.1082 |pmid=20164083|pmc=2936218}}
The Notonecta genus select habitats which enable them to exploit specific foraging strategies.{{cite journal |last1=Bennet |first1=Donald V. |first2=Frederick A. |last2=Streams |year=1986 |title=Effects of vegetation on Notonecta (Hemiptera) distribution in ponds with and without fish |journal=Oikos |volume=46 |issue=1 |pages=62–69 |doi=10.2307/3565381|jstor=3565381 }} These habitats factor in the presence and density of vegetation, water opacity, nature of the substrate, and prey abundance and diversity. Notonecta maculata instars 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.{{cite journal |last1=Briers |first1=Robert A. |last2=Warren |first2=Philip H. |year=2000 |title=Population turnover and habitat dynamics in Notonecta (Hemiptera: Notonectidae) metapopulations |journal=Oecologia |volume=123 |issue=2 |pages=216–222 |doi=10.1007/s004420051008|pmid=28308726 |bibcode=2000Oecol.123..216B |url=http://researchrepository.napier.ac.uk/Output/316738 |url-access=subscription }}
N. irrorata release two kairomones, n-tricosane and n-heneicosane, that repel the oviposition of Culiseta longiareolata mosquitoes in ponds that N. irrorata inhabits.{{cite journal |title=Predator-released hydrocarbons repel oviposition by a mosquito |first1=Alon |last1=Silberbush |first2=Shai |last2=Markman |first3=Efraim |last3=Lewinsohn |first4=Einat |last4=Bar |first5=Joel E. |last5=Cohen |first6=Leon |last6=Blaustein |journal=Ecology Letters |year=2010 |volume=13 |issue=9 |pages=1129–1138 |doi=10.1111/j.1461-0248.2010.01501.x |pmid=20618841 |accessdate=January 25, 2014 |url=http://research.haifa.ac.il/~leon/documents/Silberbush%20et%20al%20Ecology%20Letters%202010.pdf |archiveurl=https://web.archive.org/web/20131013001355/http://research.haifa.ac.il/~leon/documents/Silberbush%20et%20al%20Ecology%20Letters%202010.pdf |url-status=live |archivedate=October 13, 2013}}