{{Short description|Family of true bugs}} {{Automatic taxobox | image = Adelges_tsugae_1276001.jpg | image_caption = Hemlock woolly adelgid | fossil_range = {{fossilrange|Eocene|Present}} | taxon = Adelgidae | authority = Schouteden, 1909 | display_parents = 3 | subdivision_ranks = Genera | subdivision = See text }}
The '''Adelgidae'''<ref>Schouteden (1909) ''Rhynchota für 1908. Archiv für Naturgeschichte'' 75(2–2–2): 136–219 [https://www.biodiversitylibrary.org/item/50503#page/562/mode/1up (p. 138 Adelginen)].</ref> are a small family of the Hemiptera closely related to the aphids, and often included in the Aphidoidea with the Phylloxeridae or placed within the superfamily Phylloxeroidea as a sister of the Aphidoidea within the infraorder Aphidomorpha. The family is composed of species associated with pine, spruce, or other conifers, known respectively as "pine aphids" or "spruce aphids". This family includes the former family Chermesidae, or "Chermidae", the name of which was declared invalid by the ICZN in 1955.<ref>insects being called "chermes" sometimes. Another name that was common was "dreyfusia" in other locations ([http://www.fs.fed.us/pnw/pubs/pnw_os_rp-18.pdf ''The Balsam Woolly Aphid Problem in Oregon and Washington''], Norman E. Johnson and Kenneth H. Wright, Research paper No. 18, United States Forest Service, United States Department of Agriculture, April, 1957).</ref> There is still considerable debate as to the number of genera within the family, and the classification is still unstable and inconsistent among competing authors.<ref>[http://www.na.fs.fed.us/fhp/hwa/pub/2005_proceedings/wallace.pdf ''A Historical Review of Adelgid Nomenclature''] {{webarchive |url=https://web.archive.org/web/20071025222634/http://www.na.fs.fed.us/fhp/hwa/pub/2005_proceedings/wallace.pdf |date=October 25, 2007 }}, Matthew S. Wallace, Third Symposium on Woolly Hemlock Adelgids</ref>
There are about fifty species of adelgids known. All of them are native to the northern hemisphere, although some have been introduced to the southern hemisphere as invasive species.<ref>{{cite web|title=Hemlock Woolly Adelgid|url=http://dontmovefirewood.org/gallery-of-pests/hemlock-woolly-adelgid.html|work=Gallery of Pests|publisher=Don't Move Firewood|access-date=20 October 2011}}</ref><ref>{{cite web|title=Balsam Woolly Adelgid|url=http://dontmovefirewood.org/gallery-of-pests/balsam-woolly-adelgid.html|work=Gallery of Pests|publisher=Don't Move Firewood|access-date=20 October 2011}}</ref> Unlike aphids, the adelgids have no tail-like cauda and no cornicles.<ref name=mcgavin>''Bugs of the World'', George C. McGumo, [http://factsonfile.com Facts on File] {{webarchive|url=https://web.archive.org/web/20071014023840/http://www.factsonfile.com/ |date=2007-10-14 }}, 1993, {{ISBN|0-8160-2737-4}}</ref>
Adelgids only lay eggs, and never give birth to live nymphs as aphids do. Adelgids are covered with dense woolly wax. A complete adelgid life cycle lasts two years.<ref name=mcgavin/> Adelgid nymphs are known as sistentes, and the overwintering sistentes are called neosistens.<ref>page 724 of [https://books.google.com/books?id=QRoiz58gyVIC&dq=neosistens&pg=PA724 ''Imms' General Textbook of Entomology''], Tenth Edition, volume 2, Augustus Daniel Imms, Richard Gareth Davies, Owain Westmacott Richards, Springer, 1977, {{ISBN|0-412-15220-7}}</ref>
Rain can kill adelgids by dislodging eggs and sistentes from trees.<ref>[http://www.fs.fed.us/pnw/pubs/pnw_os_rp-18.pdf ''The Balsam Woolly Aphid Problem in Oregon and Washington''], Norman E. Johnson and Kenneth H. Wright, Research paper No. 18, United States Forest Service, United States Department of Agriculture, April, 1957</ref> thumb|right|224px|{{center|Balsam woolly adelgid}} [[File:Adelges abietis. galls.jpg|thumb|Galls of ''Adelges abietis'' (Pineapple gall adelgid) on fir (''Abies'')]]
==Genera== * ''Adelges'' <small>Vallot, 1836</small> * ''Aphrastasia'' <small>Börner, 1909</small> * ''Cholodkovskya'' <small>Börner, 1909</small> * ''Dreyfusia'' <small>Börner, 1908</small> * ''Eopineus'' <small>Steffan, 1968</small> * ''Gilletteella'' <small>Börner, 1930</small> * ''Pineus'' <small>Shimer, 1869</small> * ''Sacchiphantes'' <small>Curtis, 1844</small>
==See also== *Balsam woolly adelgid *Gall adelgid *Hemlock woolly adelgid *Pineapple gall adelgid
==References== {{Reflist}}
==External links== *{{Wikispecies-inline|Adelgidae}} *{{Commons category-inline}}
{{Hemiptera|2}} {{Taxonbar|from=Q2562960}}
Category:Adelgidae Category:Insect pests of temperate forests Category:Hemiptera families Category:Taxa named by Henri Schouteden