View source for Gall wasp

{{Short description|Family of wasps}}
{{Automatic taxobox
| name            = Gall wasp
| image           = Gall Wasp - Cynipidae family, Leesylvania State Park, Woodbridge, Virginia.jpg
| image_caption   = 
| display_parents = 3
| taxon           = Cynipidae
| authority       = Latreille, 1802
| diversity_link  = List of Cynipidae genera
| diversity       = at least 80 genera
}}
[[File:Diastrophus nebulosus. adults. gall.jpg|thumb|''Diastrophus nebulosus'' on a raspberry gall]]

'''Gall wasps''', also [[wikt:gallfly#Usage notes|traditionally called]] '''gallflies''', are [[hymenoptera]]ns of the family '''Cynipidae''' in the wasp superfamily [[Cynipoidea]]. Their common name comes from the [[gall]]s they induce on [[plant]]s for larval development. About 1,300 species of this generally very small creature ({{Convert|1–8|mm|disp=or|frac=32}}) are known worldwide,<ref name="Abe Melika Stone 2007">{{Cite Q|Q56853717}}</ref> with about 360 species of 36 different genera in Europe and some 800 species in North America.

== Features ==

Like all [[Apocrita]], gall wasps have a distinctive body shape, the so-called [[Petiole (insect anatomy)|wasp waist]]. The first abdominal [[tergum]] (the [[propodeum]]) is conjoined with the [[Thorax (insect anatomy)|thorax]], while the second abdominal segment forms a sort of shaft, the [[Petiole (insect anatomy)|petiole]]. The petiole connects with the [[gaster (insect anatomy)|gaster]], which is the functional [[abdomen]] in apocritan wasps, starting with the third abdominal segment proper. Together, the petiole and the gaster form the [[metasoma]], while the thorax and the [[propodeum]] make up the [[mesosoma]].

The antennae are straight and consist of two or three segments. In many varieties, the backside of the mesosoma appears longitudinally banded. The wings are typically simply structured. The female's egg-depositing [[ovipositor]] is often seen protruding from the tip of the metasoma.

== Reproduction and development ==

The reproduction of gall wasps is usually partly [[parthenogenesis]], in which a male is completely unnecessary, and partly two-sex propagation.<ref name="Stone 2002">[http://www.annualreviews.org/doi/pdf/10.1146/annurev.ento.47.091201.145247 The population biology of oak gall wasps (Hymenoptera: Cynipidae)] Stone et al. (2002) Annual Review of Entomology Vol. 47: 633-668</ref> Most species have [[alternation of generations|alternating generations]], with one two-sex generation and one parthenogenic generation annually, whereas some species produce very few males and reproduce only by parthenogenesis,<ref name="Stone 2002"/> possibly because of infection of the females' [[gamete]]s by [[Endosymbiont|endosymbiotic]] ''[[Wolbachia]]'' bacteria.<ref name="Schilthuizen Stouthamer 1998">{{Cite Q|Q56609382}}</ref> The various generations differentiate both in their appearance and in the form of the [[gall|plant galls]] they induce.

The [[larvae]] of most gall wasps develop in characteristic plant galls they induce themselves, but many species are instead [[inquiline]]s of other gall wasps, such as those of the genus ''[[Synergus]].''

The plant galls mostly develop directly after the female insect lays the eggs. The inducement for the gall formation is largely unknown; discussion speculates as to chemical, mechanical, and viral triggers. The hatching larvae nourish themselves with the nutritive tissue of the galls, in which they are otherwise well-protected from external environmental effects. The host plants, and the size and shape of the galls are specific to the majority of gall wasps, with about 70% of the known species parasitizing various types of [[oak]], inducing [[Oak apple|oak galls]]. Galls can be found on nearly all parts of such trees, including the leaves, buds, branches, and roots. Other species of gall wasps live in [[eucalyptus]], [[maple]], and many herbs. Species determination is usually much easier through observation of the galls produced rather than of the insect itself.

== Parasitism ==

A [[gall]] protects the developing gall wasp for the most vulnerable stage of its life cycle, but many other wasps have found a way to penetrate this defence and parasitise the gall and/or larva(e) within. Some of these [[Inquiline|inquilines]] and [[parasitoids]] use their long, hardened egg-laying tube ([[ovipositor]]) to bore into the gall. These parasitoids may, in turn, be preyed upon by other wasps, [[hyperparasitoid]]s.<ref name="Piper 2007">{{cite book |last=Piper |first=Ross |author-link=Ross Piper |year=2007 |chapter=Galls |title=Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals |url=https://archive.org/details/extraordinaryani0000pipe |url-access=registration |publisher=[[Greenwood Press (publisher)|Greenwood Press]] |isbn=978-0313339226 }}</ref>

== Types ==<!--this needs [[WP:TNT]] rewriting and citing, it doesn't cover the subject at all-->

Most species of gall wasps live as gall-formers on oaks. One of the best-known is the common oak gall wasp (''[[Cynips quercusfolii]]''), which induces characteristic, 2-cm in diameter, spherical galls on the undersides of oak leaves.

<gallery mode="nolines">
File:Andricus foecundatrix Quercus01.jpg|{{center|''[[Andricus fecundatrix]]'' parthenogenetic generation, [[oak artichoke gall]]}}
File:Gallwespe bedient sich Eichel2.jpg|{{center|''[[Andricus quercuscalicis]]'' parthenogenetic generation gall}}
File:Diplolepis Quercus02.jpg|{{center|''[[Andricus quercuscalicis]]'' parthenogenetic generation gall}}
File:Eikengallen op mannelijke bloeiwijze.jpg|{{center|''[[Neuroterus quercusbaccarum]]'' sexual generation gall}}
File:Oak Gall.jpg|{{center|''[[Andricus kollari]]'' parthenogenetic generation, oak marble gall}}
File:Cynips longiventris gall.jpg|{{center|''[[Cynips longiventris]]'' parthenogenetic generation gall}}
File:Oak Gall Wasp.jpeg|{{center|oak gall}}
File:Acorn Plum Gall.jpg|Acorn Plum Gall
File:Acorn Plum Gall, cut in half, with larva.jpg|Acorn Plum Gall, cut in half, with larva
File:Common Spangle gall.JPG|{{center|''[[Neuroterus quercusbaccarum]]'' common spangle gall}}
File:Hopea Ponga 21.JPG|Galls on ''[[Hopea ponga]]'' at [[Peravoor]]
File:Diastrophus nebulosus gall.jpg|Raspberry gall made by ''[[Diastrophus nebulosus]]'', larvae inside gall
</gallery>

These turn reddish in the fall and are commonly known as [[oak apple]]s. Light lentiform galls on the undersides of the same leaves are induced by ''Neuroterus quercusbaccarum''; darker ones with bulging edges are formed by ''Neuroterus numismalis.'' Also striking are the galls of ''Cynips longiventris,'' which likewise can be found on the undersides of leaves, and are recognizable for their spheroidal shape and irregular red streaks. The oak potato gall wasp (''Biorrhiza pallida'') has round galls that grow to about 4&nbsp;cm. These are known colloquially as [[oak potato]]es. The latter type of gall is induced by this type of wasp not on the leaves, but on the roots of the oak. On the buds of young oak twigs, one can often find the hard-shelled galls of ''Andricus kollari'' and ''Andricus quercustozae.''  Galls do not cause significant harm to oak trees.<ref name="Kidd 2012">{{cite web |last=Kidd |first=Russell |title=Tree galls are rarely cause for concern |url=http://msue.anr.msu.edu/news/tree_galls_are_rarely_cause_for_concern |date=September 10, 2012 |publisher=Michigan State University Extension}}</ref>

== Evolution ==
<!--We should have a section on 
=== Fossil history === 
here
-->

=== External phylogeny ===

The external phylogeny of the Cynipidae is based on Peters et al 2017. The Apocrita is within the "Sawflies" which are shown separately for simplicity here.<ref name=Peters>{{Cite journal |last1=Peters |first1=Ralph S. |last2=Krogmann |first2=Lars |last3=Mayer |first3=Christoph |last4=Donath |first4=Alexander |last5=Gunkel |first5=Simon |last6=Meusemann |first6=Karen |last7=Kozlov |first7=Alexey |last8=Podsiadlowski |first8=Lars |last9=Petersen |first9=Malte |title=Evolutionary History of the Hymenoptera |journal=Current Biology |volume=27 |issue=7 |pages=1013–1018 |doi=10.1016/j.cub.2017.01.027 |pmid=28343967 |year=2017 |doi-access=free |bibcode=2017CBio...27.1013P |hdl=2434/801122 |hdl-access=free }}</ref>

{{clade
   |label1=[[Hymenoptera]]
   |1={{clade
      |1=[[Sawfly|Sawflies]] ([[paraphyletic]]) [[File:Hymenoptera Vielfalt Horntail.jpg|55px]]
      |label2=[[Apocrita]]
      |2={{clade
         |label1=[[Parasitoida]]
         |1={{clade
            |1={{clade
               |1=[[Ceraphronoidea]]
               |2=[[Ichneumonoidea]] [[File:Ichneumon wasp - Flickr - gailhampshire (5) (cropped).jpg|70px]]
               }}
            |label2=[[Proctotrupomorpha]]
            |2={{clade
               |label1=[[Cynipoidea]]
               |1={{clade
                  |1='''Cynipidae''' [[File:29 Cynipidae (9690901832) (cropped).jpg|70px]]
                  |2=other families
                  }}
               |2=[[Chalcidoidea]] and other groups [[File:Torymus female (cropped).jpg|70px]]
               }}
            }} 
         |2={{clade
         |1={{clade
            |1=[[Evanioidea]] [[File:Evania appendigaster (cropped).jpg|90px]]
            |2=[[Stephanoidea]]
            }}
         |2={{clade
            |1=[[Trigonaloidea]]
            |2=[[Aculeata]] (stinging wasps, bees, ants) [[File:AD2009Sep09 Vespula germanica 03.jpg|70px]]
            }}
         }}
      }}
   }}
}}

=== Internal phylogeny ===

The internal phylogeny of gall wasps in the cladogram is based on the molecular phylogenetic analysis of Hearn et al. 2023.<ref name="Hearn Gobbo Nieves-Aldrey 2023"/>

{{clade
|label1='''Cynipidae'''
|1={{clade
    |1={{clade
        |1=[[Eschatocerini]]
        |2={{clade
            |1={{clade
                |1=[[Phanacidini]]
                |2=[[Aulacideini]]
                 }}
            |2={{clade
                |1={{clade
                    |1=[[Qwaqwaiini]]
                    |2=[[Synergini]] ([[inquiline]] gall wasps)
                    }}
                |2={{clade
                    |1=[[Diastrophini]]
                    |2={{clade
                        |1={{clade
                            |1=[[Ceroptresini]] ([[inquiline]] oak gall wasps)
                            |2=[[Aylacini]]
                            }}
                        |2={{clade
                            |1=[[Cynipini]] (oak gall wasps) [[File:Cynips sp beentree.jpg|70px]]
                            }}
                        }}
                    }}
                }}
            }}
        }}
    }}
}}

=== Taxonomy ===

{{further|List of Cynipidae genera}}

The Cynipidae contains two subfamilies, one extinct and one extant:

* [[Cynipinae]]
* [[Hodiernocynipinae]]†

The Cynipinae consists of nine tribes:<ref name="Hearn Gobbo Nieves-Aldrey 2023">{{Cite Q|Q123440111}}</ref>

* [[Aulacideini]] <small>Nieves-Aldrey, Nylander & Ronquist, 2015.</small>
* [[Aylacini]] <small>Ashmead, 1903.</small>
* [[Ceroptresini]] <small>Nieves-Aldrey, Nylander & Ronquist, 2015.</small>
* [[Cynipini]] <small>Billberg, 1820.</small>
* [[Diastrophini]] <small>Nieves-Aldrey, Nylander & Ronquist, 2015.</small>
* [[Eschatocerini]] <small>Ashmead, 1903.</small>
* [[Phanacidini]] <small>Nieves-Aldrey, Nylander & Ronquist, 2015.</small>
* [[Qwaqwaiini]] <small>Liljeblad, Nieves-Aldrey & Melika, 2011.</small>
* [[Synergini]] <small>Ashmead, 1896.</small>

== In human culture ==

* The galls of several species, especially Mediterranean variants, were once used as tanning agents.
* Before his work in [[human sexuality]], [[Alfred Kinsey]] was known for his study of gall wasps.<ref name="Yudell 1999">{{cite journal |last=Yudell |first=Michael |title=Kinsey's Other Report |url=http://findarticles.com/p/articles/mi_m1134/is_6_108/ai_55127889 |journal=Natural History |issn=0028-0712 |date=July 1, 1999 |volume=108 |issue=6}}</ref>
* Galls formed on oak trees are one of the main ingredients in [[iron gall ink]].

== See also ==

* [[Oak apple]]
* [[Oak marble gall]]
* [[Knopper gall]]
* [[Neurotus quercus-baccarum|Common spangle gall]]
* [[Neuroterus numismalis|Silk button gall]]

== References ==

{{reflist}}

== Further reading ==

* {{cite book |last1=Gauld |first1=I. D. |last2=Bolton |first2=B. |year=1988 |title=The Hymenoptera |location=Oxford |publisher=Oxford University Press |isbn=978-0-19-858521-3 |ref=none}}
* {{cite book |last1=Honomichl |first1=K. |last2=Bellmann |first2=H. |year=1994 |title=Biologie und Ökologie der Insekten |location=Stuttgart |publisher=Gustav Fischer |isbn=978-3-437-25020-0 |language=de |ref=none}}
* {{cite book |last=Liljeblad |first=J. |year=2002 |title=Phylogeny and Evolution of Gall Wasps ({{lang|la|Hymenoptera: Cynipidae}}) |publisher=Department of Zoology, Stockholm University. 1–176. Doctoral thesis |isbn=978-91-7265-494-5 |ref=none}}

== External links ==

* {{Commons category-inline|Cynipidae}}
* [http://entomology.ifas.ufl.edu/creatures/trees/Callirhytis_gall_wasps.htm ''Andricus quercusclavigera'' and ''A. quercuscornigera''] on the [[University of Florida|UF]] / [[Institute of Food and Agricultural Sciences|IFAS]] Featured Creatures Web site
* [[Species:Cynipidae|Wikispecies entry]]
* [http://bugguide.net/node/view/14878/bgpage Family Cynipidae] at [http://bugguide.net/ BugGuide]

{{Hymenoptera|2}}

{{Taxonbar|from=Q640774}}

[[Category:Cynipidae| ]]
[[Category:Gall-inducing insects]]
[[Category:Asexual reproduction in animals]]