![Diastrophus nebulosus](https://upload.wikimedia.org/wikipedia/commons/7/70/Diastrophus_nebulosus._adults._gall.jpg)
Gall wasps, also incorrectly called gallflies, are
hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...
ns of the family Cynipidae in the wasp superfamily
Cynipoidea
The Cynipoidea are a moderate-sized hymenopteran superfamily that presently includes five modern families and three extinct families, though others have been recognized in the past. The most familiar members of the group are phytophagous, especia ...
. Their common name comes from the
gall
Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...
s they induce on
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
s for larval development. About 1,300 species of this generally very small creature (1–8 mm) are known worldwide,
with about 360 species of 36 different genera in Europe and some 800 species in North America.
Features
Like all
Apocrita
Apocrita is a suborder of insects in the order Hymenoptera. It includes wasps, bees, and ants, and consists of many families. It contains the most advanced hymenopterans and is distinguished from Symphyta by the narrow "waist" ( petiole) formed ...
, gall wasps have a distinctive body shape, the so-called
wasp waist
Wasp waist is a women's fashion silhouette, produced by a style of corset and girdle, that has experienced various periods of popularity in the 19th and 20th centuries. Its primary feature is the abrupt transition from a natural-width rib cag ...
. The first abdominal
tergum
A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the Anatomical terms of location#Dorsal and ventral, dorsal ('upper') portion of an arthropod segment other than the head. The Anatomical terms of location#Ante ...
(the
propodeum
The propodeum or propodium is the first abdominal segment in Apocrita Hymenoptera (wasps, bees and ants). It is fused with the thorax to form the mesosoma. It is a single large sclerite, not subdivided, and bears a pair of spiracles. It is strongl ...
) is conjoined with the
thorax
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...
, while the second abdominal segment forms a sort of shaft, the
petiole. The petiole connects with the
gaster, which is the functional
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
in apocritan wasps, starting with the third abdominal segment proper. Together, the petiole and the gaster form the
metasoma
The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and circula ...
, while the thorax and the
propodeum
The propodeum or propodium is the first abdominal segment in Apocrita Hymenoptera (wasps, bees and ants). It is fused with the thorax to form the mesosoma. It is a single large sclerite, not subdivided, and bears a pair of spiracles. It is strongl ...
make up the
mesosoma
The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings.
In hymenopterans of t ...
.
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
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
is often seen protruding from the tip of the metasoma.
Reproduction and development
The reproduction of gall wasps is usually partly
parthenogenesis
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...
, in which a male is completely unnecessary, and partly two-sex propagation.
[The population biology of oak gall wasps (Hymenoptera: Cynipidae)](_blank)
Stone et al. (2002) Annual Review of Entomology Vol. 47: 633-668 Most species have
alternating generations, with one two-sex generation and one parthenogenic generation annually, whereas some species produce very few males and reproduce only by parthenogenesis,
possibly because of infection of the females'
gametes
A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...
by
endosymbiotic
An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship.
(The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within" ...
''
Wolbachia
''Wolbachia'' is a genus of intracellular bacteria that infects mainly arthropod species, including a high proportion of insects, and also some nematodes. It is one of the most common parasitic microbes, and is possibly the most common reproduct ...
'' bacteria. The various generations differentiate both in their appearance and in the form of the
plant galls they induce.
The larvae of most gall wasps develop in characteristic plant galls they induce themselves, but many species are instead
inquiline
In zoology, an inquiline (from Latin ''inquilinus'', "lodger" or "tenant") is an animal that lives commensally in the nest, burrow, or dwelling place of an animal of another species. For example, some organisms such as insects may live in the h ...
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 tree
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably '' ...
s. 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 trees
''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...
,
rose bushes
A rose is either a woody perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred species and tens of thousands of cultivars. They form a group of plants that can be ...
or
maple trees
''Acer'' () is a genus of trees and shrubs commonly known as maples. The genus is placed in the family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated since http ...
, as well as many herbs. Species determination is usually much easier through observation of the galls produced rather than of the insect itself.
Parasitism
A
gall
Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...
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 larva(e) within. Some of these
parasitoids
In evolutionary ecology, a parasitoid is an organism that lives in close association with its host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionary strategies within parasi ...
use their long, hardened egg-laying tube (
ovipositor
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
) to bore into the gall and lay an egg on the helpless gall maker. A
bedeguar or robin's pincushions gall, collected before the autumn and kept cool, may result in at least one species of parasitoid emerging instead of the gall maker. These wasps, such as ''
Eurytoma
''Eurytoma'' is a genus of parasitoid chalcid wasps in the family Eurytomidae. There are at least 620 described species in ''Eurytoma''.
File:Eurytoma gigantea.jpg, ''E. gigantea'' larva
File:Eurytoma male.jpg, ''Eurytoma'' sp. adult male
File ...
rosae'', are beautiful, metallic insects with long ovipositors. These parasitoids may, in turn, be preyed upon by other wasps,
hyperparasitoid
A hyperparasite, also known as a metaparasite, is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two o ...
s.
Types
Most species of gall wasps live as gall-formers on oaks. One of the most well-known is the common oak gall wasp (''
Cynips quercusfolii
''Cynips quercusfolii'' is a gall wasp species in the genus ''Cynips''. The species is important for the production of commercial nutgall formed on ''Quercus lusitanica
''Quercus lusitanica'', commonly known as gall oak, Lusitanian oak, or dye ...
''), which induces characteristic, 2-cm in diameter, spherical galls on the undersides of oak leaves.
Image:Diplolepis-rosae.jpg,
Image:Andricus foecundatrix Quercus01.jpg,
Image:Gallwespe bedient sich Eichel2.jpg,
Image:Diplolepis Quercus02.jpg,
Image:Eikengallen op mannelijke bloeiwijze.jpg,
Image:Oak Gall.jpg,
Image:Cynips longiventris gall.jpg,
Image:Oak Gall Wasp.jpeg,
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, Common Spangle gall
File:Hopea Ponga 21.JPG, Galls on '' Hopea ponga'' at Peravoor
Peravoor is a small town and Grama Panchayat in Kannur district of Kerala state in India. It is located east of Kannur and north east of Thalassery. And Iritty, the nearest municipality is north of Peravoor. Peravoor is situated in the Wes ...
File:Diastrophus nebulosus gall.jpg, Raspberry gall made by ''Diastrophus nebulosus
''Diastrophus'' is a genus of gall wasps in the family Cynipidae. There are at least eight described species in ''Diastrophus''.
Species
These eight species belong to the genus ''Diastrophus'':
* ''Diastrophus colombianus'' Nieves-Aldrey, 2013 ...
'', larvae inside gall
These turn reddish in the fall and are commonly known as
oak apple
Oak apple or oak gall is the common name for a large, round, vaguely apple-like gall commonly found on many species of oak. Oak apples range in size from in diameter and are caused by chemicals injected by the larva of certain kinds of gall ...
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 cm. These are known colloquially as
oak potatoes. 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.
The galls of the rose gall wasp (''Diplolepis rosae'') are also distinctive and are known as
bedeguars or robin's pincushions. These are found on the shoots of dog roses and have a length of up to 5 cm with red, long-haired outgrowths. Inside the galls are several chambers, which may be occupied by larvae.
Subfamilies
There are two subfamilies, one extinct and one extant:
*
Cynipinae
Cynipinae is a subfamily of Gall wasp, gall wasps (Cynipidae). Many of the approximately 1,500 described species cause Gall, galls on Oak, oaks, but some induce galls on other plant species or are Inquiline, inquilines of the gall-inducing specie ...
*
Hodiernocynipinae†
Tribes
There are twelve tribes:
*
Aulacideini Nieves-Aldrey, Nylander & Ronquist, 2015.
*
Aylacini Ashmead, 1903.
*
Ceroptresini
Ceroptresini is a Tribe (biology), tribe of Cynipini, oak gall wasps in the Family (biology), family Gall wasp, Cynipidae, and includes two Genus, genera: ''Ceroptres'' and ''Buffingtonella''. All but one of the 22 species currently recognized ar ...
Nieves-Aldrey, Nylander & Ronquist, 2015.
*
Cynipini
Cynipini is a tribe of gall wasps. These insects induce galls in plants of the beech and oak family, Fagaceae. They are known commonly as the oak gall wasps.Melika, G., et al. (2013)A new genus of oak gallwasp, ''Cyclocynips'' Melika, Tang & Sinc ...
Billberg, 1820.
*
Diastrophini Nieves-Aldrey, Nylander & Ronquist, 2015.
*
Diplolepidini Latreille, 1802.
*
Eschatocerini Ashmead, 1903.
*
Paraulacini Nieves-Aldrey & Liljeblad, 2009.
*
Pediaspini Ashmead, 1903.
*
Phanacidini Nieves-Aldrey, Nylander & Ronquist, 2015.
*
Qwaqwaiini Liljeblad, Nieves-Aldrey & Melika, 2011.
*
Synergini
Synergini is a tribe (biology), tribe of gall wasps in the subfamily Cynipinae.
Genera
The following genera are generally accepted within Synergini:
* ''Agastoroxenia''
* ''Lithosaphonecrus''
* ''Saphonecrus''
* ''Rhoophilus''
* ''Synergus ...
Ashmead, 1896.
Genera
*
List of Cynipidae genera
Additional information
* The galls of several species, especially Mediterranean variants, were once used as tanning agents.
* Before his work in
human sexuality
Human sexuality is the way people experience and express themselves sexually. This involves biological, psychological, physical, erotic, emotional, social, or spiritual feelings and behaviors. Because it is a broad term, which has varied ...
,
Alfred Kinsey
Alfred Charles Kinsey (; June 23, 1894 – August 25, 1956) was an American sexologist, biologist, and professor of entomology and zoology who, in 1947, founded the Institute for Sex Research at Indiana University, now known as the Kinsey Instit ...
was known for his study of gall wasps.
* Galls formed on oak trees are one of the main ingredients in
iron gall ink
Iron gall ink (also known as common ink, standard ink, oak gall ink or iron gall nut ink) is a purple-black or brown-black ink made from iron salts and tannic acids from vegetable sources. It was the standard ink formulation used in Europe for t ...
.
See also
*
Oak apple
Oak apple or oak gall is the common name for a large, round, vaguely apple-like gall commonly found on many species of oak. Oak apples range in size from in diameter and are caused by chemicals injected by the larva of certain kinds of gall ...
*
Oak marble gall
''Andricus kollari'', also known as the marble gall wasp, is a parthenogenetic species of wasp which causes the formation of marble galls on oak trees. Synonyms for the species include ''Cynips kollari'', ''Andricus quercusgemmae'', ''A. minor'', ...
*
Knopper gall
''Andricus quercuscalicis'' is a gall wasp species inducing knopper galls.
Knopper galls develop as a chemically induced distortion of growing acorns on pedunculate oak (''Quercus robur'' L.) trees, caused by gall wasps, which lay eggs in buds w ...
*
Rose bedeguar gall
''Diplolepis rosae'' is a gall wasp which causes a gall known as the rose bedeguar gall, Robin's pincushion, mossy rose gall, or simply moss gall.Darlington, Arnold (1975) ''The Pocket Encyclopaedia of Plant Galls in Colour.'' Pub. Blandford Pres ...
*
Common spangle gall
*
Silk button gall
References
* This article is based on a translation of the
corresponding article from the German Wikipedia.
Further reading
*
*
*
External links
*
''Andricus quercusclavigera'' and ''A. quercuscornigera''on the
UF /
IFAS Featured Creatures Web site
*
Wikispecies entry
Family Cynipidaea
BugGuide
{{Taxonbar, from=Q640774
Gall-inducing insects
Asexual reproduction in animals