Andricus quercuscalifornicus

Andricus quercuscalifornicus
	Andricus quercuscalifornicus galls
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Cynipidae
Genus:	Andricus
Species:	A. quercuscalifornicus
Binomial name
	Andricus quercuscalifornicus; (Bassett, 1881)
Synonyms
	Cynips Q. californicaBassett, 1881;

Last updated April 03, 2024

Andricus quercuscalifornicus (occasionally Andricus californicus), or the California gall wasp, is a small wasp species that induces oak apple galls on white oaks, primarily the valley oak ( Quercus lobata ) but also other species such as Quercus berberidifolia . The California gall wasp is considered an ecosystem engineer, capable of manipulating the growth of galls for their own development. It is found from Washington, Oregon, and California to northern regions of Mexico. Often multiple wasps in different life stages occupy the same gall. The induced galls help establish complex insect communities, promoting the diversification in niche differentiation. Furthermore, the adaptive value of these galls could be attributed their ecological benefits such as nutrition, provision of microenvironment, and enemy avoidance.

Description

The adult wasps are small, stout and brown, about 5 mm long with clear wings nearly twice the length of the body. The antennae are filiform and about the same length as the legs.^[3] Despite their size they are one of the largest species of cynipid wasps.

The gall itself is a typical oak apple gall in appearance, roughly spherical and varies from greenish to reddish or orange depending on host, age and environmental conditions. The galls range in size from a 2–14 cm across and often contain multiple larvae as well as parasites and other species that form a mutual relationship by feeding off the galls themselves. The outer galls are hard in texture and are not easy to penetrate.

Habitat

Andricus quercuscalifornicus can induce and inhabit the galls of a variety of oak species, but they are primarily found in the galls of the Valley Oak. Due to this, they are usually found in areas such as riparian forests, open foothill woodlands, valley savannas, plant groves, and suburban areas. The wasps typically induce galls on the twigs of the Valley Oak, but the inter-tree distribution of these galls can be influenced by a multitude of factors including shoot vigor and the genotype of each tree.^[2]

Life cycle

Andricus quercuscalifornicus is believed to reproduce strictly by parthenogenesis, and no male specimens have ever been recovered.^[4] According to phylogenetic studies, several species of the genus Andricus have cryptic sexual generations.^[5] The adult female lays eggs in the cambium layer of oak twigs during the fall using her ovipositor.^[4] More vigorous twigs will have more galls. The eggs overwinter on the twig, and then hatch in the spring, usually in early April. The resulting larvae induce galls immediately, where they can seem to balloon almost overnight onto the tree. This is the point where most of the parasitoids enter the gall, while it is still soft and small enough for their ovipositor to reach the larvae.^[2] After anywhere from a few weeks to two months,^[4] the gall stops growing and begins to desiccate, turning tan or brown. The larvae pupate and then bore their way out of the gall in late summer or early fall and fly off to lay eggs in other trees. A few larvae overwinter inside the gall and don't emerge until the following fall. The reason for this is unknown.^[6]

These wasps form an important role in the ecosystem, with more than 20 known species that are parasitoids, inquilines, and hyperparasites that live on its life cycle, while the galls form a persistent shelter for various forms of fungi as well as many other insects. Several birds are also known to feed from the galls and their inhabitants.

Life history of the oak gallwasps

Andricus quercuscalifornicus is a parasitic species of gallwasp (Hymenoptera, Cynipidae, Cynipini). The cynipid gall-inducer induces galls of 5-20 cubic centimeters on the twigs of the valley oak (Quercus lobata), an endemic tree in California. Gall growth occurs twice annually, during late spring and mid summer. The abundance and distribution of these galls vary between individual trees, however, there is recorded evidence of trees supporting high densities of galls (50 galls per cubic meter).^[7] The native range of these gall wasps spans from most of California (extremes of southern Washington) to northern Mexico.^[8]

Adaptive value of gall induction

Andricus quercuscalifornicus is an example of an ecosystem engineer because of its ability to induce gall growth.^[9] Several evolutionary hypotheses have been proposed to explain the adaptive nature of plant galls. Many of the benefits of induced galls include nutrition, a refuge from natural enemies, and a consistent environment with controlled abiotic factors. Each of these ecological functions can be described as the "nutrition hypothesis", "enemy-avoidance hypothesis", and "microenvironment hypothesis" respectively. According to recent findings, experimental manipulation of abiotic factors (i.e., relative ambient humidity) indicated that A. quercuscalifornicus larvae modify the internal environments of galls, thereby, supporting the microenvironment hypothesis.^[10] Galls have hygrothermal inertia to slow down the rates of change of abiotic conditions, providing a buffer against desiccation; most apparent in immature galls.^[11] Furthermore, support for the microenvironment hypothesis does not supersede both the natural enemies and nutrition hypotheses. The large galls produced by A. quercuscalifornicus may aid in the protection against other parasitoids however, this can also led to increase predation from avian species.^[12] The moist conditions created in the internal microclimate of galls can also led to increased chance of fungal infection.^[13]

A. quercuscalifornicus insect community

Through modifications of plant tissue, A. quercuscalifornicus is considered a keystone species, facilitating living conditions for a succession of other species. The induced galls are shared with a community of insects including transient occupants, opportunistic foragers, parasitoids, inquilines, and parasitoids of inquilines.^[2] These galls are divided into microscale niches allowing for the coexistence of ecologically similar species that exploit similar feeding strategies. Differences in gall morphology, phenology, and location allows for patterns in differential niche uses to arise. It is possible that niche differentiation may account for the diversity of parasitoid species associated with gall wasps. Gall characteristics can also be predictors of community-level species composition.^[14]

Related Research Articles

Galls or cecidia are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls are often highly organized structures so that the cause of the gall can often be determined without the actual agent being identified. This applies particularly to insect and mite plant galls. The study of plant galls is known as cecidology.

Diplolepis is a genus of approximately fifty species of gall-inducing wasps in the family Diplolepididae. The larvae induce galls on wild roses (Rosa), and rarely on domestic roses.

Gall wasps, also traditionally calledgallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this generally very small creature are known worldwide, with about 360 species of 36 different genera in Europe and some 800 species in North America.

Andricus quercuscalicis is a gall wasp species inducing knopper galls.

<i>Andricus kollari</i> Species of insect

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, A. indigenus and A. circulans.

Andricus foecundatrix is a parthenogenetic gall wasp which lays a single egg within a leaf bud, using its ovipositor, to produce a gall known as an oak artichoke gall, oak hop gall, larch-cone gall or hop strobile The gall develops as a chemically induced distortion of leaf axillary or terminal buds on pedunculate oak or sessile oak trees. The larva lives inside a smaller hard casing inside the artichoke and this is released in autumn. The asexual wasp emerges in spring and lays her eggs in the oak catkins. These develop into small oval galls which produce the sexual generation of wasps. A yew artichoke gall caused by the fly Taxomyia taxi also exists, but is unrelated to the oak-borne species. Previous names or synonyms for the species A. fecundator are A. fecundatrix, A. pilosus, A. foecundatrix, A. gemmarum, A. gemmae, A. gemmaequercus, A. gemmaecinaraeformis and A. quercusgemmae.

The common spangle gall on the underside of leaves and the currant gall on the male catkins or occasionally the leaves, develop as chemically induced distortions on pedunculate oak, or sessile oak trees, caused by the cynipid wasp Neuroterus quercusbaccarum which has both agamic and bisexual generations.

Andricus grossulariae is a gall wasp species inducing agamic acorn cup galls on oak tree acorn cups and sexual phase galls on catkins. Synonyms include Andricus fructuum, Andricus gemellus, Andricus intermedius, Andricus mayri and Cynips panteli.

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. It is the largest cynipid tribe, with about 936 to 1000 recognized species, most of which are associated with oaks. The tribe is mainly native to the Holarctic.

Andricus aries is a species of gall-forming wasps, in the genus Andricus. The species was named by the French entomologist Joseph-Étienne Giraud, in 1859. It is commonly found in eastern Europe and during the 21st century has spread to western Europe.

Diplolepis mayri is a gall inducing insect causing galls on wild roses in the Western Palaearctic. Diploleis mayri is less frequent on rose shrubs than D. rosae.

Feron kingi, the red cone gall wasp, is a species of gall wasp in the family Cynipidae.

Andricus mukaigawae is a species of gall wasp native to southeastern Asia. It creates galls on the buds and leaves of oak trees. The galls are sometimes used by other gall wasps unable to create galls of their own, with both species sharing the gall.

Andricus dimorphus, also called the clustered midrib gall wasp, is a species of oak gall wasp in the family Cynipidae. Galls in which the larvae live and feed are formed in clusters along the midrib on the underside of oak leaves.

Synergus japonicus is a species of gall wasp in the family Cynipidae. Whereas most gall wasps create the galls in which they live, Synergus japonicus is an inquiline species, living in the gall created by another species of wasp. It is native to Japan, China and Russia.

Andricus quercuspetiolicola, also called the oak petiole gall wasp, is a species of oak gall wasp in the family Cynipidae. Galls in which the larvae live and feed are formed along the midrib or petiole of white oak leaves.

Disholcaspis quercusmamma, the oak rough bulletgall wasp, is a species of gall wasp in the family Cynipidae. The quercus in its name is the genus name for oak, while "mamma" is Latin for "breast", presumably a reference to the "nipple" on the gall.

Andricus quercusstrobilanus, the lobed oak gall wasp, is a species of gall wasp in the family Cynipidae, found in North America. The quercus in its specific name is the genus name for oak, while "strobilus" is derived from the Greek strobilo which means "cone", a reference to the cone shape of the gall; thus the gall is sometimes called pine cone oak gall.

Phylloteras volutellae, the conical oak gall wasp, is a species of gall wasp , tribe Cynipini , found in North America.

Druon fullawayi, also known as the yellow wig gall wasp, is a species of gall wasp in the family Cynipidae. It was previously placed in the genus Andricus. William Beutenmüller described the female adult wasps as 1.5-2.25 mm long, black with brown mouth parts and brown legs. The galls of D. fullawayi are tan or yellow, woolly, and measure 5-8 mm in diameter. Each gall holds a single chamber for larvae. They are found in California on oak trees, especially Quercus lobata.

References

↑ Bassett, H. F. (1881). "New Species of Cynipidae". The Canadian Entomologist. 13 (3): 51–53. doi:10.4039/Ent1351-3. S2CID 84730995.
1 2 3 4 Joseph, Maxwell; Gentles, Pearse (1 December 2010). "The parasitoid community of Andricus quercuscalifornicus and its association with gall size, phenology, and location". Biodiversity and Conservation. 20: 203–216. doi: 10.1007/s10531-010-9956-0 .
↑ "Gall Wasp Andricus quercuscalifornicus". Natural History of Orange County, California and nearby places. Retrieved 27 January 2015.
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↑ Stone, Graham N.; Atkinson, Rachel J.; Rokas, Antonis; Aldrey, José-Luis Nieves; Melika, George; Ács, Zoltan; Csóka, György; Hayward, Alexander; Bailey, Richard; Buckee, Caroline; McVEAN, Gilean a. T. (2008). "Evidence for widespread cryptic sexual generations in apparently purely asexual Andricus gallwasps". Molecular Ecology. 17 (2): 652–665. Bibcode:2008MolEc..17..652S. doi:10.1111/j.1365-294X.2007.03573.x. ISSN 1365-294X. PMID 18086197. S2CID 9851440.
↑ Russo, Ronald (2006). Field Guide to Plant Galls of California and other Western States. Berkeley, California: University of California Press. ISBN 978-0-520-24885-4.
↑ Rosenthal, S. S.; Koehler, C. S. (1971-05-17). "Intertree Distributions of Some Cynipid (Hymenoptera) Galls on Quercus lobata". Annals of the Entomological Society of America. 64 (3): 571–574. doi:10.1093/aesa/64.3.571. ISSN 1938-2901.
↑ Russo, Ron (2006). Field guide to plant galls of California and other Western states. University of California Press. ISBN 978-0-520-24885-4.
↑ Wetzel, William C.; Screen, Robyn M.; Li, Ivana; McKenzie, Jennifer; Phillips, Kyle A.; Cruz, Melissa; Zhang, Wenbo; Greene, Austin; Lee, Esther; Singh, Nuray; Tran, Carolyn (2016). "Ecosystem engineering by a gall-forming wasp indirectly suppresses diversity and density of herbivores on oak trees". Ecology. 97 (2): 427–438. Bibcode:2016Ecol...97..427W. doi: 10.1890/15-1347.1 . ISSN 1939-9170. PMID 27145617.
↑ Miller, Donald G.; Ivey, Christopher T.; Shedd, Jackson D. (2009). "Support for the microenvironment hypothesis for adaptive value of gall induction in the California gall wasp, Andricus quercuscalifornicus". Entomologia Experimentalis et Applicata. 132 (2): 126–133. Bibcode:2009EEApp.132..126M. doi:10.1111/j.1570-7458.2009.00880.x. ISSN 1570-7458. S2CID 32277366.
↑ Price, Peter W.; Fernandes, G. Wilson; Waring, Gwendolyn L. (1987-02-01). "Adaptive Nature of Insect Galls". Environmental Entomology. 16 (1): 15–24. doi:10.1093/ee/16.1.15. ISSN 0046-225X.
↑ Abrahamson, Warren G.; Weis, Arthur E. (2020-03-31). Evolutionary Ecology across Three Trophic Levels: Goldenrods, Gallmakers, and Natural Enemies (MPB-29). Princeton University Press. ISBN 978-0-691-20943-2.
↑ Wilson, Dennis (1995-08-01). "Fungal endophytes which invade insect galls: insect pathogens, benign saprophytes, or fungal inquilines?". Oecologia. 103 (2): 255–260. Bibcode:1995Oecol.103..255W. doi:10.1007/BF00329088. ISSN 1432-1939. PMID 28306781. S2CID 23151384.
↑ Bailey, Richard; Schönrogge, Karsten; Cook, James M.; Melika, George; Csóka, György; Thuróczy, Csaba; Stone, Graham N. (2009-08-25). "Host Niches and Defensive Extended Phenotypes Structure Parasitoid Wasp Communities". PLOS Biology. 7 (8): e1000179. doi: 10.1371/journal.pbio.1000179 . ISSN 1545-7885. PMC 2719808 . PMID 19707266.