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.
Andricus is a genus of oak gall wasps in the family Cynipidae.
Andricus quercuscalifornicus, or the California gall wasp, is a small wasp species that induces oak apple galls on white oaks, primarily the valley oak 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.
Andricus opertus, the fimbriate gall wasp, is a species of wasp in the family Cynipidae whose bisexual generation induces elongate, spiky galls on the leaves of various species of oaks in California, including valley oak and scrub oak. The galls of the bisexual generation form in spring, adults emerge in late spring, and galls persist on trees until the fall. The unisexual generation of this species forms aborted bud galls in the summer and fall.
Feron kingi, the red cone gall wasp, is a species of gall wasp in the family Cynipidae.
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.
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.
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.
Feron crystallinum, also known as the crystalline gall wasp, is a species of gall-forming wasp in the genus Feron. Its galls are pink and covered in hairs that are white, red, or brown. These galls are often massed together in clumps that can cover the underside of leaves. Individual galls are 12-14 mm high, 7 mm across, and have a single chamber for larvae. The unisexual female generation emerges in late winter, and the bisexual generation of males and females emerges in March. They are found in all species of oaks in California.
Feron parmula, also known as the disc gall wasp, is a species of oak gall wasp in the genus Feron. It induces galls in a wide selection of oak species, especially white oaks, and including hybrids. The galls are disc-shaped, up to 3 mm in diameter, and pale with red streaking. Adult females emerge in April. The galls induced by F. parmula superficially resemble the galls of Feron gigas,Andricus viscidus, and newly identified species called the "plate gall wasp" and the "orange-cap gall wasp" by Richard Russo. Galls induced by this wasp have been documented in Oregon and California on the Pacific coast of North America.
Feron gigas, also known as the saucer gall wasp, is a species of gall-forming wasp in the genus Feron. It induces galls on the leaves of scrub oaks, blue oaks, and Engelmann oaks. The galls produced by its all-female generation, which emerges in winter, are 3-4 mm wide, circular with raised edges. They are red, pink, brown, or purple. The larval chamber exists as a raised bump in the gall's center. The bisexual generation produces galls that are brown and cone-shaped.
Feron pattersonae, also known as the plate gall wasp, is a species of oak gall wasp in the genus Feron. Their hosts are among the white oaks grouping of oaks, with blue oak being common.
Feron atrimentum, also known as the striped volcano gall wasp, is a species of gall-forming wasp in the genus Feron. It induces galls on blue oak leaves. Like other oak gall wasps, it has two generations: a bisexual generation, and a parthenogenic female generation. The bisexual generation produces round, 3–4 millimetres (0.12–0.16 in) galls in spring that start as green or pink, and then turn brown. The unisexual generation produces conical, 4–4 millimetres (0.16–0.16 in) galls in summer that are pale with red stripes.
Feron bakkeri, also known as the pinched leaf gall wasp, is a relatively uncommon species of gall-inducing hymenopteran. They produce pink leaf galls on Oregon oaks and scrub oaks. The distribution of this wasp is California and Oregon in North America. It was previously placed in the genus Andricus.
Trichoteras coquilletti, formerly Andricus coquilletti, also known as the little oak-apple gall wasp, is a fairly common species of cynipid wasp that produces galls on oak trees in North America. This wasp oviposits on the underside of the leaves of huckleberry oaks and canyon live oaks. The larval chamber is at the center of the gall, connected to the husk by slender, radiating fibers.
Trichoteras tubifaciens, formerly Andricus tubifaciens, also known as the crystalline tube gall wasp, is an uncommon species of cynipid wasp that produces galls on oak trees in Califoeni and Oregon in North America. This wasp oviposits on the midrib of the underside of the leaves of Oregon oaks. Up to 35 galls have been observed on a single leaf. Cream, yellow, red, and multicolor variants have been documented.
Atrusca brevipennata, formerly Andricus pellucidus, also known as the little oak-apple gall wasp, is a locally common species of cynipid wasp that produces galls on oak trees in North America. The wasp oviposits on shrub live oak and Gambel oak leaves. The larval chamber is at the center of the gall, connected to the husk by slender, radiating fibers. This wasp is most commonly observed in the American Southwest, as far north as Denver. It is visually similar to, and may be confused with, Atrusca bella.
Besbicus maculosus, formerly Andricus maculosus and Cynips maculosa, also known as the pear gall wasp, is an uncommon species of cynipid wasp that induces galls on oak trees on the west coast of North America. The wasp oviposits on leather oak and scrub oak leaves. Fresh galls are green. This wasp has been observed in California.
Burnettweldia conalis, formerly Disholcaspis conalis, the witches' hat gall wasp, is a species of hymenopteran that induces stem galls on Oregon oaks in North America. The conical stem galls look like witches' hats lined up on a stick. The base of the detachable gall appears to grip the stem. Typical galls are 10 to 18 millimeters tall. Young galls are green, aging galls are fuzzy, and old galls are beige. The type species was collected in Sequoia National Park.
Phylloteras cupella, formerly Trigonaspis cupella, also known as the urn gall wasp or the banded urn gall wasp, is a species of cynipid wasp that induces leaf galls on a number of oak species in western North America. Host species include Arizona white, blue, Engelmann, gray, leather, netleaf, scrub, and shrub oaks. In the United States, galls induced by this species of wasp have been documented in California, Arizona, and New Mexico. This wasp is most likely also in Mexico and Canada.
