Valid Names Results

Acanthococcus quercus (Comstock, 1881) (Eriococcidae: Acanthococcus)

Nomenclatural History

• Rhizococcus quercus Comstock 1881a: 340. Type data: UNITED STATES: Florida, Fort George, on Gramineae, 27/04/1880, by R.S. Turner. Syntypes, female, Type depository: Washington: United States National Entomological Collection, U.S. National Museum of Natural History, District of Columbia, USA; accepted valid name Illustr.
• Eriococcus quercus (Comstock, 1881); Cockerell 1894: 31. change of combination
• Eriococcus howardi Ehrhorn 1906: 331. Type data: UNITED STATES: California, Santa Clara Co., Calaveras Valley, on Quercus sp., ?/07/1901. Syntypes, female, Type depository: Washington: United States National Entomological Collection, U.S. National Museum of Natural History, District of Columbia, USA; junior synonym (discovered by Ferris1920b, 20). Notes: Five slides of type material in USNM.
• Eriococcus quercus gilensis Cockerell 1909b: 167-168. Type data: UNITED STATES: Arizona, Gila Co., Belleuve, on Quercus toumeyi, 17/07/1908, by D.G. Craig. Syntypes, female, Type depository: Washington: United States National Entomological Collection, U.S. National Museum of Natural History, District of Columbia, USA; junior synonym (discovered by Lindin1931, 114).
• Nidularia quercus (Comstock, 1881); Lindinger 1933a: 116. change of combination
• Acanthococcus quercus (Comstock, 1881); Koteja & Zak-Ogaza 1981: 514. change of combination Notes: Miller & Miller (1992) erroneously cited Acanthococcus quercus as a new combination. The combination was originally put forth by Koteja & Zak-Ogaza (1981). Illustr.

Common Names

• oak eriococcin MillerMi1992
• oak eriococcus Westco1973

Ecological Associates

Hosts:

Families: 2 | Genera: 2

Foes:

Families: 2 | Genera: 2

Geographic Distribution

Keys

• Koszta1996: pp.227 ( Adult (F) ) [Acanthococcus species of Northeastern North America] Key as: Acanthococcus quercus
• Gill1993: pp.157 ( Adult (F) ) [Acanthococcus species of California] Key as: Acanthococcus quercus
• MillerMi1993: pp.7 ( Adult (F) ) [Acanthococcus of the eastern United States] Key as: Acanthococcus quercus
• MillerMi1992: pp.5 ( Adult (F) ) [Acanthococcus species in the western United States] Key as: Acanthococcus quercus
• McDani1964: pp.103 ( Adult (F) ) [Eriococcus species of Texas]
• Ferris1955a: pp.95 ( Adult (F) ) [Eriococcus species of North America]

Remarks

• Systematics: Slide-mounted adult female with: enlarged setae conical, sides slightly concave or straight, apices acute, marginal setae often slightly larger than other setae, abundant over dorsal surface; anal lobes heavily sclerotized, medial margins with teeth; tibia conspicuously longer than tarsus; microtubular ducts with 1 sclerotized area (Miller & Miller, 1992).
• Structure: Adult female is dark reddish-purple with faint yellow stripe on dorsomedial area. Covered dorsally with many short crystalline rods that curve back to the derm. Lateral rods longer than those on medial areas and curve only slightly. Ovisac is white and heavy, encloses 91-146 dark red eggs (Miller & Miller, 1992).
• Biology: This species is bivoltine in the central valley of California and is found on newly formed branches and leaf axils of its host. Rarely feeds on leaves. The species has an eastern form occurring from eastern Texas to Florida and along the east coast to New Jersey and a western form which occurs from western Texas to central California (Miller & Miller, 1992). Eriococcus quercus has two overlapping generations per year with females undergoing three developmental stages, while males have additional prepupal and pupal stages. Eggs begin to hatch in late March in eastern Tennessee. Upon hatching the crawlers migrate to new growth and settle on the underside of the breanches. Most crawlers tend to settle close to one another in a circular fashion around the nodes and leaf buds or in damaged areas on the branch. Males tend to settle around a cluster of females or aggregate in separate groups apart from the females. Once settled, individuals begin to produce a whitish felt-like covering (test). In the second generation, eggs begin to hatch in mid-July through early-August. Adult females are the dominant stage from mid-September through the winter months. The adult males begin emerging in mid-September.OOverwintering adult females may lay eggs during the winter months that are protected by the test until hatching. (Lambdin, et al., 2008)
• Economic Importance: This species is considered a pest of oak in some parts of Maryland (Davidson, personal communication, April 6, 1998), and in Tennessee (Lambdin, personal communication, April 6, 1998).
• General Remarks: Kosztarab (1996) indicates that this species probably exists in eastern Canada, but since it is known no further north than New Jersey, we doubt that it occurs in Canada. Detailed descriptions and illustrations given by Ferris (1955a) and Miller & Miller (1992).

Illustrations

Citations