Oak
Guides
Synergini
inquiline gall wasps
Synergini is a tribe of inquiline gall wasps in the family Cynipidae. Members have lost the ability to induce their own galls and instead inhabit galls created by other cynipid wasps, primarily those in tribe Cynipini. The tribe includes genera such as Synergus, Saphonecrus, Lithosaphonecrus, and Ufo. Most species are associated with oaks (Quercus) and related Fagaceae. A 2015 taxonomic revision transferred three former Synergini genera to other tribes: Ceroptres to its own tribe Ceroptresini, and Periclistus and Synophromorpha to Diastrophini.
Synergus
inquiline oak gall wasps
Synergus is a genus of inquiline gall wasps in the tribe Synergini (Hymenoptera: Cynipidae). Most species develop within galls induced by other cynipid wasps on oaks (Quercus), though some inhabit galls on chestnuts (Castanea). The genus is distributed worldwide, with notable diversity in the New World and Eastern Palaearctic. One species, S. itoensis, has independently evolved the ability to induce its own galls inside oak acorns, representing a rare transition from inquilinism to gall induction. Species are morphologically grouped by fore wing radial cell structure and mesopleural sculpture.
Syneta simplex
Syneta simplex is a leaf beetle species native to North America. The species comprises two recognized subspecies with distinct elevational and host plant preferences. The nominate subspecies S. s. simplex occurs at lower elevations and feeds on Garry oak (Quercus garryana), while S. s. subalpina inhabits subalpine zones near timberline in Washington and British Columbia and feeds on alpine fir (Abies lasiocarpa). The species belongs to the family Chrysomelidae, a diverse group of herbivorous beetles commonly known as leaf beetles.
Tischeria quercitella
Oak Blotch Miner Moth
Tischeria quercitella is a leaf-mining moth in the family Tischeriidae. Its larvae create distinctive blotch mines on the leaves of oaks (Quercus) and chestnuts (Castanea). The species is documented across eastern North America, with records from Ontario south to Virginia and west to Missouri and Illinois.
Torymus advenus
Torymus advenus is a parasitoid wasp in the family Torymidae, part of a species group characterized by associations with oak galls. The species was described by Osten-Sacken in 1870. Members of the advenus species group are parasitoids of gall-forming insects, particularly cynipid wasps and gall midges on oaks. Direct biological data for T. advenus sensu stricto is limited; most ecological understanding derives from related species in the group.
Typhlocyba quercus
orange-spotted leafhopper
Typhlocyba quercus is a leafhopper species in the family Cicadellidae, commonly known as the orange-spotted leafhopper. It is a phloem-feeding insect primarily associated with oak trees (Quercus species), where it completes its entire life cycle. The species overwinters as eggs deposited in oak twigs, with nymphal development occurring in spring and adults present from mid-summer through fall. Multiple generations occur annually.
Urgleptes querci
Oak Long-horned Beetle
Urgleptes querci is a species of longhorn beetle in the family Cerambycidae, first described by Asa Fitch in 1858. It is a small to medium-sized cerambycid native to eastern North America, where it develops in dead wood of various hardwood trees. The species is highly polyphagous and has been recorded from multiple host plants including oak, pawpaw, and other deciduous trees. Adults are active during the growing season and are likely nocturnal or crepuscular, as is typical for many Lamiinae.
Xestobium
death-watch beetles
Xestobium is a genus of wood-boring beetles in the family Ptinidae, commonly known as death-watch beetles. The genus contains approximately 13 described species, with Xestobium rufovillosum being the most studied due to its economic significance as a pest of structural timbers in historic buildings. These beetles are renowned for the distinctive tapping sound produced by adults, which serves as a mating signal and has inspired their common name. The genus is primarily associated with decayed hardwoods, particularly oak, and has a prolonged life cycle spanning multiple years.
Xylotrechus colonus
rustic borer, rustic borer beetle
A medium-sized longhorn beetle in the tribe Clytini, known for its distinctive black elytra with variable grey bands and a sinuous yellow mark near the base. The species was described by Fabricius in 1775 and is common in eastern North American woodlands. Larvae are wood-borers in oak sapwood, while adults feed on nectar of composite flowers including goldenrod.
Zapatella davisae
black oak gall wasp
Zapatella davisae is a cynipid gall wasp (Hymenoptera: Cynipidae) described in 2016 that has become a significant pest of black oak (Quercus velutina) in the northeastern United States. Larvae develop under bark in late summer, with adults emerging in early spring. The species has undergone notable population outbreaks on Long Island, NY (first documented 1990), Cape Cod and Martha's Vineyard, MA (2008), and more recently in coastal Rhode Island and Nantucket, MA. High parasitism rates by Sycophila species can lead to rapid population collapse, as observed on Long Island in 2016.