Fungal-symbiosis
Guides
Anisandrus
Anisandrus is a genus of ambrosia beetles in the subfamily Scolytinae, tribe Xyleborini, comprising approximately 40-41 species distributed primarily across Asia, with some species introduced to Europe and North America. The genus is characterized by a mycangial tuft at the pronotal base used for transporting symbiotic fungi. Several species, including A. maiche and A. dispar, are recognized as economically significant pests of fruit orchards, ornamental trees, and forest ecosystems.
Anisandrus obesus
Anisandrus obesus is an ambrosia beetle native to eastern North America that specializes in boring into the sapwood of Big Tooth Aspen (Populus grandidentata). Females construct characteristic gallery systems consisting of a single entrance tunnel approximately 7 mm deep followed by two lateral tunnels parallel to the wood surface. The species maintains an obligate symbiosis with ambrosia fungi, which larvae consume without expanding parental galleries. Progeny exhibit strongly female-biased sex ratios (approximately 6:1), with only females emerging in spring to disperse and attack new hosts.
Corthylus
ambrosia beetles, timber beetles
Corthylus is a genus of ambrosia beetles in the family Curculionidae containing more than 190 described species. Species in this genus are characterized by their symbiotic relationships with fungi, which they cultivate in galleries bored into wood. Several species are significant forest pests, attacking hardwood trees and causing structural damage through gallery construction and associated fungal infections that lead to wood rot and tree mortality. The genus includes economically important species such as the Columbian timber beetle (C. columbianus) and C. zulmae, which impact timber production and reforestation efforts.
Corthylus columbianus
Columbian timber beetle, chestnut timber worm
Corthylus columbianus is a scolytid beetle (Curculionidae) native to North America. It is a pest of living hardwood trees, particularly attacking the heartwood and phloem of species such as maple, oak, beech, hickory, and elm. The beetle has a complex life cycle with delayed adult emergence and exhibits dynamic population distribution patterns within forest stands, forming shifting epicenters of attack density. It is associated with ambrosia fungi that cause wood staining and degrade timber quality.
Cyclorhipidion pelliculosum
Cyclorhipidion pelliculosum is a species of ambrosia beetle in the weevil family Curculionidae, described by Hulcr & Cognato in 2010. Like other members of its genus, it is likely associated with fungal cultivation in wood, though specific biological details remain poorly documented. The species has been recorded from both North America and Southern Asia.
Euwallacea similis
ambrosia beetle
Euwallacea similis is a small ambrosia beetle (2.2–2.7 mm) native to South and Southeast Asia and Australia, now globally distributed through human trade in timber and wood commodities. It colonizes stressed, cut, or recently dead host trees rather than healthy living trees, distinguishing it from related invasive species like E. fornicatus. The species exhibits haplodiploid sex determination and inbreeding polygyny, with females farming symbiotic Fusarium fungi in wood galleries. First recorded in the Iberian Peninsula in 2025, it is considered a high-risk quarantine pest due to its polyphagous habits and potential to vector pathogenic fungi.
ambrosia-beetleinvasive-specieshaplodiploidfungal-symbiosisforest-pestxyleboriniquarantine-pestwood-boring-beetleglobal-trade-vectorcryptic-species-complexsecondary-borercrepuscularlight-attractedfusarium-symbiontparthenogenesisinbreeding-polygynygenome-sequencedchromosome-fissioniberian-peninsula-introduction2025-range-expansionGnathotrichus
ambrosia beetles
Gnathotrichus is a genus of ambrosia beetles in the family Curculionidae containing at least 40 described species. Species in this genus cultivate fungal symbionts in wood galleries and are primarily associated with coniferous hosts. Several species have been studied for their pheromone-mediated aggregation behavior, with males producing species-specific attractants. The genus includes both native and invasive species, with Gnathotrichus materiarius established in Europe since the 1930s.
Ibaliidae
ibaliid wasps
The Ibaliidae are a small family of parasitoid wasps in the superfamily Cynipoidea, comprising three extant genera (Ibalia, Heteribalia, and Eileenella) with approximately 20 species worldwide. Unlike most cynipoids, which are phytophagous gall-formers, ibaliids are parasitoids of wood-boring sawfly larvae in the family Siricidae. Adults are notably large for cynipoids, reaching up to 30 mm in length, with a distinctive laterally compressed abdomen. The family is sister to the rest of Cynipoidea excluding the small subfamily Austrocynipidae.
Platypodinae
pinhole borers, ambrosia beetles
Platypodinae is a weevil subfamily within Curculionidae commonly known as pinhole borers. The vast majority of species are ambrosia beetles that cultivate symbiotic fungi in tunnels excavated within dead wood, which serves as the sole food source for their larvae. They function as important early decomposers of dead woody plant material, particularly in wet tropical environments. Only two species are known not to engage in fungal cultivation.
Scolytinae
Bark and Ambrosia Beetles, Bark Beetles
Scolytinae is a subfamily of weevils (Curculionidae) comprising approximately 220 genera and 6,000 species commonly known as bark and ambrosia beetles. Members are characterized by their specialized association with woody plants, where they excavate galleries beneath bark for reproduction and larval development. The subfamily includes some of the most economically significant forest pests globally, such as the southern pine beetle (Dendroctonus frontalis) and mountain pine beetle (Dendroctonus ponderosae), which cause billions of dollars in timber losses. Species exhibit diverse feeding strategies: phloem-feeding bark beetles consume living or dying tree tissues, while ambrosia beetles cultivate symbiotic fungi in galleries as a food source.
Siricinae
horntails, wood wasps
Siricinae is a subfamily of wood-boring wasps within Siricidae, commonly known as horntails. Members possess a distinctive elongated, cylindrical body and a prominent spine-like ovipositor at the tip of the abdomen. Females bore into wood to lay eggs, and larvae develop within timber, feeding on fungal symbionts. The subfamily includes the genus *Sirix*, among others.
Tremex columba
pigeon tremex, pigeon horntail
Tremex columba is a large horntail wasp native to North America. Females possess a prominent ovipositor used to drill into dead or dying hardwood trees to deposit eggs. The species has an obligate symbiotic relationship with the wood-rotting fungus Daedalea unicolor, which females introduce during oviposition and which larvae require for development. Larval development takes one to two years, during which they tunnel through fungus-infected wood. The species is not harmful to humans and does not sting.
Treptoplatypus
Treptoplatypus is a genus of ambrosia beetles (pinhole borers) in the family Curculionidae, subfamily Platypodinae. The genus comprises more than 20 described species, including the rare European species T. oxyurus, which forms obligate nutritional symbioses with ambrosia fungi cultivated within wood galleries. Members of this genus are wood-boring insects that colonize dead or dying trees, with some species showing specialized host associations.
Trypodendron scabricolle
Trypodendron scabricolle is a bark beetle in the weevil family Curculionidae, subfamily Scolytinae. It belongs to the tribe Xyleborini, a group of ambrosia beetles that cultivate fungal gardens in wood. The genus Trypodendron comprises small to medium-sized ambrosia beetles that tunnel into the wood of dead or dying trees. This species, like other members of its genus, is associated with fungal symbiosis rather than direct phloem feeding.
Urocerus flavicornis
Yellow-horned Horntail, Yellow-horned Horntail Wasp
Urocerus flavicornis is a large wood-boring wasp in the family Siricidae, commonly known as the yellow-horned horntail. Native to North America, this species develops inside dead or dying hardwood trees. Adults are active primarily in late summer and fall. The species is non-venomous and poses no threat to humans despite its intimidating appearance.
Xiphydria
wood wasps, xiphydriid wood wasps
Xiphydria is a genus of wood wasps in the family Xiphydriidae, distributed across the Holarctic region including Europe, Asia, and North America. Adults are characterized by a distinctive elongated 'neck' formed by the long propleuron, antennae with approximately 20 segments, and mandibles with four teeth. Females oviposit into diseased or dead wood of broadleaf trees and vector symbiotic fungi that decompose wood for larval consumption. The genus is univoltine with one generation per year. While generally of minor economic importance, some species can damage oak and other hardwoods.
Xiphydriidae
wood wasps, swordtail sawflies
Xiphydriidae is a family of approximately 150 species of wood wasps distributed worldwide across North and South America, Europe, Asia, Australia, and other regions. Adults are distinguished by their globose (dome-shaped) heads borne on long, slender necks, with body lengths ranging from 6–21 mm. Larvae are wood borers in dead or dying trees and branches, where they feed on symbiotic fungi rather than wood directly. The family has a fossil record extending to the mid-Cretaceous, with the oldest known fossils from this period.