Subcortical
Guides
Anisolabididae
Anisolabididae is a family of earwigs (order Dermaptera, suborder Neodermaptera) comprising 38 genera across 13 subfamilies. Members include both cosmopolitan and geographically restricted species, with some showing specialized adaptations for subcortical or coastal habitats. Several genera, particularly Euborellia, are recognized for their predatory behavior and potential as biological control agents of agricultural pests. The family exhibits diverse morphologies ranging from typical earwig body plans to dorsoventrally flattened forms adapted for life under bark.
Apomecynini
Apomecynini is a tribe of small, flightless (apterous) longhorn beetles within the subfamily Lamiinae. Members are commonly associated with leaf litter and subcortical habitats, particularly in the Neotropics. The tribe includes numerous species, many of which remain undescribed due to their cryptic lifestyle and small size.
Aradus lugubris
flat bug
Aradus lugubris is a species of flat bug in the family Aradidae, first described by Fallén in 1807. It is one of the most widely distributed species in its genus, occurring across the Holarctic region in both Europe and North America. The species is known from forest habitats where it lives under the bark of dead trees. Two subspecies are recognized: A. lugubris lugubris and A. lugubris nigricornis.
Brachypsectra fulva
Texas beetle
Brachypsectra fulva, commonly known as the Texas beetle, is a species in the family Brachypsectridae. Adults are rarely observed but are attracted to light and active from May to August. The larvae are predatory, living under bark, in leaf litter, and rock crevices, where they ambush small arthropod prey. The species occurs in the southwestern United States and Mexico.
Chernetidae
Chernetid Pseudoscorpions
Chernetidae is a large family of pseudoscorpions in the order Pseudoscorpiones, containing over 650 described species across 119 genera. Members are small arachnids lacking a tail and stinger, characterized by prominent pincer-like pedipalps. The family was established by Anton Menge in 1855. Many species inhabit subcortical environments beneath tree bark and are frequently documented engaging in phoresy—attaching to insects such as longhorned beetles (Cerambycidae) for dispersal.
Clinidium sculptile
Carved Slope Beetle
Clinidium sculptile is a small ground beetle in the subfamily Rhysodinae, first described by Edward Newman in 1838. It is endemic to the eastern United States, with its range centered on the Appalachian region. The species has been documented in association with pitch pine and tulip tree.
Clinidium valentinei
Clinidium valentinei is a small ground beetle in the family Rhysodidae, described by R.T. Bell in 1970. It is endemic to the Appalachian Mountains of the eastern United States, ranging from northern Alabama to southwestern Pennsylvania. The species measures 5.4–6.4 mm in length. Like other rhysodines, it is adapted to life under bark and in decaying wood.
Cryptarchinae
Cryptarchinae is a subfamily of sap-feeding beetles within the family Nitidulidae. The subfamily contains at least 3 genera—Cryptarcha, Glischrochilus, and Pityophagus—and approximately 17 described species. Members are associated with subcortical habitats and sap flows on trees, particularly conifers. The genus Glischrochilus has been the subject of recent taxonomic revision revealing cryptic species diversity in northern Europe.
Cucujidae
flat bark beetles
The Cucujidae are a family of beetles characterized by strongly flattened bodies adapted for living under bark. The family contains approximately 70 species in five genera, distributed worldwide except Africa and Antarctica. Members are primarily found in subcortical habitats on dead trees, where both larvae and adults are predatory. Some species exhibit remarkable physiological adaptations, including extreme freezing tolerance in arctic populations.
Cucujus
flat bark beetles
Cucujus is a genus of flat bark beetles in the family Cucujidae, containing approximately 25 recognized species distributed across the Holarctic region. Species are dorso-ventrally compressed, brightly colored in red or red-and-black patterns, and range from 6–25 mm in length. The genus is most diverse in Asia, with indigenous species in North America, Europe, and Asia. Several species, notably C. cinnaberinus and C. clavipes, have been subjects of ecological and physiological research due to their conservation status and extreme cold tolerance adaptations.
Digamasellidae
Digamasellidae is a family of mesostigmatid mites containing 11 recognized genera. Members are primarily found in subcortical habitats, including bark beetle galleries and decaying wood. At least some species are nematophagous, feeding on nematodes. The family is distributed across Europe and has been recorded in association with pine bark beetles.
Dinaraea
Dinaraea is a genus of rove beetles in the family Staphylinidae, tribe Athetini, comprising approximately 16 described species. The genus is saproxylic, inhabiting dead wood habitats including subcortical galleries, rotting tree trunks, and polypore fruiting bodies. Larval morphology was first described in 2018 based on two European species, revealing diagnostic characters for the genus and distinct morphological differences between early (L1) and late (L2–3) larval instars.
Dinaraea aequata
Dinaraea aequata is a small rove beetle (2.5–3.7 mm) in the subfamily Aleocharinae, native to Europe and parts of Asia. It is saproxylic, inhabiting subcortical galleries of decaying wood and fungal fruiting bodies. The species was among the first in its genus to have its larval morphology and life history described in detail, including all three instars, prepupa, and pupal cocoon.
Eucinetus
plate-thigh beetles
Eucinetus is a genus of plate-thigh beetles in the family Eucinetidae, first described by Germar in 1818. The genus contains at least four extant species, with numerous additional species described in 2019 from both modern and fossil contexts. Notably, Eucinetus has been identified from mid-Cretaceous amber (~100 million years old), representing a striking case of long-term evolutionary stasis. The genus exhibits morphological conservatism while maintaining a specialized subcortical lifestyle.
Gabrius splendidulus
A predatory rove beetle in the subtribe Philonthina, Gabrius splendidulus occurs primarily in Europe and western Russia, with introduced populations in North America. The species develops in subcortical habitats, specifically within bark beetle galleries. Mature larvae have been re-described using light and scanning electron microscopy, with diagnostic characters established to distinguish them from other Philonthina genera.
Lasconotus vegrandis
Lasconotus vegrandis is a species of cylindrical bark beetle in the family Zopheridae, first described by George Henry Horn in 1885. It belongs to a genus characterized by compact, cylindrical body forms adapted for life under bark. The species has been documented in western North America, with records from British Columbia. Like other members of its family, it is presumed to inhabit dead or decaying wood, though specific ecological details remain poorly documented.
Neoproxius
Neoproxius is a genus of flat bugs (Hemiptera: Aradidae) established by Usinger and Matsuda in 1959. The genus belongs to the family Aradidae, a group of true bugs characterized by their dorsoventrally flattened bodies adapted for living in confined spaces such as under bark or in decaying wood. As of current records, the genus contains multiple species distributed in specific regional contexts, though detailed biological information remains limited in published literature.
Osoriinae
Osoriinae is a subfamily of rove beetles (Staphylinidae) containing over 100 genera organized into multiple tribes. The subfamily is predominantly tropical and subtropical in distribution, with species occurring in leaf litter, under bark, in ant nests, and in tree canopies. Many species exhibit flattened body forms adapted for moving through confined spaces.
Phymatodes testaceus
tanbark borer, violet tanbark beetle
Phymatodes testaceus is a transpalearctic polymorphic longhorn beetle in the subfamily Cerambycinae. Adults range from 6–16 mm in length. The species exhibits significant color variation, with some individuals showing violet or metallic reflections that contribute to the common name 'violet tanbark beetle.'
Platysoma
clown beetles
Platysoma is a genus of clown beetles (family Histeridae) comprising over 80 described species. Members are small, compact beetles that inhabit subcortical environments beneath tree bark. They are predatory throughout their life cycle, specializing in bark beetle prey. The genus is notable among Histeridae for exhibiting facultative egg predation behavior in adults.
Platysoma deficiens
clown beetle
Platysoma deficiens is a species of clown beetle in the family Histeridae. It is found in North America, with distribution records from Canada and the northern United States. As a member of the genus Platysoma, it is presumed to inhabit subcortical environments, though specific ecological details for this species remain limited.
Ptinella
Ptinella is a genus of minute featherwing beetles in the family Ptiliidae, characterized by extreme body miniaturization and reduced wing venation. The genus exhibits remarkable adaptive traits including wing polymorphism (presence of both winged and wingless morphs) and parthenogenesis in some species. These features appear to be evolutionary responses to the spatially and temporally heterogeneous subcortical habitat where members of this genus occur.
Pyrochroinae
fire-colored beetles
Pyrochroinae is a subfamily of Pyrochroidae comprising fire-colored beetles distinguished by their often vivid red, orange, or yellow coloration. The subfamily includes genera such as Pyrochroa, Pseudopyrochroa, Hemidendroides, and Pseudodendroides. Larvae are saproxylic, developing beneath bark and in decaying woody debris of dead trees. Adults of at least some species are canthariphilous, exhibiting specialized cranial gland apparatuses associated with sexual behavior involving cantharidin compounds.
Zabrachia
Zabrachia is a genus of soldier flies (Stratiomyidae) established by Coquillett in 1901. Adults are distinguished from other Pachygastrinae by the fused R4 and R5 wing veins. The genus includes approximately 20 described species distributed across North America, Europe, and Madagascar. Larvae develop under the bark of coniferous trees, while females have been observed ovipositing into pine wood.