Passandridae, the "parasitic flat bark beetles," are a family of beetles notable for being one of the very few beetle families with larvae that are, as far as known, exclusively ectoparasitic on the immature stages of other beetles and Hymenoptera.[1][2][3]

Adults are small to moderate sized beetles, 3-35mm, with heavily sclerotized bodies that are either dorso-ventrally compressed (genera occurring under bark) or subcylindrical in cross section (genera inhabiting wood-borer tunnels). Adults are generally brown or black, rarely with a color pattern, with prominent mandibles, confluent gular sutures, thick, moniliform antennae, unequal tibial spurs on the front legs, and generally a characteristic system of grooves and/or carina on the dorsal surface.[4][5]

Larvae are highly modified for their parasitoid habits. First instar larvae are heavily sclerotized, flattened, and spiny. Later instar larvae are physogastric (swollen posteriorly), with simple setae, short unsegmented legs, and reduced mouthparts.[5]

Passandridae consists of 109 described species in nine genera. Only Passandra Dalman occurs in both the Old and New Worlds, being represented in the Neotropical region by a single species, P. fasciata (Gray). The genera Ancistria, Aulonosoma, Nicolebertia, and Passandrina are restricted to the Old World, while Catogenus, Passandrella, Scalidiopsis, and Taphroscelidia are found only in the New World. Only Catogenus and Taphroscelidia occur in the Nearctic. The largest genus is Ancistria, with 34 described species.

Taphroscelidia linearisMontage2
Taphroscelidia linearis
Scientific classification

Erichson, 1845

Ancistria Erichson, 1845
Aulonosoma Motschulsky, 1858
Catogenus Westwood, 1830
Nicolebertia Burck. & Slipinski, 1995
Passandra Dalm. in Schönh., 1817
Passandrella Grouvelle, 1916
Passandrina Reitter, 1878
Scalidiopsis Burck. & Slipinski, 1991
Taphroscelidia Crotch, 1873


  1. ^ Dimmock, G. 1884. Notes on Catogenus rufus. Psyche: 341-342.
  2. ^ Fiske, W.F. 1905. Catogenus rufus, a coleopterous parasite. Proceedings of the Entomological Society of Washington 7: 90-92.
  3. ^ Gravely, F. H. 1916. Some lignicolous beetle larvae from India and Borneo. Records of the Indian Museum 12: 137-175.
  4. ^ Thomas, M.C. 2002. Family 81. Passandridae Erichson 1845. Pp. 327-328 In: Arnett, R. H., Jr., M. C. Thomas, P. E. Skelley, and J. H. Frank (editors). 2002. American Beetles. Vol. 2. Polyphaga: Scarabaeoidea through Curculionoidea. CRC Press, Boca Raton. xiv + 861pp.
  5. ^ a b Burckhardt, D. & S. A. Slipinski. 10.19 Passandridae Blanchard, 1845/Erichson, 1845. p. 363-368. In: Leschen, R.A.B., R.G. Beutel, and J.F. Lawrence. Coleoptera, Beetles. Vol. 2: Morphology and Systematics (Elateroidea, Bostrichiformia, Cucujiformia partim). Handbook of Zoology. Walter de Gruyter, Berlin.

Ancistria is a genus of beetles in the family Passandridae.


Aulonosoma is a genus of beetles in the family Passandridae.


The Boridae are a small family of beetles with no vernacular common name, though recent authors have coined the name conifer bark beetles.


Callirhipidae is a family of beetles in the superfamily Byrrhoidea. It was described by Emden in 1924.


Catogenus is a genus of beetles in the family Passandridae.

Catogenus rufus

Catogenus rufus is a species of parasitic flat bark beetle in the family Passandridae. It is found in North America.

Catogenus thomasi

Catogenus thomasi is a species of parasitic flat bark beetle in the family Passandridae. It is found in North America.


The Chalcodryidae are a family of beetles in the large suborder Polyphaga.


Chelonariidae or turtle beetles is a family of beetles in the superfamily Byrrhoidea. It was described by Blanchard in 1845.


Cucujoidea is a superfamily of beetles. They include many fungus beetles, as well as lady beetles ("ladybugs" or "ladybirds"). Also included are a diversity of lineages of "bark beetles" unrelated to the "true" bark beetles (Scolytinae), which are weevils (superfamily Curculionoidea).


Histeroidea is a superfamily of beetles in the infraorder Staphyliniformia.


Laemophloeidae, "lined flat bark beetles," is a family in the superfamily Cucujoidea characterized by predominantly dorso-ventrally compressed bodies, head and pronotal discs bordered by ridges or grooves, and inverted male genitalia. Size range of adults is 1–5 mm (0.04–0.2 in) in length. Currently, it contains 40 genera and about 450 species, and is represented on all continents except Antarctica; species richness is greatest in the tropics.

Historically, Laemophloeidae was treated as a subfamily of Cucujidae, but starting in the middle of the 20th century, most of what had been treated as subfamilies of the Cucujidae were considered to be families.

Most laemophloeids, adults and larvae, are found under bark of dead trees, where they apparently are primarily fungivores, although some genera with adults having subcylindrical bodies (e.g., Leptophloeus, Dysmerus) occur in the galleries of bark beetles (Curculionidae: Scolytinae), upon which they may feed. A few genera, but most particularly Cryptolestes, contain some species that are pests of stored grain products. The most important of these are C. ferrugineus (Stephens), C. pusillus (Schönherr), and C. turcicus (Grouvelle).Several genera exhibit unusual modifications to male antennae (especially Cryptolestes, Dysmerus, and Microbrontes), with the scape expanded into hook-like or blade-like structures Several other genera (Rhinomalus, Rhinophloeus, and Metaxyphloeus) related to Laemophloeus are atypical in that the adults are rostrate to varying degrees Photographs of most world genera are available at, and most North American species are pictured at,


Passandra is a genus of beetles in the family Passandridae.


Passandrella is a genus of beetles in the family Passandridae.


Passandrina is a genus of beetles in the family Passandridae.


The Rhinorhipidae are a family of beetles, in the large suborder Polyphaga. It contains the single genus Rhinorhipus with a single species Rhinorhipus tamborinensis

Scalidiopsis youngi

Scalidiopsis youngi is a species of beetles in the family Passandridae, and the only species in the genus Scalidiopsis. It was described by Burckhardt and Slipinski in 1991.


Silvanidae, "silvan flat bark beetles", is a family of beetles in the superfamily Cucujoidea, consisting of 58 described genera and about 500 described species. The family is represented on all continents except Antarctica, and is most diverse at both the generic and species levels in the Old World tropics.Silvanids generally are small, brownish, flattened, pubescent and densely punctured beetles ranging from 1.2-15mm in length, and mostly with a 5-5-5 tarsal formula. They have short, strongly clubbed, to very elongate antennae, and frequently grooves or carinae on the head and/or pronotum. Many genera have the lateral margins of the pronotum dentate or denticulate. The family is divided unequally into two subfamilies: Brontinae and Silvaninae. The Brontinae, arranged in two tribes (Brontini and Telephanini) of 10 genera each, are larger, loosely jointed beetles with long antennae, an especially elongate scape, inverted male genitalia, and mandibular mycangia. Both brontine tribes have recently been reviewed at the genus level. The Silvaninae, which has not been divided into tribes, consists of 48 genera of mostly smaller beetles characterized by their closed procoxal cavities, mostly without mandibular mycangia, and non-inverted male genitalia.The largest genera are Telephanus (109 species), Psammoecus (81 species), and Cryptamorpha (27 species) (all Brontinae: Telephanini) and the Old World silvanine genus Airaphilus (35 species). There have been a number of major taxonomic studies in the Silvanidae in recent decades, including Halstead (1973), Sen Gupta and Pal (1996), Pal (1981, 1985), and Karner (1995, 2012).

Investigations into the phylogenetic relationships within the family and between the Silvanidae and other cucujoids are at the preliminary stages. A phylogenetic analysis of the "primitive" cucujoids using morphological characters of larvae and adults found a close relationship between the Silvanidae and Cucujidae. A molecular phylogenetic study primarily aimed at clarifying the status of the more "advanced" cucujoids nevertheless included exemplars of the basal taxa. It showed a close relationship between Passandridae and Silvanidae, and a more distant one with Cucujidae.


Taphroscelidia is a genus of beetles in the family Passandridae.

Extant Coleoptera families


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