Passandridae, the "parasitic flat bark beetles," are a family of

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s 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. 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 (antenna with equally sized spherical segments that looks like a string of beads), unequal tibial spurs on the front legs, and generally a characteristic system of grooves and/or carina on the dorsal surface.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.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. Larvae are highly modified for their parasitoid habits. First

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

larvae are heavily sclerotized, flattened, and spiny. Later instar larvae are physogastric (swollen posteriorly), with simple setae, short unsegmented legs, and reduced mouthparts. The larvae are especially associated with woodboring insects, as

longhorn beetles The longhorn beetles (Cerambycidae), also known as long-horned or longicorns, are a large family of beetles, with over 35,000 species described. Most species are characterized by extremely long antennae, which are often as long as or longer than ...

and

weevils Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and herbivorous. Approximately 97,000 species of weevils are known. They belong to several families, ...

. The adults are likely predaceous. 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. They are members of the superfamly

Cucujoidea Cucujoidea is a superfamily of beetles. This group formerly included all of the families now included in the superfamily Coccinelloidea. They include some fungus beetles and a diversity of lineages of "bark beetles" unrelated to the "true" bark be ...

. The oldest record of the family is '' Mesopassandra,'' from mid-Cretaceous (latest

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0 ...

-earliest Cenomanian) aged

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The ...

from Myanmar, around 100 million years old, which is placed in its own subfamily as the most primitive known member of the group.

References

{{Taxonbar, from=Q756535 Cucujoidea families