Piesmatidae

Taxobox
name = Ash-grey leaf bugs


image_width = 240px
image_caption =
regnum = Animalia
phylum = Arthropoda
subphylum = Hexapoda
classis = Insecta
subclassis = Pterygota
infraclassis = Neoptera
superordo = Paraneoptera
ordo = Hemiptera
subordo = Heteroptera
infraordo = Pentatomomorpha
superfamilia = See text
familia = Piesmatidae
familia_authority = Amyot & Audinet-Serville, 1843
diversity_link = Piesmatidae
diversity = 3 genera, c. 40 species
subdivision_ranks = Genera
subdivision =
* "Mcateella"
* "Miespa"
* "Piesma"and see text.
synonyms ="Zosmenidae" Dorhn, 1859

Piesmatidae is a small family of true bugs, commonly called ash-grey leaf bugs. It contains a mere three living genera with about 40 described species altogether. The Piesmatidae are distributed mostly in the temperate Northern Hemisphere, with some occurring in Africa, Australia and South America. A common species found throughout the Americas is "Piesma cinereum".Grimaldi & Engel (2007)]

Ash-grey leaf bugs are small insects, some 2-4 mm overall. The head, thorax and the firm part of the wings are extensively dimpled. This resembles the similar pattern of the Tingidae of the infraorder Cimicomorpha, and was initially taken to signify a close relationship. It is due to convergent evolution however.

They feed on plant sap, mostly of Chenopodiaceae and Caryophyllaceae. "Piesma linnavouri" and "Mcateella" have been found on "Acacia" (Fabaceae). The host plants of "Miespa" remain unknown.

ystematics

Three-quarters of the named species are in the type genus "Piesma", from which the subgenera "Afropiesma" and "Parapiesma" are sometimes split off. The genus "Thaicoris" was for some time placed here, but is now recognized to be a member of the Thaumastocoridae.

There are three fossil genera. "Cretopiesma" was found in mid-Cretaceous amber from Myanmar and lived about 100 mya (million years ago). "Eopiesma" from the earliest Eocene (about 55 mya) is still a very basal member of the family. "Heissiana", found in Baltic amber from the Eocene might be a northern relative of "Mcateella" and "Miespa" but given its distribution it might more comfortably be considered closely related to the ancestor of "Eopiesma".

The closest relatives of the Piesmatidae remain rather insufficiently determined. After the ash-grey leaf bugs were recognized as Pentatomomorpha, they were most often placed in the Lygaeoidea based on cladistic analysis, with their relatives variously presumed to be the Berytidae, Colobathristidae and Malcidae, or the peculiar, beetle-like Psamminae, a subfamily of the Lygaeidae. For some time, the Psamminae were even included in the Piesmatidae.

Alternatively, the ash-grey leaf bugs were considered Pentatomomorpha "incertae sedis" or placed in a monotypic superfamily Piesmatoidea. With the discovery of "Cretopiesma", this view seems perhaps the most warranted one. The origin of the Pentatomomorpha cannot lie much before the Early Cretaceous, and from the same time as "Cretopiesma" the Aradoidea genus "Archearadus" is known which resembles the most ancient piesmatid very much. Therefore, the Piesmatidae are indeed best considered "incertae sedis" among the Pentatomomorpha, until a cladistic analysis including the Cretaceous fossils can clarify the relationship between Aradoidea and Lygaeoidea.

Footnotes

References

* (2007): An Unusual, Primitive Piesmatidae (Insecta: Heteroptera) in Cretaceous Amber from Myanmar (Burma). "American Museum Novitates" 3611: 1-17. DOI:10.1206/0003-0082(2008)3611 [1:AUPPIH] 2.0.CO;2 [http://digitallibrary.amnh.org/dspace/bitstream/2246/5909/1/N3611.pdf PDF fulltext]