Urostylididae is a family of true bugs and is considered a
basal or "primitive" family within the stink-bug lineage. They are found only in Asia. Older works used the spelling Urostylidae but this clashes with the name used for a
protozoan
Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...
family and a spelling correction (
emendation) has been suggested that also avoids the confusion created by
homonyms
In linguistics, homonyms are words which are either; ''homographs''—words that mean different things, but have the same spelling (regardless of pronunciation), or ''homophones''—words that mean different things, but have the same pronunciatio ...
. The family name Urolabididae has also been used for some members in the past.
This family has about 100 species, with distribution limited mainly to
eastern Asia
East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of China, Japan, South Korea, and Taiwan ...
. Urostylidids are 4 to 15 mm and somewhat longer than broad with elongated legs, three
tarsal segments, and a small head. The
antenna has 5 segments of which the first is longer than the head. The base of the antenna has broad
tubercles
In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal.
In plants
A tubercle is generally a wart-like projection, b ...
and has a ringed appearance. The simple eyes or ocelli, when present (''
Urolabida'' lacks ocelli), are very close to each other. They show a wide separation between the hind and mid coxae on the underside. Other important family characters are the presence of a structure for stridulation, the stridulitrum on the first anal vein of the hind wing, and bristles on the claws. The female genital structure has nine gonocoxites that form a M or W-shaped sclerite.
They suck plant sap.
The male reproductive anatomy suggests close affinities to the
Tessaratomidae
Tessaratomidae is a Family (biology), family of Hemiptera, true bugs. It contains about 240 species of large bugs divided into 3 subfamily, subfamilies and 56 genus, genera.
Tessaratomids resemble large stink bugs (family Pentatomidae) and are s ...
subfamily
Natalicolinae. The
spermatheca
The spermatheca (pronounced : spermathecae ), also called ''receptaculum seminis'' (: ''receptacula seminis''), is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, Oligochaeta worms and certain other in ...
has two pump flanges in two genera which is a feature found also in the
Aradidae
Aradidae is a family of true bugs (Heteroptera). Family members are commonly known as flat bugs due to their dorsoventrally flattened bodies. With few exceptions, these cryptic insects are of no economic importance.
Aradids are 3 to 11 mm long ...
and
Leptopodidae
Leptopodidae is a family of spiny-legged bugs in the order Hemiptera. There are about 15 genera and more than 40 described species in Leptopodidae.
Genera
These 17 genera belong to the family Leptopodidae:
* '' Erianotoides'' J.Polhemus & D.Pol ...
. Thus the phylogeny of the group is unclear but lies within the Pentatomoidea.
In the past the family was divided into two subfamilies, but one group, the Saileriolinae, has since been suggested as a distinct family,
Saileriolidae
Saileriolidae is a family of true bugs and is considered a Basal (phylogenetics), basal or "primitive" family within the stink bug lineage. They are found only in Asia. Originally included within the family Urostylididae,China, W.E., Slater, J.A. ...
, by at least two studies. The position of Saileriolidae within the Pentatomoidea is still unclear.
References
Shield bugs
Heteroptera families
{{Pentatomoidea-stub