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 family and a spelling correction (emendation) has been suggested that also avoids the confusion created by homonyms. The family name Urolabididae has also been used for some members in the past.[1]
This family has about 100 species, with distribution limited mainly to eastern Asia. 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 and has a ringed appearance. The simple eyes or ocelli, when present (Urolabida lacks ocelli[2]), 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.[3] They suck plant sap.[4][5] The male reproductive anatomy suggests close affinities to the Tessaratomidae subfamily Natalicolinae. The spermatheca has two pump flanges in two genera which is a feature found also in the Aradidae and Leptopodidae. Thus the phylogeny of the group is unclear but lies within the Pentatomoidea.[6]
In the past the family was divided into two subfamilies, but one group, the Saileriolinae, has since been suggested as a distinct family, Saileriolidae, by at least two studies. The position of Saileriolidae within the Pentatomoidea is still unclear.[3][7]
^Schuh, Randall T.; Slater, James Alexander (1995). True Bugs of the World (Hemiptera:Heteroptera): Classification and Natural History. Cornell University Press. pp. 245–246.
^Kumar, R. (1971). "Morphology and relationships of the Pentatomoidea (Heteroptera) 5-Urostylidae". American Midland Naturalist. 85 (1): 63–73. doi:10.2307/2423912. JSTOR2423912.
^Yao, Yunzhi; Cai, Wanzhi; Rider, David A.; Ren, Dong (2012). "Primipentatomidae fam. nov. (Hemiptera: Heteroptera: Pentatomomorpha), an extinct insect family from the Cretaceous of north-eastern China". Journal of Systematic Palaeontology. 11: 1–20. doi:10.1080/14772019.2011.639814. S2CID86753502.