Perittopus zhengi is a species of riffle bug from Thailand (Chiang Mai Province).[1] It was described in 2013 by Zhen Ye, Pingping Chen and Wenjun Bu, and is named after Professor Leyi Zheng.[1] Its authors placed it to the "eastern species group" within genus Perittopus.[1]
Specimens of both sexes are orange and brown and have dark brown, segmented antennae. Among wingless (apterous) specimens, females are longer than their male counterparts at respectively 3-3.1&mm and 2.7 mm body length. For winged (macropterous) specimens, this is the other way around: winged males are, at 3.4-3.5 mm, slightly larger than winged females, which measure 3.2-3.3 mm.[1]
Specimens resemble those of Perittopus asiaticus, to which it is closely related and with which it may co-occur.[1] Winged female specimens of both species are particularly difficult to reliably tell apart.[1]