This is the eighth in a series of papers reviewing the subgenera of the economically important fruit fly genus Bactrocera Macquart, made possible by the revisions of Australasian and Southeast Asian species by Drew (1989) and Drew and Romig (2013) respectively. This paper deals with subgenera Hemisurstylus Drew and Paratridacus Shiraki, which are considered here to be synonymous and to contain six described species. Paratridacus is distinguished by a broadly rounded posterior surstylus lobe and absence of the pecten on abdominal tergite III in males, the presence of 2 pairs of scutellar setae and elongate lateral postsutural yellow vittae. It is distributed from eastern and southern Asia to Papua New Guinea and Australia and is placed in the Melanodacus group of subgenera as defined by Drew (1989). Known host plants are Garcinia spp (Clusiaceae) and no species has been attracted to known male lures. Five additional species from Papua New Guinea and Maluku, included by Drew (1989) or Drew and Romig (2013, 2016), were transferred to other subgenera by Hancock and Drew (2016, 2017b).