Zaprionus neglectus is a continental species lacking F1 ornamentation and the hairy brush on F1 basitarsus in males (Collart 1937b; Fig. 5a). It is the only species previously belonging to the inermis group to lack such a secondary sexual character. Two species of the spinosus subgroup of the armatus group also lack the male hairy brush. Burla (1954) and Lachaise and Tsacas (1983) described that Zaprionus neglectus bred on decaying fruits and in flowers of Ipomoea and Crinum. Chassagnard and McEvey (1992) described a species, Zaprionus simplex, lacking F1 ornamentation and the male hairy brush from Madagascar. They also noted that some specimens were “collected from Crinum sp. flowers but no evidence was found that it bred therein” (p. 322).

We have recently collected a strain of Zaprionus simplex from Crinum sp. in Madagascar and reared it in the laboratory. Burla (1954) noted the presence of two long caecae around the ejaculatory bulb in males of Zaprionus neglectus. Dissection of cultured males of Zaprionus simplex also revealed the presence of long caecae in the Malagasy strain. Wing shape indices were also strongly similar in the original descriptions of the two species. Hence, Zaprionus simplex Chassagnard & McEvey is considered a junior synonym to Zaprionus neglectus Collart. Yassin et al. (2008a) suggested in light of morphological characters Zaprionus simplex, syn. n. to belong to the armatus group, but in the lack of molecular data of any species of this group such relation remains questionable. Indeed, the species has more than 2 epandrial bristles and lacks any F1 ornamentation. Molecular analysis of the Malagasy strain showed the species to be the earliest branch of the subgenus not belonging to any of the three other species groups (Yassin et al., in press). Thus, a group is erected for this single species.