A new species of the sharpshooter genus Soosiulus (Insecta: Hemiptera: Cicadellidae: Cicadellini) from the Brazilian Amazon Forest, with notes on a putative complex of species

. Soosiulus belterrensis sp. nov. is described and illustrated from the Amazon Forest of the state of Pará, northern Brazil. Both the male and female terminalia are treated in detail, in addition to color features. With the addition of this new taxon, the diverse Neotropical genus Soosiulus Young, 1977 now comprises 28 species. The new species is the first one proposed for Soosiulus after the original generic description. It appears to be included in a complex with eleven other Soosiulus species, all of them sharing a very similar color pattern. Among the members of this putative complex, the aedeagus of S. belterrensis sp. nov. is most similar to those of S. hastatus Young, 1977 and S. ruber Young, 1977, due to the presence of a pair of conspicuous dorsoapical processes. However, in S. hastatus and S. ruber the aedeagus has also a retrorse ventroapical process originated from a lobe; both process and lobe are not present in the new species. In addition, the female sternite VII in S. hastatus and S. ruber is convex posteriorly, whereas it has a distinct median emargination in the new species.