Five species of the Neotropical genus Phalaecus Stål, 1862 were known up to now: P. lineatus Grazia, 1983, P. nigromaculatus Grazia, 1983, P. paraense Grazia, 1983, P. pustulatus (De Geer, 1773), and P. ruckesi Grazia, 1983. Phalaecus pustulatus was the only species mentioned from French Guiana. We mention here the first records of P. lineatus, P. nigromaculatus, and P. ruckesi to French Guiana. The female of P. lineatus is described for the first time, and a new species, Phalaecus carmini n. sp., is described. An identification key of the five adult Phalaecus species found in French Guiana is proposed, and color pictures of the habitus are given for the first time.
Heteroptera, Pentatomoidea, Pentatomini, South America, Neotropics, Amazon rainforest, new species.