Diaphoromyrma sofiae

Diaphoromyrma workers are characterized by the following traits: Antenna 9-segmented with 2-segmented club, trapezoidal promesonotum in dorsal view, propodeal spiracles situated on the propodeal edges, and the fourth abdominal sternite with a pair of rounded recurved anterolateral extensions which curve up onto the dorsal surface of the segment. Apparently Diaphoromyrma is close to the genera Allomerus and Diplomorium in the Solenopsidini, but its tribal attribution remains difficult because of the inadequate resolution of the phylogenetic relationships within the Myrmicinae. The combination of traits differentiates this thus far monotypic genus from any other myrmicine. The unique shape of the promesonotum, trapezoidal in dorsal view and with well defined angles at the sides; the comparatively high and narrow petiolar node, contrasting with the broader, low and round postpetiolar node, the low position of the insertion of the postpetiole on the anterior face of first gastral segment, and the dorsal extensions of abdominal sternite 4 are unique and represent potential apomorphies of Diaphoromyrma. Usually in myrmicine ants the dorsal margin of the postpetiole is higher than the top of first gastral tergite, in lateral view. …

The genus is known only from workers from Bahia, Brazil. The species was collected in litter samples taken in three rain forest remnants in the extreme southern portion of Bahia using the Winkler extraction. The landscape is dominated by forested valleys inserted in the coastal plateau (Barreiras Formation, Tertiary origin). Most of the vegetation of the remnants was in an initial or medium stage of regeneration, in a region where eucalypt plantations currently predominate.