Pheidole tobini ^HNS new species

Types Mus. Comp. Zool. Harvard.

Etymology Named after John E. Tobin, one of the collectors, and a student of the Amazon arboreal ant fauna.

diagnosis A member of the fallax ^HNS group, similar to fallax ^HNS, jelskii ^HNS, obscurithorax ^HNS, puttemansi ^HNS, roushae ^HNS, and valens ^HNS, and distinguished as follows.

Major: dark brown; head narrowed toward occiput in side view, and subrectangular in full-face view; occipital cleft deep; posterior fourth of head, including occiput, and frontal lobes longitudinally carinulate, contrasting with the mostly rugoreticulate anterior threefourths of the head; humerus in dorsal-oblique view subangulate; petiolar peduncle thin, and node in side view tapering almost to a point at the apex; anterior half of the first gastral tergite shagreened and opaque. Minor: occiput constricted to a neck with a broad nuchal collar; petiolar peduncle slender. Measurements (mm) Holotype major: HW 1.68, HL 1.80, SL 1.00, EL 0.22, PW 0.80. Paratype minor: HW 0.56, HL 0.82, SL 1.12, EL 0.14, PW 0.44.

Color Major: head dark reddish brown, body dark and in some places blackish brown.

Minor: head, mesosoma, and petiolar peduncle medium brown; gaster and rest of waist light brown; appendages light brown.

Range Known only from the type locality.

Biology The type colony was found in terra firme rainforest, nesting in an epiphyte mass on a large fallen tree. A second colony was discovered at the same locality and habitat, nesting beneath the bark of a fallen log at the edge of a tree gap.

Figure Upper: holotype, major. Lower: paratype, minor. PERU: Cuzco Amazonico, 15 km northeast of Puerto Maldonado, Madre de Dios (Stefan Cover and John E. Tobin). Scale bars = 1 mm.