ID guide | introduced ants

Technomyrmex pallipes

Diagnostic description: 

Diagnosis among workers of introduced and commonly intercepted species. Antenna 12-segmented. Antennal scape length less than 1.5x head length. Eyes medium to large (greater than 5 facets); eye length not distinctly greater than length of cephalic hair. Antennal sockets and posterior clypeal margin separated by a distance less than the minimum width of antennal scape. Mandible lacking distinct basal angle. Dorsum of mesosoma with metanotal groove, but never with a deep and broad concavity; erect hairs present. Propodeum and petiolar node both lacking a pair of short teeth. Propodeum lacking posteriorly projecting protrusion; with dorsal surface distinctly shorter than posterior face. Waist 1-segmented (may be hidden by gaster). Petiolar node appearing flattened. Gaster armed with ventral slit; with five plates on its dorsal surface. Distinct constriction not visible between abdominal segments 3+4. Dorsum of head with 2 pairs of short and stubby hairs posterior to eye. Pronotum with 1–3 pairs of erect hairs. Mesonotum with erect hairs. Propodeum with 2 (rarely 3) pairs of erect hairs. Color uniformly dull brown; hind tarsus not distinctly lighter in color than hind femur.

Technomyrmex pallipes can be distinguished from Brachymyrmex species, with which it bears superficial resemblance, by the 12-segmented (versus 9-segmented) antenna, and by the presence of a ventral slit (versus acidopore) on the gaster tip. It can be differentiated from Technomyrmex species by the absence (versus presence) or erect hairs on the mesosoma, and by the gaster which has 4 plates on the dorsal surface and 6 on the ventral surface (versus 5 plates on both surfaces). It is most easily differentiated from Tapinoma sessile by the bicolored with dark head and light body, gaster and appendages (versus uniform brown color). Technomyrmex pallipes is distinguished from its fellow introduced congeners by the following combination of characters: (1) Dorsum of head with 2 pairs of short and stubby hairs posterior to eye; (2) 1–3 pairs of erect hairs on pronotum, 2 pairs on propodeum, erect hairs present on mesonotum; (3) hind tarsus not distinctly lighter in color than hind femur. This last character is the easiest way to separate T. pallipes from its fellow introduced congeners.

Look alikes: 

Brachymyrmex, Tapinoma sessile, Technomyrmex albipes, Technomyrmex difficilis, Technomyrmex vitiensis

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith