Threat Level: Medium

Technomyrmex difficilis is a medium sized uniformly dark species with contrasting pale tarsi. It has a single flat waist segment that is commonly hidden by the gaster. The eyes lie within the outline of the face, erect pilosity is sparsely present on the dorsal surfaces of the mesosoma and occurs more densely on the gaster. All surfaces are dull an unshining. Like all dolichoderines, T. difficilis lacks an acidopore.

The species of several other genera included in PIAkey can be confused with Technomyrmex. Paratrechina is the most likely formicine genus to be confused, but the rows of long thick hairs and acidopore differentiate it from Technomyrmex. The genus can be separated from the sister dolichoderines Linepithema and Iridomyrmex, by its flat petiole. It can be separated from Tapinoma melanocephalum by the presence of a few erect hairs on the mesosoma and by the uniform darkness of its color.

Technomyrmex albipes and T. vitiensis are morphologically very similar to T. difficilis, and can only be differentiated with the aid of a good microscope. Users are referred to the comparison chart for the most reliable taxonomic characters. It should be noted that the hairs referred to can break off of individual specimens, especially older ones. Therefore, it is good practice to examine multiple specimens if available.

Both T. difficilis and T. vitiensis have been repeatedly misidentified as T. albipes in museum collections and in the literature. A thorough taxonomic treatment of the entire genus recently published by Bolton (2007) serves to clarify the taxonomic issues surrounding T. albipes and its relatives.

For a more complete review of the biology, impacts and management of T. difficilis, users are referred to the IUCN/SSC Invasive Species Specialist Group (ISSG) web page. Please note that the discussions of T. albipes on this page most likely also include data from misidentified specimens of T. difficilis and T. vitiensis.

Waist with one segment (petiole) Petiole flat, not raised
Petiole often hidden by gaster
Eyes, in full face view, do not break outline of head
Color of head uniformly dark (including mandibles & antennae)
Erect hair present above level of eye present
Pronotum with one pair of erect hairs
Mesonotum with hairs present
Propodeum with two pair of erect hairs

Chart 1. Technomyrmex species vs. Tapinoma melanocephalum, Linepithema humile, Iridomyrmex anceps group, Paratrechina species

Chart 2. Technomyrmex difficilis vs. T. albipes, T. vitiensis

Chart 1. Technomyrmex species vs. Tapinoma melanocephalum, Linepithema humile, Iridomyrmex anceps group, Paratrechina species

	Technomyrmex spp.	Ta. melanocephalum	L. humile	I. anceps group	Paratrechina spp.
Head
Profile
Petiole	flat, sometimes hidden	flat, sometimes hidden	raised	raised	raised, sometimes hidden
Gaster armed with acidopore	absent	absent	absent	absent	present
Long thick hairs produced in pairs	absent	absent	absent	absent	present
Dorsum of mesosoma with erect hairs	present	absent	absent	present	present
Color of face	uniform	bicolored (antennae & mandibles pale; head dark)	uniform	uniform	uniform
	Technomyrmex spp.	Ta. melanocephalum	L. humile	I. anceps group	Paratrechina spp.

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	T. difficilis	T. albipes	T. vitiensis
Head
Profile
Erect hairs above level of eye	present	absent	absent
Pairs of erect pronotal hairs	one	two	one
Pairs of erect mesonotal hairs	one	absent	absent
Pairs of erect propodeal hairs	one	two	one
	T. difficilis	T. albipes	T. vitiensis

• Antweb: specimen images, data & maps
  
  
• Bolton, B. (2007) Taxonomy of the Dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker caste. Contributions of the American Entomological institute, 35, 1-150.
  
  
• Bolton, B. (1995) A new general catalogue of the ants of the world. Harvard University Press, Cambridge, Massachusetts, 504 pp.