Threat Level: Low

Paratrechina vaga is a small species that comes in various shades of reddish brown. The eyes lie within the outline of the head, rows of long thick and dark hairs occur on the body and head, and the appendages are of moderate length. The petiole is upright and, like all formicines, the gaster is armed with an acidopore. There are no characters that can reliably identify P. vaga in the field, and an accurate identification is even difficult with the aid of a microscope.

Paratrechina bourbonica is the species most often confused with P. vaga. The most reliable character used to differentiate between them is the amount of appressed pilosity found on the mesopleuron. The mesopleuron of Paratrechina bourbonica is typically covered in a dense pelt of short appressed hairs while that of P. vaga is typically glassy smooth with at most a sparse scattering of short appressed hairs. While this character often works, there are some specimens in which the pilosity appears intermediate. See P. bourbonica for a more extensive discussion of the two.

Paratrechina vaga, as it is currently defined, encompasses a broad spectrum of morphological variation. The species demonstrates a wide variation in color, size and pilosity.

Little is known about the effects P. vaga has on ecological or agricultural systems.

Paratrechina is a diverse genus with many taxonomically difficult species that occur in the Pacific region. If a specimen does not match the description or images of species included in PIAkey, it is very possible that it is either a native species or a different introduced species.

Waist with one segment (petiole) Petiole raised, not flattened Petiole can be obscured by gaster
Gaster armed with acidopore
Long, dark, thick hairs produced in pairs on body
Long, dark, thick hairs produced in pairs on head
Eyes inside outline of head
Antennal scape length less than 1.5 times head length
Mesopleuron with few hairs (usually < 20)

	P. vaga	P. bourbonica	P. longicornis
Head
Profile
Antennal scape length relative to head length	< 1.5x length of head	< 1.5x length of head	~ 1.5x length of head
Eyes break outline of face	no	no	yes
Hairs on mesopleuron	sparse (usually < 20)	abundant (usually > 20)	sparse (usually < 20)
Color of hairs	dark	dark	white
	P. vaga	P. bourbonica	P. longicornis

• Antweb: specimen images, data & maps
  
  
• Bolton, B. (1995) A new general catalogue of the ants of the world. Harvard University Press, Cambridge, Massachusetts, 504 pp.
  
  
• Wilson, E.O. & Taylor, R.W. (1967) The ants of Polynesia (Hymenoptera: Formicidae). Pacific Insects Monograph, 14, 1-109.