Eastern vs Mexican vs Slough Amerwing

Three amberwing species (Perithemis sp.) breed in Arizona: the Mexican, Slough, and Eastern Amberwings. All are characterized by small size, rounded wings, and generally orange color. The Mexican Amberwing is widespread throughout the southwestern half of the state whereas the distribution of the other two species, in particular the Slough Amberwing, is restricted to the southeast corner of Arizona (Paulson 2009, but see News for a 2010 extralimital record of the Slough Amberwing).

Male Comparison

Thorax and legs

Males are separated based on leg color, thorax and abdomen color pattern, wing color and venation, and behavior as follows:

  • Mexican and Eastern Amberwing: legs are orange
  • Slough Amberwing: outside of legs is dark.
  • Mexican Amberwing: thorax orange-yellow, weakly patterned
  • Slough Amberwing: thorax markedly striped with brown and yellow
  • Eastern Amberwing: thorax markedly patterned with two yellow (pale) lateral stripes.

Thorax and legs of the male Mexican, Slough, and Eastern Amberwings, AZ.

Abdomen

  • Mexican Amberwing: not/weakly patterned
  • Slough Amberwing: dark brown marks on abdominal segments are parallel
  • Eastern Amberwing: markedly patterned with yellow stripes forming triangular chevrons on most segments.

Dorsal views of the middle abdominal segments of the male Mexican, Slough, and Eastern Amberwings, AZ.

Wings

  • Mexican Amberwing: stigmas and wing veins yellow-orange
  • Slough and Eastern Amberwings: stigmas orange-red.

Wing venation

  • Mexican Amberwing: triangles usually have cross-veins
  • Slough Amberwing: triangles not cross-veined, but forewing subtriangle usually has one cross-vein
  • Eastern Amberwing: triangles usually not cross-veined.

Detail of the forewing venation of the male Mexican, Slough, and Eastern Amberwings, AZ.

Behavior

  • Mexican and Eastern Amberwings generally perch at sunny locations
  • Slough Amberwing prefers to perch in the shade.
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