Dolichoderus ypsilon Forel

Dolichoderus ypsilon Forel

(Fig. 27)

Dolichoderus scabridus ypsilon Forel, 1902: 461 (raised to species by Forel, 1907: 284, Clark, 1930: 258).

Types. 4 worker syntypes from Perth [approx. 31°57'S 115°51'E], Western Australia (1 in ANIC, 3 in MHNG); 1 worker syntype from Lion Hill [approx. 31°53'S 116°12'E], South Australia (MCZC).

Diagnosis. Pronotum rounded, lacking spines; propodeum with elongate spines directed upward at angle of 45° or less to horizontal plane, the angle between them at least 90°; dorsum of petiolar node angular, base of propodeal spines forming a "V" with a narrowly rounded angle connecting their bases; legs entirely light red or orange.

This species can be distinguished from D. inferus and D. scabridus by the dorsum of its petiolar node being angular rather than broad, and the base of the propodeal spines forming a narrowly angled "V" rather than a broad "U" when viewed from the front. Additionally, D. ypsilon can be distinguished from D. rufotibialis and D. niger by the distinctive colour of its entirely red or orange legs.

Worker description. See Fig. 27. Generally as figured but with legs more yellow (slightly less red) in some individuals. Also, a few specimens have the sculpturing on the mesosomal dorsum reduced medially, this region being nearly smooth (sculpturing is as figured laterally in these individuals).

Measurements (n=5). CI 92–96; EI 20–25; EL 0.21–0.29; HL 1.14–1.29; HW 1.05–1.22; ML 1.60–1.81; MTL 0.95–1.15; PronI 69.93–74.15; PronW 0.76–0.90; SI 109–118; SL 1.22–1.36.

Material examined. Western Australia: 28mi. ESE Ravensthorpe (Greaves,T.) (ANIC); 32km S Dwellingup (Naumann,I.D. & Cardale,J.C.) (ANIC); 45mi. E Esperance (Lowery,B.B.) (ANIC); 9mi. W Zanthus (Taylor,R.W.) (ANIC); Alcoa via Jarrahdale (collector unknown) (JDMC); Armadale (Clark,J.) (ANIC); Australind (Heterick,B.E.) (JDMC); Beechboro (Lowery,B.B.) (ANIC); Boyanup (collector unknown) (ANIC); Canning Reservoir, 11km E Armadale (Weir,T.A.) (ANIC); Dwellingup (Majer,J.D.) (ANIC, JDMC); Gleneagle (Springett,J.) (ANIC); Hope Valley (Heterick,B.E.) (JDMC); Jarrahdale (Douglas,A.M. & Douglas,M.J.) (ANIC); Kalamunda (Greaves,T.) (ANIC); Kings Park (Lowery,B.B.) (ANIC); Ludlow (Clark,J.) (ANIC); Mt. Cooke (Heterick,B.E.) (JDMC); Mundaring (Clark,J.) (ANIC); nr. Mundaring (Springett,J.) (ANIC); Perth (Chase; Clark,J.; Greaves,T.) (ANIC); Pinjarrah- Williams Rd. (Heterick,B.E.) (JDMC); Pink Lake (Esperance) (Heterick,B.E.) (JDMC); Swan River (Clark,J.) (ANIC); Yanchep (Greaves,T.) (ANIC); Yarra Rd. (off Brookton Hwy) (Heterick,B.E.) (JDMC).

Comments. This species is restricted to south-west Western Australia. The male was described by Forel (1907).