Polyergus longicornis, Trager, James C., 2013

Trager, James C., 2013, Global revision of the dulotic ant genus Polyergus (Hymenoptera: Formicidae, Formicinae, Formicini), Zootaxa 3722 (4), pp. 501-548 : 525-526

Polyergus longicornis new status

Figures 30, 31, 32

Polyergus lucidus longicornis M. R. Smith 1947: 155 . Syntype workers: USA, SOUTH CAROLINA, Florence [USNM, 57661] (images examined). New status.

Types not measured.

Measurements (N=18) HL 1.60–1.80 (1.71), HW 1.52–1.72 (1.62), SL 1.67–1.89 (1.77), ½ VeM 13–22 (17.78), ½ PnM 0–9 (3.78), WL 2.52–2.88 (2.73), GL 2.08–2.68 (2.34), HFL 2.22–2.56 (240), CI 91–99 (95), SI 101–117 (109), HFI 139–158 (149), FSI 130–144 (136), LI 4.16–4.68 (4.44), TL 6.44–7.32 (6.78).

Worker description. Head truncate-obovate to narrowly subhexagonal, generally more strongly tapering behind than in front of the eyes, HL> HW; with conspicuous and abundant vertex pilosity of 20–40 erect macrosetae; scapes at least equaling to notably longer than head, always surpassing vertex corners, gradually thickening apically, not notably clavate; pronotum with (3) 6–12 (18) erect macrosetae; mesonotal profile flat or very weakly convex for most of its length; propodeal profile evenly rounded, its dorsal and posterior faces indistinct; petiole a little narrower than propodeum, with convex sides, these convergent dorsad; petiolar dorsum convex, not emarginate; petiole in profile tapering and usually slightly recurved dorsad; first tergite very sparsely pubescent or completely lacking pubescence; first tergite pilosity sparse, usually a few on the anterior half, but these often deciduous; the macrosetae weakly flexuous.

Head matte; mesosoma matte; gaster weakly matte.

Color red with infuscation of appendages and posterior portions of tergites.

Discussion. P. longicornis is most likely to be confused with ruber and especially sanwaldi . Polyergus longicornis is distinguished from the largely sympatric ruber by its more abundant vertex pilosity, ½ VeM 13 + vs. 12 or less, nearly uniformly matte mesosoma and cephalic integument, and parasitism of F. do l o s a rather than F. biophilica . Polyergus longicornis is distinguished from the allopatric, more northern P. sanwaldi by its proportionally longer scapes and legs, and its slightly narrower head ( Fig. 2 ).

Etymology. Smith coined the name of this ant species as an adjective, from Latin “longus” + “cornus”, referring to its long scapes.

Natural history. Polyergus longicornis is a southeastern species, known from the Carolinas and Georgia, west to Mississippi. It is found in the open pinelands and oak-pine woodlands on sandy soils with host populations of F. dolosa .

Distribution of studied specimens. FLORIDA Leon Co. Apalachicola Nat’l For. Rd. 307. Stand 246 June 2004 JR King Colony Series, Pine Flatwoods (JCTC); MISSISSIPPI Oktibbeha Co. Osborn 33o30’41”N 88o44’08”W 19 June 2003 J. G. Hill (MEM); MISSISSIPPI Pontetoc Co. Natchez Trace, mi. 247.5. 34o05’49”N 88o51’38”W 23 June 2003 JA MacGown (MEM); MISSISSIPPI Winston Co. Tombigbee Nat’l Forest 33o2’30”N 89o04’32”W. 10 July 2003 JA MacGown (MEM); NORTH CAROLINA Mecklenburg Co. Davidson 6-VI-39 CS Brimley (NCSU); NORTH CAROLINA Staley 15-VIII-1968 DL Wray (NCSU); NORTH CAROLINA Moore Co. Robbins in yard 7-VII-1985 Morris (NCSU); SOUTH CAROLINA McCormick Co. Baker Cr. St. Pk. Open pineland 28 June 1986 C Johnson (JCT).

Figures

FIGURE 2. Scatter plot comparing head length / scape length ratios of Polyergus longicornis and Polyergus sanwaldi.

FIGURES 30 – 32. Lateral, full face, and dorsal views of Polyergus longicornis worker CASENT 0281044. Photographs by Shannon Hartman from www. AntWeb. org.