Pseudomyrmex satanicus ( Wheeler 1942 )

Ward, Philip S., 1993, Systematic studies on Pseudomyrmex acacia-ants (Hymenoptera: Formicidae: Pseudomyrmecinae), Journal of Hymenoptera Research 2, pp. 117-168 : 149

Pseudomyrmex satanicus ( Wheeler 1942)

(Figs. 10, 20, 59, 68)

Pseudomyrma satanica Wheeler 1942: 174 . Syntype workers, queen, male, Rio Agua Salud , Canal Zone, Panama (W. M. Wheeler) ( AMNH, LACM, MCZC) [Examined], One MCZC syntype worker here designated LECTOTYPE .

Pseudomyrmex satanica [sic] (Wheeler); Janzen 1966:252.

Pseudomyrmex satanicus (Wheeler) ; Kempf 1972:223.

Worker measurements (n= 15). - HL 1.16-1.36, HW 1.10-1.26, MFC 0.035-0.057, Cl 0.90-0.97, REL 0.45-0.50, REL2 0.48-0.52, OOI 0.92-1.67, VI 0.69-0.78, FCI 0.030-0.049, SI 0.45-0.49, SI2 0.88-1.00, NI 0.63-0.68, PLI 0.47-0.54, PWI 0.46- 0.63, PPWI 1.35-1.54.

Worker diagnosis. - Similar to P. spinicola (q.v.) except as follows. Larger (HW> 1.09), head broader (Cl> 0.88) (Fig. 34) with straight or slightly concave posterior margin and subangulate posterolateral comers (Fig. 10). (The posterior margin of the head approaches this condition in some P. spinicola workers but these have much smaller, more elongate heads, HW <1.10, Cl <0.90.) Median clypeal lobe narrower (CLW / HW 0.20-0.22; see Fig. 33).

Palp formula 4,3. Head with pronounced pit-like impression below the median ocellus (absent or poorly developedinP. spinicola ). Metanotal groove better developed, longer. Petiole tending to be more slender, with less distinct posterolateral corners (this characteristic seen in some workers of P. spinicola , especially individuals from Panama). Body pubescence averaging thicker than in P. spinicola . Dark brown in color, mandibles and appendages lighter.

Comments. - The foregoing diagnosis will allow discrimination of P. satanicus workers from those of the closely related P. spinicola', queens can be recognized by size alone (HL> 1.65, HW> 1.20). P. satanicus can be distinguished from the remaining members of the P. ferrugineus group by the emarginate, laterally angulate median clypeal lobe of the worker and the large size of the queen.

Distribution and biology. - P. satanicus is a forest species restricted to a few localities in central Panama where its host plant, Acacia melanoceras , grows (Fig. 68). Both the ant and plant are intolerant of forest clearance and are considered vulnerable to extinction ( Janzen 1974). The ant is polygynous, with 5-20 or more queens per colony, and the workers are particularly aggressive, even for acacia-ants ( Wheeler 1942; Janzen 1974). See Janzen (1974:43-53) for additional details on P. satanicus and its host plant.

Material examined ( AMNH, LACM, MCZC, PSWC, USNM). -

PANAMA Canal Zone: " Canal Zone " (A.H.Jennings) ; 3mi SW Gatuen Dam (D.H.Janzen) ; Barro Colorado Island (D.H.Janzen) ; France Field (G.C.Wheeler) ; Marajal [Majagual] nr. Colon (W.M.Wheeler) ; Red Tank (W.M.Wheeler) ; Rio Agua Salud (W.M.Wheeler) ; Zorra Island (D.H.Janzen) ; Panama: Rio Piedras (D.H.Janzen) ; prov.unknown: “Panama” (c.u.) .