Pseudomyrmex championi (Forel)

Ward, Philip S. & Branstetter, Michael G., 2022, Species Paraphyly and Social Parasitism: Phylogenomics, Morphology, and Geography Clarify the Evolution of the Pseudomyrmex elongatulus Group (Hymenoptera:, Insect Systematics and Diversity 6 (1), pp. 1-31 : 19-20

Pseudomyrmex championi (Forel)

Figs. 6 and 21

Pseudomyrma championi Forel 1899: 96 . Syntype worker, Amula, 6000 ft., Guerrero, Mexico (H. H. Smith) (BMNH) [examined].

Pseudomyrma leonhardi Stitz 1937: 132 . Two syntype workers, Guerrero, Mexico (L. Schultze) (ZMHB) [examined]. Synonymy by Kempf 1961: 391.

Pseudomyrmex championi (Forel) ; Wheeler and Wheeler 1956: 382. Combination in Pseudomyrmex .

Pseudomyrmex championi (Forel) ; Kempf 1961: 391-393 (in part).

Other material examined ( AMNH, CASC, CUIC, CZUG, EMEC, IEXA, JTLC, KWJC, LACM, MCZC, MHNG, MNHN, MSNG, MZSP, OSAC, PSWC, SEMC, UCDC, UCRC, USNM).

Mexico: Chihuahua: 6.5 km NW Batopilas , 1,550 m (Ward, P. S.) ; Mpio. Ocampo, 16 k E Basaseachic (Mackay, W.; Mackay, E.);

Ciudad de México: Cd. de México, Jardín Botánico UNAM, 2,344 m (Dubovikoff) ; Colima: 16 km NNE Comala , 1,280 m (Ward, P. S.) ; Guanajuato: 5 mi S Salvatierra (Schlinger, E. I.) ; Guanajuato [as ‘Guanaxuato’] (Dugès, E.) ; Guerrero: Xucumanatlan , 2,135 m (Smith, H. H.) ; Hidalgo: 11 mi W Jct. 45 & 85, 1,980 m (Scullen; Bolinger) ; 8 mi NE Jacala (Fisher, E. M.) ; 8 mi SW Jacala , 1,645 m (Snelling, R. R.) ; Jalisco: [no specific locality] (Krauss, N. L. H.); 1 km S El Fresnito (Rifkind, J.) ; 10 km S Autlán , 1,600 m (Ward, P. S.) ; 4 mi W Mazamitla , 2,070 m (Smith, R. F.) ; 7 mi S Manzamitla (Leech, H. B.) ; Guadalajara (c.u.) ; Lagos de Moreno, Sta. Rosa , 1,900 m (Vásquez, M.) ; Mascota , El Atajo, km. 15 camino a San Sebastian del O., 1,200 m (Vásquez, M.) ; Mixtlán, Cerro Chato, Carr. Ameca-Mascota , km. 48, 1,780 m (Vásquez, M.) ; Mun. Autlán de Navarro, SSE Autlán , 1,435 m (MacDougal, J.) ; San Ignacio, Cerro Gordo , 2,200 m (Navarrete, J. L.) ; Tepatitlán, carretera a Arandas , 1,950 m (Vásquez, M.) ; Tequila, Volcán de Tequila , 1,435 m (Pérez, D.) ; Zapopan , Santa Lucia , 1,642 m (Vásquez, M.) ; México: Valle de Bravo (Parker, F. D.) ; Michoacán: 12.3 mi E Morelia , 2,165 m (Snelling, R. R.) ; 15–20 mi W Jiquilpan (Leech, H. B.) ; 3 mi E Carapan (Parker, F. D.; Stange, L. A.) ; 8 km E Quiroga , 2,285 m (Evans, H. E.) ; Cotija (Villegas, B.) ; Morelia (Krauss, N. L. H.) ; Pátzcuaro [as ‘Patzquero’] (Lipovsky, L. J.) ; Morelos: Chamilpa , 1,850 m (Quiroz, L.) ; Cuernavaca (Krauss, N. L. H.) ; Cuernavaca (Lipovsky, L. J.) ; Sto. Domingo , 1,900 m (Quiroz, L.) ; Tepotzlán (Olson, D. M.) ; Tlacotepec, Mpio. Zacualpan (Alemán, G.) ; Tlalnepantla , 2,030 m (Alemán, G.) ; Tres Marias [as ‘Tres Maria’] (Pereira, P.) ; Zacualpan , 1,730 m (Alemán, G.) ; Oaxaca: 12 mi SE Oaxaca , 1,630 m (Scullen; Bolinger) ; 5 mi SE Oaxaca , 1,875 m (Scullen; Bolinger) ; 9 mi SE Nochistlan (Janzen, D. H.) ; Monte Alban (Malkin, B.) ; Monte Alban (Vaurie, P.; Vaurie, C.) ; Oaxaca (Malkin, B.) ; Puebla: Cacaloapan (Parker, F. D.) ; km. 275, Hwy. 150, NE of Chapulco (Cornell Univ. Mexico Field Party) ; Tehuacán (Janzen, D. H.) ; Sinaloa: 1.6 km NNE El Palmito , 2,130 m (Ward, P. S.) ; 6 mi NE Potrerillos (Parker, F. D.; Stange, L. A.) ; Potrerillos (Schlinger, E.) ; Sonora: La Quintera (Timberlake) ; Santa Barbara , near Alamos , 1,450 m (Franklin, K. A.) ; Veracruz: Acultzingo nr. Orizaba (Janzen, D. H.) ; Huatusco (Quiroz, L.) .

Worker measurements (n = 13). HW 0.82–1.05, HL 1.02–1.28, MFC 0.033 –0.069, LHT 0.71–0.91, CI 0.80–0.87, FCI 0.040 –0.071, REL 0.38–0.44, REL2 0.46–0.55, FI 0.39–0.44, PLI 0.49–0.57, PWI 0.46–0.54, MSC 4–8.

Worker Diagnosis. Small to medium-sized species ( HW 0.82–1.05) with moderately elongate head ( CI 0.80–0.87) (Fig. 6) and relatively short eyes (see REL and REL2 values); frontal carinae separated by about basal scape width or less; metanotal groove present but weakly impressed; in profile, dorsal face of propodeum generally flat and more or less differentiated from declivitous face, rounding into the latter, and the two faces subequal in length; petiole moderately slender ( PLI 0.49–0.57, PL/HL 0.52–0.56); in profile petiole with slight or no anterior peduncle, the anterodorsal face flat to convex, ascending gradually to summit in posterior half of node, then rounding into more steeply descending posterior face; profemur slender; hind leg relatively short ( LHT /HL 0.69–0.75). Head opaque to subopaque, densely punctulate-coriarious, the punctulae on vertex usually separated by less than their diameters (but separated by more than their diameters in some populations, and the vertex correspondingly shinier). Standing pilosity sparse, absent from propodeum and mesonotum ( MSC 4–8). Gaster, metacoxa, metafemur and metatibia dark brown, contrasting with light orange-brown mesosoma; head, first and second pairs of legs, petiole, and postpetiole varying from dark brown (usually) to much lighter and concolorous with mesosoma.

Comments. The worker of this species is characterized by having a light-colored (orange-brown) mesosoma and contrasting dark gaster and hind leg. The head, other legs, petiole, and postpetiole also tend to be strongly infuscated, but in some samples (from Colima, Jalisco, and Chihuahua) they are lighter colored and even concolorous with the mesosoma. Workers of the closely related P. apache are uniformly orange-brown in color; see further discussion under that species. Pseudomyrmex championi has been confused with dark brown workers of a more distantly related species, P. cognatus , which occurs from southern Mexico to Nicaragua. The supposed descriptions of the larva ( Wheeler and Bailey 1920, Wheeler and Wheeler 1956) and queen ( Kempf 1961) of P. championi actually refer to P. cognatus . Workers of the two taxa can be distinguished as follows: P. championi is conspicuously bicolored, the dark gaster contrasting with the light orange-brown mesosoma, whereas P. cognatus is more uniformly dark brownish-black, with the mesosoma at most moderately lighter (and often dark on top); the metanotal groove is better developed (but still slight) in P. championi compared to P. cognatus ; and the eye is generally shorter in P. championi than P. cognatus ( REL 0.38–0.44 vs 0.43–0.48). The geographical distributions of P. championi and P. cognatus do not overlap ( Figs. 21 and 22 ) but because they belong to different species complexes in the P. elongatulus group (Fig. 1), they cannot be treated as allopatric variants of the same species.Their similarities must reflect convergence or shared ancestral features.

Distribution and Biology. Pseudomyrmex championi occurs in the Sierra Madre Occidental, Sierra Madre del Sur, and the intervening Transmexican Volcanic Belt ( Fig. 21 ). Collection labels with habitat and/or elevation information document the occurrence of this species in oak woodland, oak-pine forest, old field/pasture, mixed tropical/temperate mesic forest, mid-montane dry forest, and yucca desert, at elevations ranging from 1,200 m to 2,344 m (mean 1,828 m; n = 28). Four nests of P. championi encountered by one of us (P.S.W.) were all from dead twigs of woody shrubs (one Asteraceae , one Verbenaceae , and two unidentified plants).

Figures

Fig. 19–26. Pseudomyrmex elongatulus group: distribution maps. 19, P. apache; 20, P. arcanus (circles), P. fasciatus (triangles); 21, P. championi; 22, P. capillatus (triangles), P. cognatus (circles); 23, P. elongatulus (circles), probable introduced populations (stars); 24, P. comitator (square), P. ereptor (triangle), P. exoratus (circles); 25, P.salvini; 26, P. nimbus (circles), P. veracruzensis (triangle).