Azteca velox Forel,

Longino, J. T., 2007, A taxonomic review of the genus Azteca (Hymenoptera: Formicidae) in Costa Rica and a global revision of the aurita group., Zootaxa 1491, pp. 1-63: 50-52

publication ID

21311

publication LSID

lsid:zoobank.org:pub:C31A1226-724D-4D1A-8471-E6BB441EE3EF

persistent identifier

http://treatment.plazi.org/id/3D5E4B06-1A73-E833-E574-6A2AD7C1BE95

treatment provided by

Thomas

scientific name

Azteca velox Forel
status

 

Azteca velox Forel  HNS  1899

Figures 3,4A,5,6A,6B,7,6E,6F.

Azteca velox Forel  HNS  1899:108 [new name for Azteca coeruleipennis var. fasciata Pergande  HNS  1895, not Emery 1893]. Syntype workers: Mexico, Santiago Iscuintla (Eisen and Vaslit) [ NHMW, USNM]  (examined). Description of queen, male: Forel 1899:108.

Azteca velox var. nigriventris Forel  HNS  1899:109. Syntype workers, queens: Colombia, pied de la Sierra Nevada de Santa Marta, and San Antonio 1000 meters (Forel) [ MHNG]  (examined). Forel 1906:241. NEW SYNONYMY

Azteca velox var. rectinota Forel  HNS  1908a:61. Syntype workers: Costa Rica, Puntarenas (Biolley) [ MHNG]  (examined). NEW SYNONYMY

Queen characters. Measurements (n=11): HLA 1.72 (1.66-1.81), HW 1.72 (1.63-1.84), SL 1.06 (1.03-1.14, 10), CI 100 (98-103), SI 63 (60-65).

Palpal formula 6,4; ocelli small; middle and hind tibia with prominent pectinate apical spur; dorsal surface of mandible with small piligerous puncta, setae in puncta short, subdecumbent, interspaces between puncta shiny but faintly microareolate at base to weakly roughened near masticatory margin; medial and lateral clypeal lobes at about same level; head with convex sides, posterior margin not strongly cordate, very shallowly excavate; petiolar node tall, strongly compressed into thin scale at apex; posteroventral petiolar lobe evenly convex from front to back; scape with abundant erect setae, about as long as one half maximum width of scape; middle and hind tibia with abundant erect setae, longest of these about as long as one third maximum width of tibia (MTSC 15-30); sides of head without erect setae; posterior margin of head with erect setae; pronotum with erect setae on posterior margin; mesoscutum, scutellum, and propodeum with abundant erect setae; petiolar node rimmed with erect pubescence and sparse longer erect setae, 1-2 pairs of erect setae extending above apex in profile, posterior border of sternal lobe of petiole with dense layer of erect setae of irregular lengths; gastral terga with sparse long erect setae; light orange brown coloration on clypeus, malar area, antennal fossa, and side of head, variable extent of infuscation on medial and posterior vertex.

Worker characters. Measurements (n=7): HLA 0.98 (0.76-1.26), HW 0.99 (0.77-1.28), SL 0.82 (0.68- 1.01), CI 101 (97-102), SI 84 (78-89).

Palpal formula 6,4; middle and hind tibia with prominent pectinate apical spur; dorsal surface of mandible smooth and shining, with moderately abundant small piligerous puncta, setae in puncta short, erect, larger puncta with long setae near masticatory margin; medial and lateral clypeal lobes at about same level; head with convex sides, strongly cordate posterior margin; in lateral profile promesonotum forming single convexity; scape with abundant erect setae, length of setae about one half maximum width of scape; mid and hind tibia with abundant erect setae, longest setae about one half maximum width of tibia; side of head with about 5 erect setae on malar area, short erect setae variably present along entire side of head; posterior margin of head with abundant erect setae; pronotum, mesonotum, and dorsal face of propodeum with abundant long erect setae; anterior and anterolateral portions of head light yellow brown, variable extent of darker brown on medial vertex and posteriorly, mesosoma and gaster brown.

Similar species. Queens of A. quadricephala  HNS  have a more quadrate head shape and are less narrowed anteriorly (Fig. 6B). Queens of A. nigra  HNS  have a somewhat shorter head and the ventral petiolar lobe is deeper and ends before the posterior tergal lobe. Queens of A. flavigaster  HNS  have smaller heads (Fig. 6A).

Range. Mexico to Colombia and Venezuela.

Biology. Azteca velox  HNS  is a common species in a wide variety of habitats. It occurs most abundantly in seasonally dry areas, synanthropic habitats, and beach margins. Workers are common diurnal surface foragers. They are generalized scavengers and frequently visit extrafloral nectaries. The nests are polydomous, dispersed in multiple plant cavities. The cavities can be in live or dead stems. Colonies have also been associated with myrmecophytic orchids: Epidendrum bicornutum  in Costa Rica (Forel 1906) and Caularthron bilamellatum  in Panama (Fisher 1992). Colonies also develop, to variable extent, carton nests as extensions of nests in plant cavities.

In Santa Rosa National Park, Costa Rica, I observed several colonies. An incipient colony was in the hollow live stems of an understory shrub, Cassia hayesiana  (Fabaceae). The total stem length of the occupied space was about 1m, with inner cavity diameter of 0.5-1.0cm. There was one physogastric queen and no other reproductives. At two entrance sites they had built small globular carton dwellings, 2cm across and packed with workers and brood. The section of hollow stem near the queen was entirely plugged with a mass of eggs and young brood. The nest also contained a Microdon  (Syrphidae) puparium.

A second incipient colony was in a shaded Cordia alliodora tree  , a myrmecophyte usually occupied by Azteca pittieri  HNS  . A lone physogastric queen was in one of the internodes, and workers and brood were dispersed in other nodes of the tree. Some of the Cordia  nodes had small carton nests built on the surface.

In the forest at Santa Rosa I also observed a parabiotic association between Azteca velox  HNS  and Camponotus atriceps  HNS  . Workers of Azteca  HNS  and Camponotus  HNS  were running in and out of the same fissure in a tree trunk, showing no aggressiveness toward each other.

I observed a colony near Punta Quepos, at the edge of a small patch of degraded forest surrounded by pasture. About 4m of trailside had 10-20cm long carton nests scattered in the vegetation, on larger stems. I scraped one nest into a plastic bag -it contained a very high density of workers but no brood. A dead branch, in contrast, was packed with brood, males, and alate females. The dead branch was 3cm diameter with a 1- 1.5cm diameter continuous internal cavity. The ants had constructed rather regular perforated platforms inside the branch, every 1-1.5cm, making the inside look much like a Cecropia  branch interior.

Comments. Neither the morphological definition of this species nor the use of the name A. velox  HNS  are very well supported. The differences among A. sericeasur  HNS  , A. velox  HNS  , A. nigra  HNS  , A. quadraticeps  HNS  , and A. flavigaster  HNS  are subtle. I base the differences among the species mainly on the queens. The Azeca velox  HNS  queen is smaller than A. sericeasur  HNS  , larger than A. flavigaster  HNS  , with more rounded head than A. quadraticeps  HNS  , and longer head than A. nigra  HNS  . These conclusions are based on very small sample sizes of available queens. Workers of A. flavigaster  HNS  have a distinctive color pattern (contrasting yellow gaster and brown mesosoma), and the workers of A. quadraticeps  HNS  are unknown. The workers of A. sericeasur  HNS  , A. velox  HNS  , and A. nigra  HNS  are very similar. The largest workers of A. velox  HNS  and A. nigra  HNS  are always relatively small. In the field even large populous colonies are entirely composed of small workers. In contrast, populous colonies of A. sericeasur  HNS  (and A. instabilis  HNS  , which is hard to distinguish from this group in the field) have much larger workers in amongst the small workers. Azteca velox  HNS  and A. nigra  HNS  workers differ slightly in scape length, with A. velox  HNS  having proportionately shorter scapes. Azteca nigra  HNS  appears to be a wet forest version of A. velox  HNS  , having similar nesting behavior of using a combination of dead sticks and carton nests, but with much greater development of the carton nests into ant gardens.

The types of A. velox  HNS  are a few small workers from Mexico, collected in the late 1800's. They have erect setae on the posterior margin of the vertex, distinguishing them from A. sericea  HNS  , the size is small, separating them from A. sericeasur  HNS  , and the scapes are relatively short, separating them from A. nigra  HNS  . The fact that the species I am calling A. velox  HNS  is common in the open, seasonally dry habitats of Santa Rosa National Park, and Santa Rosa has many ant species that are widespread in similar habitats from there to southern Mexico, further strengthens the identity.

Forel (1899) discovered the Pergande homonym fasciata  HNS  and proposed the replacement name velox  HNS  . At the same time he described the queen and male, based on additional material from Costa Rica (Tonduz); Panama, Bugaba (Champion); and Colombia, pied de la Sierra Nevada de Santa Marta (Forel). It was not clear from which specimens he described the various castes. He noted that the species lived in hollow trunks, including fallen dead trees, and that it was uncertain whether carton construction was used for the nest. Some of this non-Pergande material has been incorrectly labeled as types and distributed to museums (MCZC, AMNH). The USNM, however, has true syntypes from Pergande's original collection (type #4481), in the type collection.

In the same paper Forel described the subspecies nigriventris  HNS  , based on his material from the Santa Marta region of Colombia. The syntypes included queens. I examined this material and it matched my concept of A. velox  HNS  . Forel (1906:241) later identified additional Costa Rican material as nigriventris  HNS  . This material was collected by Biolley in Esparza, from pseudobulbs of Epidendrum bicornutum  , with the note "in constant symbiosis." I examined this material and it matches my concept of A. velox  HNS  .

Additional material examined. COSTA RICA: Alajuela: R N. V. S. Cano Negro , 10°53'N, 83°12'W, 20m , 5- 28 Feb 1995 (K. F. Flores) - adult queen [ INBC]GoogleMaps  ; Guanacaste: Headquarters, Santa Rosa Nat. Park , 10°50'N, 85°37'W, 300m , 13 Jul 1985 (J. Longino) - workersGoogleMaps  ; Bosque Humedo, Santa Rosa Nat. Park , 10°51'N, 85°37'W, 300m , 12 Jul 1985 (J. Longino) - dealate queen, workersGoogleMaps  ; oak forest, Santa Rosa Nat. Park , 10°52'N, 85°36'W, 300m , 15 Jul 1985 (J. Longino) - dealate queen, workersGoogleMaps  ; Guacimo, Tempisque , 20 Jan 1937 (A. Alfaro) - worker [ USNM]  ; Playa Ostional , 9°59'N, 84°18'W, 5m , 13- 16 Jun 2004 (B. Gamboa, D. Briceño, M. Moraga, Y. Cárdenas) - queen [ INBC]GoogleMaps  ; Limón: Pto Viejo de Limon , 9°40'N, 82°45'W, 5m , 21 Mar 1987 (J. Longino) - workerGoogleMaps  ; Puntarenas: Sirena, Corcovado National Park , 8°29'N, 83°36'W, 5m , multiple dates and collections (J. Longino) - workers, malesGoogleMaps  ; Llorona, Corcovado National Park , 8°35'N, 83°42'W, 5m , 2 Jan 1982 and 21 Mar 1981 (J. Longino) - workersGoogleMaps  ; Manuel Antonio Nat. Park , 9°23'N, 84°09'W, 20m , 27- 28 Jul 1985 (J. Longino) - queen, workerGoogleMaps  ; Punta Quepos , 9°24'N, 84°10'W, 5m , 4 Jun 1989 (J. Longino) - queens, males, workersGoogleMaps  ; Rancho Quemado, Osa Peninsula , 8°42'N, 83°33'W, 200m , 15 Dec 1990 (J. Longino) - workersGoogleMaps  ; Golfito , 8°39'N, 83°09'W, 50m , 15 Aug 1957 (A. Menke) - dealate queen [ LACM]GoogleMaps  ; same locality, Jan 1999 (P. Hanson) - workerGoogleMaps  ; Esparza , Feb 1905 (Biolley) - alate queens, workers [ MHNG]  ; Curu Wildlife Refuge , 9°47'N, 84°55'W, 5m , 28 Mar 1993 (J. Longino) - workerGoogleMaps  ; PANAMA: Canal Zone: Barro Colorado Island , 9°09'N, 79°51'W, 100m , 5 Apr 1987 (B. Fisher) - queen, male, worker [ LACM]GoogleMaps  ; VENEZUELA: Aragua: Rancho Grande , 10°21'N, 67°41'W, 1100m , 1945 (W. Beebe) - dealate queen [ LACM]GoogleMaps  .

NHMW

Austria, Wien, Naturhistorisches Museum Wien

USNM

USA, Washington D.C., National Museum of Natural History, [formerly, United States National Museum]

MHNG

Switzerland, Geneva, Museum d'Histoire Naturelle

INBC

Costa Rica, Santo Domingo de Heredia, Instituto Nacional de Biodiversidad (INBio)

LACM

USA, California, Los Angeles, Los Angeles County Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Formicidae

Genus

Azteca