Temnothorax hispidus

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Temnothorax hispidus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Temnothorax
Species group: sallei
Species: T. hispidus
Binomial name
Temnothorax hispidus
(Cole, 1957)

Temnothorax hispidus casent0105861 profile 1.jpg

Temnothorax hispidus casent0105861 dorsal 1.jpg

Cole (1957): "The holotype and large series of paratypic workers, together with three paratypic nest queens, were collected by the writer, on June 11, 1956, from six nests at an elevation of approximately 5,400 ft. in Limpia Canyon, Davis Mts., Texas. Each shallow nest was in moist, loamy soil beneath a stone in a low, shaded, grassy and sparsely-wooded area. The station, which was entirely surrounded by arid slopes, was only of about 100 square yards in area and represented a rather distinctive ecologic unit."

From the Chiso Mountains, also in Texas, Van Pelt (1983) reports the species nests under rocks or in soil at higher elevations.

Identification

Mackay (2000) - A member of the Temnothorax hispidus species complex. This is a large species (3-4 mm total length) with a 12 segmented antenna, dark brown, with the mesosoma depressed at the area of the mesopropodeal suture, although the sculpture is not broken in the region. The top and side of the mesosoma are covered by coarse, reticulated rugae. The propodeal armature is represented by bumps. The node of the petiole is low and truncate. The petiole and postpetiole are covered with reticulated rugae.

The strongly reticulo-punctate disc of the first gastral tergite, the depressed mesosoma, and the large size will separate this species from all other species in the subgenus, including the other species in the hispidus complex (Temnothorax peninsularis, Temnothorax punctaticeps). Cole (1957) stated that this species is most closely related to Temnothorax silvestrii I cannot agree as the only important characteristic they have in common is that the disc of the gastral tergum is distinctly reticulopunctate (which appears to have evolved independently several times), and this characteristic varies considerably, at least in Temnothorax silvestrii. It can be easily distinguished from Temnothorax silvestrii, as the hind femur in Temnothorax silvestriii is greatly incrassate, which is not the case in Temnothorax hispidus. In addition, the impression at the mesopropodeal suture is absent in Temnothorax silvestrii; the scapes are longer in Temnothorax hispidus, as compared to Temnothorax silvestrii. The eye is normal in shape for the genus, which easily separates this species from Temnothorax obliquicanthus, which has a kidney-shaped eye. In addition the propodeal spines are simple angles in Temnothorax hispidus and are well developed in the other two species. Although this is clearly a member of the subgenus Myrafant, it does show possible affinities to the subgenus Dichothorax. The anterior peduncle of the petiole is relatively long, there is a distinct impression at the mesopropodeal suture, and the propodeal spines are short. This species also has a relatively long antennal scape. These characteristics justify placing this species in its own complex, together with Temnothorax peninsularis and Temnothorax punctaticeps. This species appears to be similar to the Palaearctic Temnothorax schaufussi, which also appears to be related to Temnothorax pergandei(Mackay, 1993a). Both have long antennal scapes, elongate mesosomae, and relatively long petiolar peduncles, although that of Temnothorax hispidus is much less developed. The mesopropodeal suture is deeply depressed on the dorsum of the mesosoma of both species. Nevertheless these two species are easily separated as Temnothorax hispidus is roughly sculptured, with rugae on the head, mesosoma and dorsum of the postpetiole, whereas at least the head and pronotum of Temnothorax schaufussi is smooth and polished. As mentioned above, the peduncle of Temnothorax schaufussi is elongate, that of Temnothorax hispidus is much shorter. It is tempting to consider Temnothorax hispidus as a member of the subgenus Dichothorax, but it appears to belong to Myrafant, with Temnothorax schaufussi and Temnothorax pergandei belonging in the subgenus Dichothorax. Temnothorax hispidus appears to link the two subgenera."

Keys including this Species

Distribution

USA. Texas. Mexico. Coahuila, Nuevo Leon, Zacatecas.


Latitudinal Distribution Pattern

Latitudinal Range: 34.156971° to 25.74013°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).
Neotropical Region: Mexico.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Habitat

Pinyon (Chiso Mts) and grassy, sparsely wooded area in the Davis Mts.

Abundance

Only known from a few collections.

Biology

Not much is known about the the biology of Temnothorax hispidus. We can speculate that the biology of this species is likely to be similar to other North American species of this genus.

Temnothorax is a diverse genus but most species do show a remarkable consistency in some important aspects of their biology. Workers and colonies are small. As a group they nest in many places: small cavities in the soil, under or among stones or in small cavities in living or dead vegetation. Individually, most species have a strong preference for how and where they nest, e.g., there are gall nesting species, soil nesters, arboreal species, those that nest in small downed twigs, etc. Their nest entrances are often a cryptic, tiny hole that is only found by observing a worker exiting or entering the nest. A few common and abundant species are relatively well studied but the majority are rare or are rarely collected. For all but the most common and abundant species finding a nest is difficult because of the combination of their small colony size, small workers, unaggressive behavior, and diminutive, inconspicuous nests. In a few cases where we do know the diet of a species, it consists of sweet exudates and general scavenging of insect pieces and other items. It is presumed most of the unstudied Temnothorax have a similar diet. Aphid tending and hunting small soil arthropods may also be a part of their foraging repertoire. For all the consistency in these characters, individual species exhibit wide variation in others. Habitat affinities are often restrictive at the species level (but overall Temnothorax can be found in places that range from high elevation, high latitude, forests to hot, dry desert regions). Queen number is difficult to predict; there are species that are polygnous, monogynous, and even some species with seasonal polydomy that vary in nesting site queen number over the course of the year. There is also little consistency in color from species to species.

Castes

Worker

Queen

Male

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • hispidus. Leptothorax (Leptothorax) hispidus Cole, 1957b: 42, fig. 1 (w.q.) U.S.A. Wheeler, G.C. & Wheeler, J. 1973b: 71 (l.). Combination in L. (Myrafant): Smith, D.R. 1979: 1393; in Temnothorax: Bolton, 2003: 271. See also: Mackay, 2000: 347.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Holotype, worker (Cole Coil. No. TX-52).

Head length, from anterior clypeal border to median occipital border, 0.92 mm.; head width, just behino eyes, 0.77 mm.; scape length, 0.82 mm.; thoracic length, 1.36 mm.; pronotal width, 0.56 mm.; petiolar length, including peduncles, 0.39 mm.; width of petiolar node, 0.22 mm.; length of postpetiolar node, 0.27 mm.; width of postpetiolar node, 0.34 mm.; overall body length, 4.30 mm.

Head broader behind than in front, broadest just behind the eyes; sides subparallel; occipital border and corners broadly and evenly convex. Median lobe of clypeus subtriangular, not prominently convex, the anterior border broadly but not deeply emarginate. Frontal lobes broad, thin, with rather evenly rounded lateral border, not projecting upward. Frontal area subrectangular. Antennae with 12 segments, the terminal three forming a distinct club; scape robust, its tip reaching the occipital border. Eyes prominent, convex.

Thorax, viewed from above, with a very faint but distinct mesoepinotal suture; viewed in profile, the dorsum somewhat flattened, but broadly and faintly concave in the region of the mesoepinotal suture. Epinotal spines very short, dentiform. Petiole, in profile, with a node which descends gradually, evenly, and slightly concavely to the anterior peduncle, and slopes convexly posteriorly to the short and steep posterior declivity; anterior portion higher than posterior one; anterior peduncle with a small, distinct, triangular, ventral tooth; posterior peduncle thick and short. Postpetiole, in profile, with a rather abruptly ascending anterior face and a broadly convex crest. Viewed from above, the petiole, including its peduncles, is about twice as long as broad at its widest part, the node subovate. Postpetiole, viewed from above, about 1 1/2 times as broad as the petiole, subcuboidal. Femora moderately incrassate. Gaster elliptical, truncate anteriorly.

Head (except clypeus and mandibles), thorax, petiole, and postpetiole moderately strongly rugulose and weakly reticulose, the interspaces densely and finely granulose and rather shining; between eyes and antennal sockets are coarser, widely-spaced, parallel rugae. Mandibles longitudinally striate and shining; clypeus longitudinally rugulose, the interspaces smooth and shining. Antennal scapes striato-granulose and dull; legs finely coriaceous and shining. Thoracic dorsum densely granulose and longitudinally rugulose, the rugulae fine and rather faint through median portion of pronotum, much coarser on base of epinotum; epinotal declivity transversely striatogranulose and much more shining. Dorsum of petiolar and postpetiolar nodes densely and coarsely granulose, the lateral surfaces of the nodes with a few irregular rugulae which have a longitudinal trend. Sides of thorax granulose, weakly reticulose and more strongly rugulose, especially on the prothorax where the rugae are gently and evenly curved upward; the rugulae become notably reticulose on the sides of the meso thorax and become transverse on the sides of the posterior portion of the epinotum, just behind the spiracles, where they extend to the epinotal declivity. Dorsum of first gastric segment finely striolate and densely and finely coriaceous, most obviously so near the base.

Dorsum of entire body with very abundant, stout, blunt, silvery, erect hairs which are shortest on the head, longer (but variable in length) on thorax, petiole, postpetiole, and gaster, and which give a brush-like appearance to the body. Hairs abundant, erect and suberect on scapes; numerous, suberect and appressed on funiculi which have a dense, rather long, and silvery pubescence. The legs and the venter of the head, thorax, and gaster with the hairs abundant but pointed and more delicate. Eyes with numerous very short hairs. Hairs sparse on venter of postpetiole and absent from venter of petiole. Hairs on dorsum of petiole, postpetiole, and gaster somewhat reclinate.

Color of vertex and frons of head and of thorax, petiole, postpetiole, and appendages a very deep reddish brown; gaster somewhat darker. Remainder of head (including mandibles and entire venter) as well as the pronotal collar a light reddish brown.

Queen

Paratype-nest queen (Cole Coll. No. TX-52).

Head length, 1.00 mm.; head width (just behind the eyes), 0.95 mm.;scape length, 0.87 mm.; thoracic length, 2.04 mm.; petiolar length, 0.56 mm.; width of petiolar node, 0.34 mm.; postpetiolar length, 0.36 mm.; width of postpetiolar node, 0.46 mm.; overall body length, 6.09 mm.

Head subquadrate, no wider behind than in front of eyes; occipital border broadly and evenly rounded; sides subparallel. Eyes strongly convex. Ocelli prominent. Antennal scapes in repose extend nearly to the occipital margin. Other cephalic characteristics like those of holotype.

Viewed in profile, scutum nearly flat, separated from the broadly convex scutum by a distinct impression. Basal and declivious faces of epinotum subequal in length. Epinotal spines very short, dentiform, very broad basally, acute apically. Petiolar node with the rather steeply sloping anterior face broadly and slightly concave, evenly rounded apically and sloping gradually posteriorly to the lower part of the declivity which descends abruptly to the peduncle. Postpetiole like that of holotype. Thorax, viewed from above, notably broader than head, the widest part being at the tegulae posteriorly from which the thorax narrows evenly to the epinotal declivity. Epinotal spines joined at their bases by an even, broadly concave surface. Petiole broadest across its node, subpyriform in outline; postpetiole transversely subrectangular.

Gaster broadly elliptical, truncate basally.

Cephalic and thoracic sculpture, as well as that of petiole and postpetiole, similar to that of worker, but interrugal granulation is faint and the surface is more shining. Entire scutum covered with coarse, widely space, piligerous punctures. Dorsum of first gastric segment with long, straight, fine, closely-spaced, longitudinal striae which are more dense in the basal third, become less obvious in the median third, and fade out in the distal third. These striae notably dull the otherwise shining surface.

Pilosity like that of the holotype, except less coarse, slightly more abundant, and in general less blunt. Eyes bear several short hairs.

Color similar to that of the holotype, but posterior portion of head paler, and hence does not contrast so sharply with the anterior portion, and anterior part of thorax lighter than that of holotype.

Male

Males have been collected but this caste is undescribed.

Type Material

Mackay (2000) - USA, TX, Jeff Davis Co., Davis Mountains, Limpia Canyon, 5,400' "Holotype worker in Cole collection, paratypes in Cole collection (University of Tennessee), Kennedy collection (Ohio State University), Creighton collection, Gregg collection (Colorado State University), Talbot collection (Lindenwood College), American Museum of Natural History, Museum of Comparative Zoology, National Museum of Natural History [seen]."

References

References based on Global Ant Biodiversity Informatics

  • Cole A. C., Jr. 1957. A new Leptothorax from Texas (Hymenoptera: Formicidae). Journal of the Tennessee Academy of Science 32: 42-45.
  • Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
  • Mackay W. P. 2000. A review of the New World ants of the subgenus Myrafant, (genus Leptothorax) (Hymenoptera: Formicidae). Sociobiology 36: 265-444.
  • O'Keefe S. T., J. L. Cook, T. Dudek, D. F. Wunneburger, M. D. Guzman, R. N. Coulson, and S. B. Vinson. 2000. The Distribution of Texas Ants. The Southwestern Entomologist 22: 1-92.
  • Van Pelt, A. 1983. Ants of the Chisos Mountains, Texas (Hymenoptera: Formicidae) . Southwestern Naturalist 28:137-142.
  • Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133