Temnothorax longispinosus

A well studied North American ant species.

Identification
Mackay (2000) - A member of the ''Temnothorax longispinosus species complex. This is a small, brown species with an 11-segmented antenna and with very well developed propodeal spines. The spines are nearly twice the length of the distance between their bases, and are in about the same plane as the remainder of the mesosoma. The head is nearly mostly smooth and glossy, but with fine striolae.

The long propodeal spines easily separate this species from most of the others in the subgenus. It can be separated from Temnothorax ambiguus and Temnothorax curvispinosus, which also have long propodeal spines, by the nearly glossy head and by the much darker color. The propodeal spines are nearly in the same plane as the mesosoma, which separates it from Temnothorax tuscaloosae (in which the spines are pointed somewhat upwards). The top of the mesosoma is roughly sculptured, whereas the top of the mesosoma of T. tuscaloosae is smooth.

Distribution
USA, CANADA: Minnesota. Wisconsin. Iowa. Missouri, Illinois, Michigan. Indiana. Kentucky. Tennessee. Alabama. Ohio. Maine. New York. Vermont, New Hampshire, Massachusetts, Connecticut, Pennsylvania. New Jersey. Maryland. Washington D. C.. West Virginia. Virginia, North Carolina. South Carolina. Georgia; Canada: Quebec, Ontario. (Mackay 2000)

Distribution based on Regional Taxon Lists
Nearctic Region: Canada, United States. Palaearctic Region: Iberian Peninsula, Spain.

Abundance
Common.

Biology
Mackay (2000) - This species nests in plant cavities such as hollow stems, twigs, and in acorns (Headley, 1943), as well as under stones (Wheeler, 1905; Cole, 1940) and between clefts in rocks, in stone walls or under bark (Wheeler, 1903a), including dead, standing trees (Dennis, 1938), or within rotting logs (Cole, 1940). Nests may be small, one nest was 1.2cm deep under a pebble with a diameter of 0.6cms (Cole, 1940). It is found in conifer forests (Letendre and Pilon, 1972) or mixed species forests, where shade of trees is dense (Dennis, 1938; Headley, 1943; Carter, 1962), or prefers open areas with good drainage (Herbers, 1985). It is found occasionally at lower elevations in the southern Blue Ridge ofVirginia (Van Pelt, 1963). Nest populations are relatively larger than in other species (Wheeler, 1903a), and average 46 workers, to a total (including sexuals and brood) average of 136 and a maximum of 419 (Headley, 1943). Egg laying begins in mid May, but brood are present in the nest through the year (Headley, 1943). Pupae are present in the nest by the second week of June (Headley, 1943). Worker populations peak late in the season (Headley, 1943). Winged females and males are found in nests in August (Wheeler, 1903a). Workers reproduce in queenright colonies (Frumhoff and Ward, 1992). They are polygynous (Alloway et al., 1982; Herbers, 1984; 1986a) and polydomous (Alloway et al., 1982; Herbers and Tucker, 1986) with many nests found without queens (Headley, 1943). Scarcity of available nest sites may influence the pattern of polygyny (Herbers, 1986b). This species spreads by nest fission and migration (Herbers and Tucker, 1986a). Mating flights occur from mid July until early September (Leprince and Francoeur, 1986), with mating occurring on hilltops. Females are inseminated once, or use sperm from a single male for a given clutch (Herbers, 1986c). Nests are considerably more spread out in the summer than they are in the winter (Herbers, 1985). Apparently nests fractionate in the summer to occupy several nest sites (Herbers, 1986a). Many summer nests are queenless, whereas such nests are rarely found in the winter (Herbers 1986a), and survivorship of nests during the winter may be a function of the resident queen number (Herbers 1986b). Nest density can be as high as 1.7 (Headley, 1943) to 4 (Herbers, 1985) nests per square meter. This species forages on the low vegetation in the shade of trees (Wheeler, 1903a, 1905). Foraging activity peaks in summer and fall (Herbers, 1989). Herbers (1990) and Backus (1993) reported on the investment of this ant in workers and rcproductives. Social organization was discussed by Herbers (1983).

Colony Attributes
Colonies typically contain less than one hundred workers although an occasional nest can be found that exceeds this number. Roughly half of the queens survive the winter, for workers roughly two thirds to slightly more than one half survive from fall to spring. (Herbers, her co-workers and others).

Nesting Biology
Nests are located in preformed cavities in structures found in the litter, e.g., in small sticks or nuts. Temnothorax longispinosus is facultatively polydomous and their nesting arrangements vary with season. In the productive summer months, colonies can fragment and be arranged across numerous nest sites. These vary in queen number, from multiple queens to those that only have workers and brood.

During the winter nests coalesce and typically are found in a single structure. In northeastern hardwoods forests this will typically be a nut (acorn, hickory) or small twig in the leaf litter. Nest mortality can be significant. From one third to one half of all nests are gone by the end of the winter. Some of these losses are colony deaths while others represent migration to a new nest site, which likely occurs during warmer winter days. (based, in part, on Herbers and Johnson 2007, Herbers 1989, Alloway 1983)

Reproduction
Queen number can vary by colony and season. New colonies are founded by pleoemetrosis and new queens are likely adopted into existing nests. The latter is evident from the presence within populations of both monogynous and polygonous nests. Reproductive queens contain 7 ovarioles.

Worker reproduction does occur with some male production possible from worker derived eggs. Reproductive workers contain 2 ovarioles.

New queens are produced in some queenless nests. These are presumed to be nests that are separated from a queenright nests or from a nest that had earlier lost its queen(s). (based, in part, on Herbers and Johnson 2007, Alloway 1983)

Kannowski (1959) noted the following concerning Temnothorax longispinosus reproduction: "Headley (1943b) in a population analysis of this species in a woods in northern Ohio, found alates in nests on July 12 and August 16, 1942. The single record of alates in the bogs came on August 12, indicating that the period of alate occurrence in southern Michigan bogs may be slightly later than for upland communities in Ohio.

Other Ants
This species is parasitized by three species of slave-making ants:, and  (Headley, 1943; Alloway et al., 1982; Alloway and del Rio Pesado, 1983; Alloway and Keough, 1990, Beibl et al. 2005, [[Media:Seifert, B., Kleeberg, I. et al. 2014. Temnothorax pilagens sp. n. - a new slave-making species of the tribe Formicoxenini from North America.pdf|Seifert et al. 2014]]). It can recognize Temnothorax americanus as an enemy (Alloway, 1990).

Nomenclature

 *  longispinosus. Leptothorax longispinosus Roger, 1863a: 180 (w.) U.S.A. Emery, 1895c: 321 (q.); Wheeler, W.M. 1903c: 238 (m.); Crozier, 1970: 117 (k.); Wheeler, G.C. & Wheeler, J. 1989a: 323 (l.). Combination in L. (Myrafant): Smith, M.R. 1950: 30; in Temnothorax: Bolton, 2003: 271. Senior synonym of iowensis: Creighton, 1950a: 264. See also: Mackay, 2000: 358.
 * laeviceps. Leptothorax (Leptothorax) longispinosus subsp. laeviceps Buren, 1944a: 287 (w.) U.S.A. [Junior primary homonym of leviceps Emery, 1898c: 134.] Replacement name: iowensis Buren, 1945: 288.
 * iowensis. Leptothorax longispinosus subsp. iowensis Buren, 1945: 288. Replacement name for laeviceps Buren, 1944a: 287. [Junior primary homonym of leviceps Emery, 1898c: 134.] Junior synonym of longispinosus: Creighton, 1950a: 264.

Type Material
United States. Mackay (2000) - None in this country (Creighton, 1950), and the types could not be located in Roger's collection (Museum fur Naturkunde Zentralinstitut der Humboldt Universitat zu Berlin) and probably no longer exist.

Worker
2.5 mm. lang. Mittelgrofsen Stucken des L. angusiulus sehr ahnlich (die grofsten Exemplare lelzterer Art messen 3-8 Mm.), ebenfalls sebwarzbraun, glanzend, mit ben gelblichbraunen Mandibeln, Fublern,Gelenken, Schienen und Tarsen. Die abstehenden Harchen sind sparlich und keuleoformig.Die Fuhler sind eilfgliedrig. Der Kopf ist vorn langs-, seitlich elwas verworren gerunzelt, hinten glatt; der Thorax ist unregelmafsig langs gerunzelt. Ein Eindruck zwischen Meso- und Metanotum ist nur schwach angedeutet. Die Enddornen des Letzieren sind sehr lang, viel linger als bei angusiulus, nach hinten gerichtet und leicht bogeoformig gekrummi. Die Knoten sind. verworren gerunzelt, an der Unterseite des ersten sitzt vern ein Zahnehen.

(Wheeler 1903) Length 2.25-2.5 mm. Head exclusive of the mandibles not much longer than broad,posterior angles considerably rounded. Mandibles ,5-toothed. Eyes of moderate size, rather flattened. Clypeus convex, not impressed in the middle, its anterior border rounded. Antennae 11-jointed, scape reaching the posterior angle of the head, club 3-jointed; first funicular joint as long as joints 2-4 together; joints 1-3 broader than long; joints 4-6 as long as broad; terminal joint as long as the two preceding joints together. Thorax rather short, anterior angles rounded but distinct, dorsal surface and pleural somewhat flattened; mesoepinotal suture distinct but without a constriction. Epinotal spines very long and stout, directed backward, rather suddenly tapering at their tips which are curved slightly inward and downward. Petiole from above suboblong, twice as long as broad, sides nearly parallel, posterior border a little broader than the anterior; in profile the anterior slope is distinctly and evenly concave, the posterior convex; the anterior ventral surface has a distinct but rather blunt tooth; summit of node blunt. Postpetiole hardly half again as broad as the petiole, as long as broad, with rounded but distinct anterior angles, convex dorsally. Gaster of the usual shape, with distinct anterior angles.

Mandibles coarsely longitudinally rugose, hardly shining. Clypeus somewhat shining, traversed even in the middle by several clean-cut longitudinal rugre. Head shining, especially on the posterior and postero-lateral portions; anteriorly with clean-cut longitudinal rugal, which are coarsely reticulate and further apart on the cheeks, more delicate on the crown and occiput. Thorax opaque, except the mesonotum, which is somewhat shining. Neck coarsely and evenly punctate; remaining surface of thorax covered with coarse, irregularly longitudinal rugre which extend up on the epinotal spines; interrugal spaces with shallow foveolate punctures, forming a secondary reticulation. Petiole and postpetiole opaque, coarsely rugose and punctate. Gaster very smooth and shining.

Hairs silvery-white, those on the head, thorax and abdomen very regularly arranged, clavate, erect; on the antennre and legs minute, nonclavate and appressed.

Head and gaster black; thorax and pedicel dark-brown; antennae and legs yellow; scape and club of the former, coxre, femora and sometimes also the tibial of the latter, infuscated. Mandibles dark-brown, their distal half yellow.

(Wheeler 1903) Length 3.5-4 mm. Head opaque, densely and rather finely longitudinally rugose. Eyes moderate; ocelli rather small. Thorax opaque; pronotum coarsely longitudinally rugose; mesonotum traversed by numerous very regular, parallel rugre. Scutellum somewhat shining, covered with much more delicate rugae than those of the mesonotuill and more reticulate and less longitudinal in direction. Pleurae, epinotum and epinotal spines covered with coarse reticulate rugal, which have a decidedly longitudinal trend. Epinotal spines shorter, stouter and less curved than those of the worker. Petiole and postpetiole opaque and more roughly sculptured than those of the worker. Wings milky-white, the veins and stigma very pale. Pilosity and color of body, legs and antennae like the worker, except that the thorax is darker and often quite black, especially on the dorsal surface

Male
(Wheeler 1903) Length 2-2.5 'mm. Head, exclusive of the. mandibles, about as broad as long. Eyes very prominent; ocelli reniform. Mandibles overlapping, small, acute, dentate. Antennae 12-jointed; scape as long as joints 1-4 of the funiculus, the funiculus with a 4-jointed club; first funicular joint swollen, somewhat longer than joints 2-3 together; joints 3-7 cylindrical, about twice as long as broad, joints of club fusiform gradually increasing in length distally. Thorax with strongly marked parapsidal and Mayrian furrows. Epinotum evenly rounded, with two small prominences in the place of the large spines of the worker and queen. Petiole larger and postpetiole more slender than in the worker and both with much lower nodes, the former somewhat pedunculate, the latter subquadrate from above, with rounded angles, as long as broad and hardly half again as broad as the petiole. Gaster of the usual shape. Legs rather long and slender.

Clypeus shining, with a few clean-cut, longitudinal rugae. Head subopaque, indistinctly rugose and punctate except the cheeks, where the rugae are pronounced and reticulate. Thorax smooth; pleurae, mesonotum and scutellum shining, their surfaces indistinctly and irregularly punctate at the sutures. Epinotunl opaque; very finely rugose. Petiole and postpetiole opaque, finely rugose; the upper surfaces of the nodes, especially of the postpetiole, smooth and almost shining. Gaster subopaque.

Hairs on the body few and very slender, whitish; longest on the gaster; those on the legs and antennre minute and appressed. Black; mandibles, antennre, legs and genitalia white. Bases of mandibles, scape, antennal club, coxae, femora, tibiae and last tarsal joint of each foot, distinctly infuscated. Wings milky-white with very pale veins and stigma.

Etymology
Morphological. Reference to the long spines (for a Temnothorax species) on the propodeum.