Dorymyrmex

All species of Dorymyrmex are ground nesting and usually occur in drier habitats, especially grasslands. Nests are often in open areas without covering, and entrances are surmounted by an irregular mound of loose soil.

Identification
Shattuck (1992) - Worker: Angle of propodeum with a single medial dorsal spine or tooth; psammophore present, weakly to strongly developed; third maxillary palp segment elongate, subequal in length to segments 4+5+6; anterior clypeus margin with numerous elongate, curved hairs which extend beyond (rarely just to) the distal edge of closed mandibles; apical tooth of mandibles greatly elongate. North and South America.

Queen: Anterior clypeal margin with long, strongly ventrally curved setae which surpass the distal edge of closed mandibles; psammophore present; third maxillary palp segment elongate and subequal to or longer than the combined lengths of segments 4+5+6.

Male: Third maxillary palp segment longer than the combined lengths of segments 4+5; anterior clypeal margin with moderately ventrally curved setae; second funicular segment with a lateral bend; pygostyles reduced; mandibles with 2 to 3 teeth and 2 denticles.

Workers of Dorymyrmex are at once identifiable by the presence of a psammophore (sometimes reduced, but always present), an elongate third palp segment, and the development of a tooth or spine at the propodeal angle.

Cuezzo and Guerrero (2011) - Major characters differing among worker, queen, and male of Dorymyrmex and Forelius.

Nomenclature

 *  DORYMYRMEX [Dolichoderinae: Leptomyrmecini]
 * Dorymyrmex Mayr, 1866a: 494. Type-species: Dorymyrmex flavescens, by monotypy.
 * Dorymyrmex senior synonym of Psammomyrma: Forel, 1913b: 350 (in text); Santschi, 1922b: 365; Snelling, R.R. & Hunt, 1976: 93; Shattuck, 1992c: 77.
 * Dorymyrmex senior synonym of Spinomyrma: Snelling, R.R. & Hunt, 1976: 93; Shattuck, 1992c: 77.
 * Dorymyrmex senior synonym of Conomyrma (and its junior synonyms Biconomyrma and Araucomyrmex {and its junior synonym Ammomyrma}): Shattuck, 1992c: 77.
 * AMMOMYRMA [junior synonym of Dorymyrmex]
 * Ammomyrma Santschi, 1922b: 365 [as subgenus of Dorymyrmex]. Type-species: Dorymyrmex exsanguis, by original designation.
 * Ammomyrma junior synonym of Araucomyrmex: Snelling, R.R. & Hunt, 1976: 93.
 * Ammomyrma junior synonym of Dorymyrmex: Shattuck, 1992c: 77.
 * ARAUCOMYRMEX [junior synonym of Dorymyrmex]
 * Araucomyrmex Gallardo, 1919b: 249. Type-species: Dorymyrmex tener, by original designation.
 * Araucomyrmex subgenus of Dorymyrmex: Santschi, 1922b: 365; Kusnezov, 1952g: 428.
 * Araucomyrmex revived status as genus: Kusnezov, 1956: 28; Kusnezov, 1959: 51.
 * Araucomyrmex senior synonym of Ammomyrma: Snelling, R.R. & Hunt, 1976: 93.
 * Araucomyrmex junior synonym of Conomyrma: Snelling, R.R. 1981: 402.
 * Araucomyrmex junior synonym of Dorymyrmex: Shattuck, 1992c: 77.
 * BICONOMYRMA [junior synonym of Dorymyrmex]
 * Biconomyrma Kusnezov, 1952g: 429 [as subgenus of Conomyrma]. Type-species: Dorymyrmex pyramicus var. brunneus (now Dorymyrmex brunneus), by subsequent designation of Kusnezov, 1959: 51.
 * Biconomyrma raised to genus: Kusnezov, 1959: 51; Kusnezov, 1964: 67.
 * Biconomyrma junior synonym of Conomyrma: Smith, M.R. 1958c: 140; Kempf, 1972a: 78.
 * Biconomyrma junior synonym of Dorymyrmex: Shattuck, 1992c: 78.
 * CONOMYRMA [junior synonym of Dorymyrmex]
 * Conomyrma Forel, 1913b: 350 (in text) [as subgenus of Dorymyrmex]. Type-species: Prenolepis pyramica, by subsequent designation of Santschi, 1922b: 365.
 * Conomyrma raised to genus: Kusnezov, 1952g: 429.
 * Conomyrma senior synonym of Biconomyrma: Smith, M.R. 1958c: 140.
 * Conomyrma senior synonym of Araucomyrmex: Snelling, R.R. 1981: 402.
 * Conomyrma junior synonym of Dorymyrmex: Shattuck, 1992c: 77.
 * PSAMMOMYRMA [junior synonym of Dorymyrmex]
 * Psammomyrma Forel, 1912h: 43 [as subgenus of Dorymyrmex]. Type-species: Dorymyrmex planidens, by subsequent designation of Wheeler, W.M. 1913a: 82.
 * Psammomyrma subgenus of Dorymyrmex: Kempf, 1972a: 100.
 * Psammomyrma junior synonym of Dorymyrmex: Forel, 1913b: 350; Santschi, 1922b: 365; Snelling, R.R. & Hunt, 1976: 93.
 * SPINOMYRMA [junior synonym of Dorymyrmex]
 * Spinomyrma Kusnezov, 1952g: 429 (diagnosis in key) [as subgenus of Dorymyrmex]. Type-species: Dorymyrmex alboniger, by subsequent designation of Kusnezov, 1959: 51.
 * Spinomyrma raised to genus: Kusnezov, 1956: 30 (in key); Kusnezov, 1959: 51.
 * Spinomyrma subgenus of Dorymyrmex: Kempf, 1972a: 100.
 * Spinomyrma junior synonym of Dorymyrmex: Snelling, R.R. & Hunt, 1976: 93.

Taxonomic Notes
The species-level taxonomy of the North America species of this genus is poorly understood. Wheeler (1902) and most subsequent authors failed to appreciate the fact that there are a number of entirely blackish species in the United States, referring to them all as "D. pyramicus". As a result, much of the literature on "D. pyramicus" in North America is unreliable as there is little certainty as to the identity of the ant involved in each case. While most records from west of the Continental Divide may apply to D. insanus, those from east of the Mississippi River almost certainly do not.

Description
Shattuck (1992):

Worker
HEAD. Vertex convex to weakly concave. Compound eyes present, approximately round; relatively anterior on head. Ocelli absent. Antennae 12 segmented. Scape relatively short, at most surpassing the vertex by less than one-half (often less than one-third) its length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae 4-12; long and surpassing the distal edge ofthe closed mandibles; strongly curved ventrally. Posterior clypeal margin between the anterior and posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Frontal carina present. Anterolateral hypostoma reduced to a thin sclerite (extending past the mandibular insertion in some South American species, but always thin). Medial hypostoma entire. Psammophore present (originating at extreme lateral edges of head or 'V"shaped and placed medially on under surface of head, and weakly to strongly developed). MOUTHPARTS. Palp formula 6:4 (distal 3rd and entire 4th maxillary segment sometimes flattened and expanded). Third maxillary palp segment subequal to or longer than the combined lengths of segments 4+5+6. Fifth maxillary palp segment at the apical extreme of segment 4, or subapical and with a finger- like extension distal of the attachment point. Mandible with 6-7 teeth and 0-1 denticles. Apical tooth elongate and much longer than the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin varying from smooth (without teeth or denticles) to denticulate along entire surface. MESOSOMA. Posteroventral pronotum lateral, rounded orangled. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Declivitous face of propodeum convex to weakly concave; dorsal face convex to flat, longer to slightly shorter than the declivitous face. Propodeal angle distinct. Mesosomal spines absent (but propodeal tooth present, spine-like or tooth-like, or rarely reduced to a slight raised angle). Erect pronotal hairs 0-6 (sometimes with a few additional hairs of varying lengths); when present elongate, much longer than the maximum scape width. Dorsal pro-mesonotal junction with the pronotum and mesonotum even (occasionally with either the pronotum or mesonotum slightly raised). Metanotal groove forming a distinct angle between the mesonotum and propodeum, or a distinct, deep trough or notch depressed below the level ofthe adjacent mesosomal notum. Metanotal spiracle lateral and ventral ofthe dorsal surface when viewed in lateral profile, or dorsal and lying on the dorsal surface when viewed in lateral profile. Propodeal spiracle lateral and ventral ofthe propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). PETIOLE. Scale present or reduced; rounded and forming an even arch dorsally, or ridged and with a distinct angle dorsally; varying from moderately inclined anteriorly (but with the anterior and posterior faces approximately the same length) to strongly inclined anteriorly (and with the anterior face much shorter than the posterior face). Venter with a slig ht or weakly developed lobe. GASTER. First tergite vertical and not concealing the petiole in dorsal view and with a groove or indentation for the reception of either the basal portion or the entire height of the petiole. Anterior tergosternal suture ofthe first segment extending laterally from the helcium in a distinct dorsal arch which varies from approximately the same height as, to noticeably dorsal of, the dorsal helcial surface. Fifth tergite ventral, gaster with 4 apparent tergites (sometimes narrowed longitudinally). Gastral compression lateral (greatly developed). Fourth sternite keel-shaped posteriorly. GENERAL CHARACTERS. Worker caste monomorphic. Chromosome number 9 or 13 (n=9, D. ?pulchellus and ?thoracicus, Crozier 1970a; n=13, D. bicolor, Crozier 1970a).lntegumentthin and flexible, weakly sculptured. PROVENTRICULUS. Cupola much broader than bulb; round or lobed; with short pile; smooth, without sculpture; and with short, lateral phragma or without phragma. Bulb partially hidden by cupola in lateral view. Longitudinal muscle No.1 absent. Occlusory tract absent.

Queen
HEAD. Vertex convex. Compound eyes relatively anterior on head. Antennae 12 segmented. Scape short, surpassing the vertex by less than one-half scape length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae about 10-14; long and surpassing the distal edge of the closed mandibles; strongly curved ventrally. Posterior clypeal margin between the anterior and posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. Psammophore present. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal to or longer than the combined lengths of segments 4+5+6. Fifth maxillary palp segment at the apical extreme of segment 4, or subapical and with a finger-like extension distal of the attachment point. Mandible with 5-7 teeth and 0-2 denticles. Apical tooth elongate and much longer than the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin varying from smooth (withoutteeth or denticles) to denticulate distally, smooth proximally. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture complete to weak, nearly absent. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Axilla parallel and entire. Anterior axillar suture straight. Declivitous and dorsal faces of propodeum convex. Propodeal angle indistinct. Propodeal suture absent. Mesosomal spines and tooth absent (but propodeal tooth sometimes present). Erect mesoscutal hairs 0-75; when present short, less than twice the maximum scape diameter. Propodeal spiracle lateral and ventral of the propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). WINGS. Radial cell open. Fore wing with 1- 2 cubital and 0-1 discoidal cells. Hind wing with 1-2 cells. PETIOLE. Scale present; ridged and with a distinct angle dorsally, or spined and with a single tooth or projection dorsally; moderately inclined anteriorly but with the anterior and posterior faces approximately the same length. Venter with a well developed to slight or weakly developed lobe. GASTER. First segment projecting anteriorly and concealing the petiole in dorsal view and with a groove or indentation for the reception of the entire height of the petiole. Fifth tergite vertical and with the distal terminus of the gaster not well defined. Gastral compression absent (gaster circular in cross section). Fourth sternite flat across entire posterior border.

Male
HEAD. Inner margin of eye entire, flat. Scape length at most only slightly longer than the length of funicular segments 1 +2+3. First funicular segment cylindrical or cone-shaped. Second funicular segment cylindrical and with a lateral bend. Funicular segments 2 and 3 at most twice as long as broad. Third and fourth funicular segments straight. Anteromedial clypeal margin entire, without a central notch or concavity of any type. Anterior clypeal setae about 6; about the same length as the closed mandibles; moderately curved ventrally. Posterior clypeal margin between the anterior and posterior surfaces ofthe antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment longer than the combined lengths of segments 4+5. Fifth maxillary palp at the apical extreme of segment 4 (probably also subapical and with a finger-like extension distal of the attachment point, but this could not be confirmed with available material). Mandible with 2-3 teeth and 2 denticles. Apical tooth elongate and much longer than the subapical tooth. Basal angle distinct, with a well developed tooth or angle separating the masticatory and basal margins. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture present, complete. Anteromedial mesosternum even with the lateral regions. Axilla parallel and entire. Anterior axillar suture straight. Declivitous face of propodeum convex to concave; dorsal face convex, subequal in length to the declivitous face. Propodeal angle distinct. WINGS. Radial cell open. Fore wing with no cubital or discoidal cells. Pterostigmal appendage absent. Hind wing with 2 cells. PETIOLE. Scale present; a blunt angle dorsally; vertical and not inclined anteriorly. Venter with a slight or weakly developed lobe. Attachment to gaster broad. GASTER. First segment elongated posteriorly or vertical and not concealing the petiole in dorsal view, smooth and without a groove or indentation or with a groove or indentation for the reception of the basal portion of the petiole. GENITALIA. Pygostyles present, reduced. Posterior margin of subgenital plate convex. Paramere entire. Digitus linear, with or without a down-turned tip (tip sometimes slightly swollen). Cuspis absent. Ventral lobe of volsella present as concave lobe. Aedeagus with ventral teeth.

Larva
Shape dolichoderoid. Protuberances present as a single boss on posterior of body. Body hairs moderately abundant; simple; short. 10 spiracular pairs. Antennae short.