Myrmecocystus christineae

Identification
The present species appears to be annectant between the mexicanus group and the pyramicus group. The mesosomal profile of the worker is very similar to that of mexicanus group species, as is the number of mandibular teeth of the female and worker. The displacement of the eyes of the worker toward the occipital margin is about as in the pyramicus group, although this is shared with navajo in the mexicanus group. The great reduction in erect body hairs in both female and worker accords with the pyramicus group.

Worker. Erect hairs absent from malar area, scape tibiae and mesosomal dorsum; upper margin of eye little below occipital corner; basal face of propodeum flat or slightly rounded in profile. Queen: Fifth segment of maxillary palp broadest in middle; OOD 1.8-2.5 X OD; scape, except at apex, with fine, appressed pubescence only; tibial hairs decumbent, sparse; mesoscutum, between parapsides, with sparse, fine punctures and scattered coarse punctures, center nearly impunctate. Male: Scape with appressed pubescence only, except at tip; tibiae with very short decumbent hairs; forewing with fringe hairs along apical margin, hindwing with fringe hairs along apical and posterior margins; forewing without discoidal cell; HL less than 0.8 mm. (Snelling 1982)

Distribution
Known from the Ivanpah and Granite Mountains in California. The species probably occurs in suitable habitats of adjacent ranges in California and Nevada.

This taxon was described from U.S.A.

Nomenclature

 *  christineae. Myrmecocystus (Myrmecocystus) christineae Snelling, R.R. 1982b: 80, figs. 7-12, 14, 16, 20, 22, 24 (w.q.m.) U.S.A.

Worker
Measurements: HL 0.77-1.13 (1.12); HW 0.63-1.03 (1.02); SL 0.97-1.33 (1.33); WL 1.03-1.63 (1.63); PW 0.43-0.72 (0.70) mm.

Head: Longer than broad, CI 75-94 (91), a little shorter than scape, SI 113-130 (119). In frontal view, sides of head nearly parallel in small workers, slightly convex in largest workers and widest at about midpoint of malar area. Occiput, in frontal view, flat, sides convex, not at all angulate. Eye large, EL 1.4-1.7 (1.5) X first flagellomere; OMD 0.75-1.04 (1.00) X EL; upper margin nearly coincident with occipital corner. Mandible with seven or eight teeth.

Thorax: Moderately robust to robust, PW 0.43-0.72 (0.70) X WL. Basal face of propodeum, in profile, flat or slightly rounded, broadly rounded into longer posterior face.

Petiole: Elongate-cuneate in profile, summit narrowly rounded; crest, from behind, weakly notched; from above about twice wider than long.

Vestiture: Clypeus with a few erect hairs; two pair of very short erect hairs on margins of fronta1 10bes and a pair on vertex. Thorax without erect hairs. Crest of petiole without erect hairs. First two gastric terga without erect hairs on disc; remaining terga with scattered suberect disca1 hairs. Scape and outer tibial faces without visible hairs of any declination.

Pubescence fine, sparse and short on head and mesosomal dorsum; longer and a little denser on mesosomal side and on gastric terga; everywhere appressed, but with some suberect pubescence on basal area of first tergum.

Integument: Moderately shiny over most areas, clypeus polished, with scattered fine punctures; malar area somewhat shagreened, with sparse, elongate punctures; frontal lobes closely, sharply and finely punctate; frons and vertex similar but punctures a little finer.

Color: Light brownish yellow; occiput sometimes brownish; appendages paler.

Queen
Measurements: HL 1.67-1.73; HW 1.67-1.77; SL 1.57-1.67; EL 0.53-0.57; WL 3.5-3.7; PW 2.0-2.2 mm.

Head: As broad as, or a little broader than long, CI 100-104; longer than, or as long as, scape, SI 92-100. In frontal view, broadest below eyes, sides weakly convex. Occiput, in frontal view, flat, corners broadly rounded. Eye large, EL 1.3-1.5 X first flagellomere; OMD 1.0-1.6 X EL; IOD 2.2-2.9 X OD; OOD 1.8- 2.5 X OD. Mandible variable, usually with five conspicuous, widely spaced teeth (in addition to apical tooth) and with two to four smaller denticles between these. Fifth segment of maxillary palp broad over much of its length, narrowed at base and apex.

Thorax: Robust, PW 0.54-0.63 X WL. In profile, posterior two-thirds of mesoscutum flattened. Scutellum slightly convex, strongly sloping and forming continuous plane with metanotum and base of propodeum.

Petiole: Compressed in profile, crest narrowly rounded; distinctly notched in frontal view; from above, about three times wider than long.

Vestiture: Head with sparse, short, suberect hairs across occiput and with scattered longer hairs (about 0.5 X MOD); frontal lobes with sparse short, suberect to erect hairs; clypeus with numerous short and long suberect to erect hairs on disc; malar area with 3-6 short, decumbent to suberect hairs. Mesoscutum with scattered short and long, suberect to erect hairs; scutellum with 4-6 long, erect hairs and a few short, erect hairs; side of thorax with widely scattered, short, erect hairs; propodeum without erect hairs over base, disc and sides; terga with scattered, short, suberect to erect hairs on discs which are progressively longer on succeeding segments. Inner face of profemur without erect hairs, though 15+ present along lower margin; meso- and metatibia with numerous fine, decumbent hairs.

Forewing with fringe hairs along apical margin; hindwing with fringe hairs along apical and posterior margins.

Pubescence appressed, general, abundant only on malar area, sides of thorax, propodeum, scape and first four terga.

Integument: Clypeus and supraclypeal area smooth or lightly shagreened between sparse, coarse punctures; frontal lobes moderately shiny between close micropunctures and sparse coarse punctures; occiput dull and shagreened between close micropunctures and sparse coarse punctures; malar area dull and shagreened between close, coarse, elongate punctures.

Pronotum moderately shiny, sides and dorsal margin closely micropunctate, neck with punctures very obscure. Parapsis shiny, with close micropunctures and sparse coarse punctures; mesoscutal disc shiny, with sparse micropunctures, nearly impunctate in middle. Scutellum shiny, with scattered micropunctures and a few coarse punctures (from which the long hairs arise). Anepisternum and katepisternum moderately shiny between close micropunctures and sparse coarse, piliferous punctures. Propodeum dull, densely shagreened and closely micropunctate.

First three terga shiny between close micropunctures and scattered coarse punctures, punctures a little more separated and less distinct on second segment.

Color: Yellow, frontal area of head light brown; appendages paler yellow. Wings clear, veins and stigma light to medium brown.

Male
Measurements: HL 0.62-0.70 (0.66); HW 0.53-0.60 (0.57); SL 0.66-0.73 (0.66); EL 0.28-0.30 (0.30); OMD 0.10-0.15 (0.13); WL 1.23-1.40 (1.30); PW 0.70-0.80 (0.77) mm.

Head: Margins slightly convergent toward mandibular insertions; distinctly longer than broad, CI 79-88 (85); a little shorter than, to a little longer than, scape, SI 95-114 (100); OMD 0.33-0.50 (0.44) X EL; anterior ocellus little smaller than lateral ocelli; IOD 2.50-3.50 (3.00) X OD; OOD 1.00 X OD. Mandible without preapical teeth, preapical notch weak or absent. Clypeus usually with transverse preapical depression.

Thorax: Stout, PW 0.52-0.59 (0.59) X WL. Propodeum, in profile, without defined basal face.

Petiole: Sharply cuneate in profile; in frontal view, crest weakly notched; in dorsal view about twice wider than long.

Vestiture: Erect hairs short and sparse on clypeus, absent from frontal lobes; a single pair, short and suberect, in ocellar area; absent from meso scutum; four to six short, suberect hairs on scutellum; first three terga without erect hairs, but with sparse, decumbent hairs; remaining terga and the sterna with moderately long, suberect to erect sparse hairs. Hairs of tibiae short, fine and decumbent to appressed. Scape with appressed pubescence only. Wings as in female.

Integument: Moderately shiny on most areas, shiny between notaulices, with sparse piligerous micropunctures: scattered coarse punctures on mesokatepisternum.

Color: Uniformly brownish; appendages pale yellowish. Wings clear, veins and stigma light brown.

Terminalia: Figures 20, 22, 24.

Type Material
Holotype worker, Morningstar Mine Rd., elev. 4200'-4260', 9.5 mi NNE Cima, San Bernardino Co., CALIF., 14 Apr. 1977 (c. D. George and R. R. Snelling; RRS No. 77-9); allotype male, same data but RRS No. 77-10; holotype and allotype in. Paratypes: 16 females, 724 workers, 68 males, same data, RRS No. 77-9, 10, 16. Paratypes in, GCW, LACM, ,.

Etymology
This species is dedicated to Christine D. George who materially assisted in collecting and studying this new species and who is currently investigating Myrmecocystus ecology in the Mojave Desert.