Trachusoides elsieae, Griswold, Terry, 2015

Griswold, Terry, 2015, A review of Trachusoides Michener and Griswold (Hymenoptera: Megachilidae), Zootaxa 3949 (1), pp. 147-150 : 149-150

Trachusoides elsieae sp. nov.

( Figs.1–5 )

Type material. Holotype female, “ LAOS: Vientiene Prov. Ban Van Eue 29.III.1966 ” / “Native Collector BISHOP MUS.” The holotype resides in the Bernice Pauahi Bishop Museum, Honolulu, HI.

Diagnosis. This new species differs from Trachusoides simplex in reduced markings ( Fig. 1 ; no maculations on mesosoma, legs, T1–T4); mandible 5-toothed ( Fig. 4 ); scutoscutellar suture open, forming two narrowly separated foveae ( Fig. 5 ); hind tibial spurs with coarse, well defined teeth ( Fig. 3 ); clypeus densely, but not contiguously, punctate; scopal hairs light throughout. Trachusoides elsieae could easily be confused with Trachusa longicornis (Friese) . Both have the body predominately dark with only T5 and T6 yellow, and both have a 5-toothed mandible. The most notable differences are the presence of a lamellate omaulus, tarsal claws with preapical tooth, vertex long, shiny, sparsely punctate, and hind tibial spurs shorter, minutely dentate in Trachusa longicornis .

Description. Female body length, 12.5 mm; forewing length, 8 mm. Head: Carinae absent. Inner orbits subparallel, upper halves gently concave. Clypeus convex in profile, hexagonal, dorsal margin between subantennal sutures arched, ventral margin with seven denticles between which arise short tufts of bristles. Labrum weakly sclerotized, little longer than broad, apex with long bristles. Mandible rather long, greatly expanded apically to more than twice minimal width, 5-toothed, outer surface dull, minutely roughened except for smoother distal margin, outer and condylar ridges very narrow but strongly elevated, shining, outer ridge extending halfway to base of mandible, condylar ridge shorter, extending only one third of distance to base of mandible. Labial, maxillary palpus not visible. Subantennal suture straight, scarcely longer than diameter of antennal socket, obliquely angled toward midline ventrally, joining epistomal suture above tentorial pit. Interantennal distance slightly more than twice antennocular distance; head well developed behind and above ocelli so that ocelloccipital distance nearly twice interocellar distance; ocellocular distance about 1.5 times interocellar distance; ocelli below upper ocular tangent. Genal area as wide as eye in lateral view, widest below middle of eye. Scape reaching level of anterior ocellus; first flagellar segment approximately 1.5 times as long as broad, second and third broader than long, fourth as long as broad, following segments progressively longer until ninth 1.5 times as long as broad, tenth over twice as long as broad. Mesosoma: Without carinae except for strong carina on pronotal lobe; omaulus rounded; anterior margin of scutum gradually bent downward, without smooth vertical surface; axilla, scutellum with posterior margins convex in dorsal view, without median scutellar emargination, margins not carinate, rounded in profile, strongly overhanging metanotum and base of propodeum; scutoscutellar suture open, forming two narrowly separated foveae. Propodeum without basal pits or postspiracular fovea, profile convex, upper two-fifths declivous but not vertical, curving gradually onto vertical lower three-fifths. Basitarsi each longer than remaining tarsal segments combined, anterior and posterior basitarsi widest near bases and slightly tapering, mid basitarsus parallel sided, as long as tibia; hind basitarsus nearly four times as long as broad. Front, mid tibiae each with single, strong blunt midapical spine largely hidden by short pubescence; mid tibia slightly narrower than hind tibia, with anterior and posterior margins equally, symmetrically convex in lateral view; hind tibia with apex truncate, apical margin only slightly convex medially; tibial spurs nearly straight, outer spur coarsely serrate. Claws simple. Arolia absent. Metasoma: T2, T3 widest; T1 with carina margining basal concavity, horizontal surface one third as long as vertical surface; tergal graduli ending near spiracles, not bent posteriorly; T6 unmodified, profile straight, margin not denticulate. S6 very slightly exceeding T6 medially, not modified. Posterior zones of terga scarcely depressed, without impunctate margins. Punctation: Dense throughout, finer on clypeus, lower paraocular, genal areas than rest of head, thorax; foveolate on frons, scutum; propodeum impunctate on ventral half of posterior face; tibiae not more coarsely punctate than body, surfaces not tuberculate; posterior margins of T3 to T5, all of T6 more finely punctate than clypeus; sterna with basal, apical zones impunctate. Pubescence: Mixture of pallid, dark on lower half of face; dusky on remainder of head, all mesosoma; T1 to T3 dark, T4 mixture dark and yellow, T5 and T6 yellow; scopa entirely yellow. Pubescence of clypeus mostly erect, mostly very short, scattered longer hairs; bristles of clypeal apex yellow, labral apex amber; lower margin of mandible with series of about six widely spaced long, erect bristles. Rest of head with pubescence rather sparse (where not worn off); mesosoma with pubescence dense (where not worn off), slightly longer on sides, venter, propodeum. Metasoma with pubescence of terga short, dense, obliquely directed posteriorly except longer, sparser on T1 dorsally, not particularly denser on posterior zones. Scopa dense, long on S2 to S5. Integument: Black on head (except clypeus dark brown), mesosoma, T1 to T4 (except brownish apically). Flagellar segments four to ten grayish. Fore, mid legs dark brownish. Wings yellowish, darker near costal margin, distal veins amber to yellow. T5, T6 yellow.

Male: Unknown.

Etymology. It is a great pleasure to recognize my third grade teacher, Elsie Williams of Bowman, California, who inspired me with a love of learning, whose adventurous spirit has taken her to several continents, including a teaching assignment in Lesotho in “retirement”, and who, at age 98 still inspires me with her exuberant interest in the world around her.

Comments. The type location is actually Ban Van Heue, 20 km E of Phou-kow-kuei in Vientiane Province ( Evenhuis 2006).

Figures

FIGURES 1 – 5. Trachusoides elsieae sp. nov., female. Fig. 1, lateral habitus; Fig. 2, frontal view; Fig. 3, outer hindtibial spur; Fig. 4, mandible; Fig. 5, dorsum of mesosoma showing scutal-scutellar suture. Scale bar equals 0.5 mm.