Microsphecodes septentrionalis Graham & Packer, 2024

Graham, Liam & Packer, Laurence, 2024, Three New Species of Microsphecodes s. str. (Hymenoptera: Halictidae) with an updated key to species of the subgenus, Zootaxa 5404 (1), pp. 189-205 : 197-198

Microsphecodes septentrionalis Graham & Packer

Figs. 12 , 13 , 19–23 , 30 & 32 .

Diagnosis: The marginal carina around the dorsal surface of the metapostnotum is absent posteromedially, a unique feature to this species within the subgenus. The combination of the head, mesosoma, and T1 of the metasoma ( Figs. 19–22 ) being orange-brown is also unique: other species have either at least some of these parts marked with black or dark brown or the pale colouration is more extensive on the metasoma.

Description: Holotype female:

Dimensions: Total body length 4.14 mm; forewing length 3.48 mm. Head broader than long, width 1.3 mm, length 1.05 mm. Intertegular distance approximately 0.76 mm (somewhat distorted by pin).

Colouration: Pale brown-orange except as follows: Mandibles darker brown-orange, apical 1/6 red; labrum and clypeus yellow-orange; torulus and extreme base of scape orange; pedicel and flagellum brown; pronotum yellow; tegula dark yellow; wing veins yellow, wing membrane translucent. All legs entirely yellow. T1 & T2 yellow, with some light brown patches apicolaterally, and a thin dark brown line along the apical margin, with some darker markings throughout the disc [these darker markings result from internal structures visible through the translucent terga]; T2–T3 light brown; T4–T5 dark brown; pygidial plate dark red-brown; S1–S2 yellow; S3 yellow on disc margins dark brown, S4 yellow basally, brown apically; S5 dark brown.

Pubescence: Pale yellow (almost white) relatively sparse fine simple sub-erect to erect except when stated otherwise; clypeus and lower paraocular area hairs dense with short branches, mostly longer than on rest of face with some medium length hairs intermixed; less dense on vertexal area face, generally shorter than longest hairs of clypeus, some long hairs intermixed; anterior surface of flagellum hairs dense and short with underlying placodea obscure but present. Pronotal collar covered in short, dense white hair; side of mesosoma with dense somewhat plumose short white subappressed hairs, sparse erect long white hairs intermixed; hypoepimeral with short sparse erect hairs. Metatibia hairs pale, mostly simple suberect longest apicoventrally shorter than apical width of tibia. T1 hairs on lateral surface only, medium to long, sparse and erect; T2 with short sparse suberect hairs basally and laterally on disc some long hairs intermixed laterally, anteriorly glabrous; T3–T4 hairs sparse and short on disc, medium to long laterally; T5 hairs longer and more dense than on other terga with some longer hairs intermixed. S1 hairs sparse medium length; S2–S5 with scattered long suberect hairs not restricted to apical halves.

Surface Sculpture: Integument shiny lacking microsculpture unless stated otherwise. Entire head except hypostomal area, densely punctate i<0.5–1d; small impunctate shining area anterior to median ocellus, roughly 1 MOD. Hypostomal area shining, obscurely punctate among sparse but coarse microsculpture. Pronotum impunctate and imbricate. Mesoscutum densely irregularly punctate, i=0.5–3xd, denser laterally and posteriorly where punctures smaller; mesoscutellum impunctate on disc except midline densely punctate, anterior and posterior margins densely punctate, i=0.5–1d, punctures small; metanotum densely punctate, i=0.5d. Metapostnotum dorsal surface margined by carina that is effaced medially; areolate, median pair of areolae on either side of median carina take up most of the dorsal surface, unequal in size, margined by smaller elongate areolae; hypoepimeral area weakly punctate, i=d; propodeum coarsely areolate, areolae on posterior surface large. Tegula impunctate weakly imbricate anteriorly. T1 punctures sparse and shallow i=3–7d; T2–T5 punctures scattered minute hair-bearing. S1–S6 punctures small hair-bearing only, microsculpture weak to absent.

Structure: Mandible slightly shorter than compound eye (0.6 mm: 0.74 mm). Clypeus 3.6 times broader than long (0.82 mm: 0.23 mm). Supraclypeal area convex, somewhat protuberant in profile. Frontal line carinate from lower tangent of antennal socket to <1 MOD below median ocellus (MOD = 0.12 mm). Inner margin of compound eyes somewhat convergent below (UOD:LOD 0.84 mm: 0.76 mm); ASD 0.26 mm, IAD 0.2 mm; supraclypeal area apical width 0.16mm, length 0.26 mm; IOD:OOD 0.18 mm: 0.28 mm; vertex strongly convex in frontal view, upper tangent of compound eyes 0.5 MOD below lower tangent of median ocellus; genal area narrower than compound eye in profile (0.3 mm: 0.36 mm). F1 equal in length to F2 (0.1mm: 0.1mm). Mesoscutum shorter than ITW, 0.68mm: 0.76mm. Stigma large, 0.52 mm long 0.22 mm wide, stigmal perpendicular goes through anterior extremity of vein 2r-m; margin in marginal cell weakly convex, marginal cell 0.94 mm long, 0.27mm wide, free portion more than 3X the length of that subtended by submarginal cells (0.26 mm: 0.8 mm); 1m-cu meets second submarginal cell beyond middle; hind wing with five distal hamuli. Pygidial plate apically rounded.

Material Studied. Holotype female: GUATEMALA, Moca , Guatalon, [14.5 -91.33] 1,000m. Mar. Apr. [19]31 |, J. Bequaert ( MCZ).

Etymology: The species name indicates the northern locality for this species.

Comments: This species extends the geographic range of the genus approximately 500km further north. However, there is a specimen of the genus from Morelos, Mexico at UNAM which we have not seen. See below for a discussion on stigma size in the Sphecodina .

The incomplete metapostnotal carina is of interest as this is complete in other species of the nominate subgenus, but absent in M. ( Baeosphecodes ).

Figures

FIGURE 13. Map showing locations of captures of Microsphecodes (Microsphecodes) species. Note that the black symbol indicates an area where three species have been found.

FIGURES 10–12. Head, frontal view of the three new species of Microsphecodes being described herein. Fig. 10—Holotype of M. peckorum Graham and Packer, sp. n.; Fig. 11—Holotype of M. fernandoi Graham and Packer, sp. n. Fig. 12—Holotype of M. septentrionalis Graham and Packer, sp. n.

FIGURES 19–23. Holotype of M. septentrionalis Graham and Packer, sp. n. Fig. 19.—lateral habitus; Fig. 20 –posterior half of mesosoma to show metapostnotal sculpture; Fig. 21.—dorsal view of mesosoma; Fig. 22—dorsal view of metasoma; Fig. 23—forewing.

FIGURES 29–32. Metasomal dorsum (Figs. 29&30) and metapostnotum (Figs. 31&32) of:Figs.29&39—M.fernandoi Graham and Packer, n. sp. and Figs. 30&32—M. septentrionalis Graham and Packer, n. sp.