Lasioglossum (Dialictus) droegei Gibbs, 2009

Gardner, Joel & Gibbs, Jason, 2020, The ‘ red-tailed’ Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic, European Journal of Taxonomy 725, pp. 1-242 : 74-77

Lasioglossum (Dialictus) droegei Gibbs, 2009

Fig. 34–35 , 93B , 111B , 112B

Lasioglossum (Dialictus) droegei Gibbs, 2009b: 387 , figs 14a–b (holotype, ♀, deposited at PCYU, examined).

Diagnosis

Both sexes of Lasioglossum droegei can be recognized by the characters for the Lasioglossum petrellum species complex (below), in addition to the characters given in the keys. They are most similar to L. petrellum ( Cockerell, 1903) . Females of L. petrellum have T2–4 with less extensive tomentum, and usually metasoma with larger brown to black patches laterally. Males of L. petrellum have the T1–3 apical areas slightly shinier and distinctly punctate. In addition, the distributions of these two species are not known to overlap: L. droegei is only known from the Chihuahuan Desert, while L. petrellum is known from the Sonoran Desert and west coast of California and Baja California.

Material examined

Holotype

UNITED STATES – Texas • ♀; Brewster Co.; 29.1466° N, 103.1876° W; 1 May [2002]; H.W. Ikerd leg.; PCYU.

Other material

MEXICO – Nuevo Leon • 1 ♀; 3 km SW of Galeana; [24.81° N, 100.1° W]; 1550 m a.s.l.; 19 Mar. 1991; R. Brooks and R. Leschen leg.; SEMC .

UNITED STATES – New Mexico • 1 ♂; Eddy Co.; 32.178° N, 104.4877° W; 8 Jun. 2010; A. Druk leg.; BBSL . – Texas • 1 ♀; Brewster Co., Big Bend Natl. Park , Oak Canyon ; [29.28° N, 103.33° W]; 1400– 1520 m a.s.l.; 11 Apr. 1986; T. Griswold leg.; ex Penstemon ; BBSL • 1 ♀; Brewster Co., Big Bend Natl. Park , Oak Spring ; [29.282° N, 103.332° W]; 18 Jun. 1999; S. Droege leg.; BBSL .

See also material in Gibbs (2009b).

Description

Female

See Gibbs (2009b) for a complete description and figures of the female.

Male

COLOURATION. Head and mesosoma blue-green to golden-green; clypeus apical colour black with narrow translucent orange flange; labrum reddish brown to orange; mandible orange with black base and red tip; flagellum black dorsally, orange ventrally; pronotal lobe reddish brown; metasoma black to reddish brown with rims of terga and sterna and downcurved lateral areas of terga narrowly translucent brown to orange; legs metallic green with tibiae and basitarsi black and distitarsi reddish brown; tegula orange; wing membrane hyaline, veins dark brown.

PUBESCENCE. Body hair colour white. Tomentum dense on paraocular area, supraclypeal area between antennae, pronotal angle and lobe, and space between pronotal lobe and tegula; sparse on clypeus, gena anteriorly, and metanotum anteriorly. Scutum hair thin. Sterna hair short (0.5–1 OD), moderately plumose, sparse and erect. Wing hairs dark, long and dense.

SURFACE SCULPTURE. Clypeus punctures moderately dense (i=1–2 pd), sculpture finely reticulate in basal ¾, shiny apically; supraclypeal area punctures sparse (i=1–4 pd), sculpture imbricate; paraocular area punctures dense (i <1 pd), sculpture imbricate; frons punctures crowded (i= 0 pd), indistinct, sculpture reticulate; vertex punctures crowded laterally (i=0 pd), absent medially, sculpture imbricate laterally, rugulose medially; gena punctures moderately dense (i=1–2 pd), sculpture shiny, becoming imbricate and weakly lineate posteriorly and ventrally; postgena sculpture finely reticulate, becoming weakly lineate posteriorly; tegula punctures absent; scutum punctures dense (i <1 pd), sculpture finely reticulate; scutellum punctures dense marginally and on median line (i <1 pd), moderately sparse submedially (i=1–2 pd), sculpture finely reticulate; metanotum sculpture imbricate and densely punctate (i <1 pd); metapostnotum rugae strong, anastomosing, not reaching margin, sculpture finely reticulate; preëpisternum sculpture rugulose; hypoepimeron punctures absent, sculpture finely reticulate; mesepisternum punctures dense (i <1 pd), indistinct, sculpture finely reticulate; metepisternum sculpture lineate dorsally, rugulose ventrally; propodeum lateral face punctures obscure, sculpture finely reticulate; propodeum posterior face sculpture imbricate and densely punctate laterally (i <1 pd), becoming shiny and sparsely punctate medially (i=1–4 pd); T1 anterior face sculpture weakly coriarious; T1 dorsal surface punctures crowded (i=0 pd), becoming dense laterally (i ≤ 1 pd), sculpture weakly coriarious, becoming finely reticulate apically; T2 disc punctures crowded (i =0 pd), becoming dense laterally (i ≤ 1 pd), disc sculpture weakly coriarious, becoming finely reticulate apically, rim punctures dense (i <1 pd), rim sculpture finely reticulate.

STRUCTURE. Face length/width ratio 0.91. F1:pedicel length ratio 1.29; F2:F1 length ratio 1.55; F2 length/ width ratio 1.7; F9 length/width ratio 1.37. Forewing with 3 submarginal cells; pronotal angle obtuse; tegula shape normal. Intertegular distance 1.08 mm. Scutum length/width ratio 0.88; scutum:scutellum

length ratio 2.57; scutellum:metanotum length ratio 1.72; metanotum:metapostnotum length ratio 0.74. Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. (n= 1)

GENITALIA. Not examined.

Range Chihuahuan Desert from New Mexico and Texas to Nuevo Leon ( Fig. 35 ).

Floral records

LAMIACEAE Martinov : Hedeoma Pers. H. apiculata W.S. Stewart (G09) • PLANTAGINACEAE Juss. Penstemon Schmidel.

DNA barcodes

Five sequences available (BOLD process IDs: DLII034-06, DLII035-06, DLII1302-08, DLII1538- 09, LASNA009-08; BIN: BOLD:AAZ1858). Lasioglossum droegei differs from all other western red-tailed L. ( Dialictus ) by 1 fixed substitution: 303(C). It differs from L. griswoldi , L. petrellum , and L. tuolumnense by an additional 2 fixed substitutions: 117(C) and 228(G) (Supplementary file 4).

Remarks

Gibbs (2009b) recorded L. droegei from only a single location in Texas. Additional specimens are now known from New Mexico and Nuevo Leon. The male is described here for the first time.

Figures

Fig. 34. Lasioglossum (D.) droegei Gibbs, 2009, ♂. A. Dorsal habitus. B. Lateral habitus. C. Face. D. Propodeum and metasoma. Scale bars: 1 mm.

Fig. 35. Georeferenced collection records of Lasioglossum (D.) droegei Gibbs, 2009 (black squares) and predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence. The predicted distribution was generated with a regularization multiplier of 0.5 to obtain a more conservative prediction. Due to the very small number of records, this distribution should be interpreted with caution.

Fig. 93. Mesoscutum. A. Lasioglossum (D.) tessellatosum sp. nov., ♀, with strong microsculpture and sparse punctures. B. L. (D.) droegei Gibbs, 2009, ♂, with strong microsculpture and dense punctures. C. L. (D.) cactorum sp. nov., ♀, shiny and sparsely punctate. Scale bars: 0.5 mm.

Fig. 111. T1 anterior surface. A. Lasioglossum (D.) vierecki (Crawford, 1904), ♂, with dense appressed hair. B. L. (D.) droegei Gibbs, 2009, ♂, without appressed hair. Scale bars: 0.5 mm.

Fig. 112. T2. A. Lasioglossum (D.) petrellum (Cockerell, 1903), ♂, with weaker microsculpture and distinct punctures throughout.B. L. (D.) droegei Gibbs, 2009, ♂, with strong microsculpture and obscure punctures towards apical rim. Scale bars: 0.5 mm.