Lasioglossum (Dialictus) kunzei ( Cockerell, 1898 )

Gardner, Joel & Gibbs, Jason, 2020, The ‘ red-tailed’ Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic, European Journal of Taxonomy 725, pp. 1-242 : 111-118

Lasioglossum (Dialictus) kunzei ( Cockerell, 1898)

Figs 49–50 , 51 (left), 95A, 109A

Halictus Kunzei Cockerell, 1898a: 238 (holotype, ♀, depository unknown).

Halictus (Chloralictus) kunzei – Sandhouse 1924: 4 (key).

Lasioglossum (Chloralictus) kunzei – Michener 1951: 1114 (catalog).

Dialictus kunzei – Hurd 1979: 1967 (catalog). — Moure & Hurd 1987: 109 (catalog).

Diagnosis

Females of Lasioglossum kunzei are easily recognized by the head and mesosoma shiny and very finely, sparsely punctate (i=1–6 pd), metapostnotum smooth and shiny, pronotal ridge strongly carinate, and head often large with mandibles elongate and gena with a ventral tubercle. They resemble many socially parasitic L. ( Dialictus ) in these characters, but the well-developed scopa on the hind legs readily identifies L. kunzei as a pollen-collecting species. They are extremely similar to Lasioglossum semibrunneum (Cockerell, 1895) and may be indistinguishable in some cases. Lasioglossum kunzei has a red, nonmetallic metasoma (black with metallic green reflections in L. semibrunneum ), and the postgena tends to be duller and more extensively lineate (shiny with no microsculpture in L. semibrunneum ).

Males of L. kunzei can be recognized by the same characters as for females, except the characters of the head. The head of male L. kunzei is unremarkable except that the compound eyes are only weakly convergent below.They are most similar to L. semibrunneum and may be indistinguishable in some cases. Males of L. kunzei have the discs of the metasomal terga black to brown without metallic reflections, and the rest of the metasoma orange (all brown to black with metallic green reflections in L. semibrunneum ).

Etymology

Cockerell (1898a) dedicated this species to R.E. Kunzé, who collected the type specimen.

Material examined

MEXICO – Baja California • 1 ♀; Mexicali ; [32.62° N, 115.45° W]; 4 Oct. 1941; ex Sinapis alba ; USNM .

UNITED STATES – Arizona • 11 ♀♀; Pinal Co., 11 mi. SW of Eloy; [32.64° N, 111.69° W]; 3 Apr. 1954; T.R. Haig leg.; UCDC • 3 ♀♀; same location as for preceding; 3 Apr. 1934; T.R. Haig leg.; UCDC • 1 ♀; 10 mi. NW of Tucson; [32.33° N, 111.07° W]; 23 Jun. 1961; M. Wargo leg.; UAIC • 1 ♀; Gillespie Dam , 5 mi. S of Arlington; [33.25° N, 112.76° W]; 21 Feb. 1961; J.C. Bequaert leg.; ex Lycium fremontii ; UAIC • 1 ♀; Komatke ; [33.29° N, 112.18° W]; 5 Apr. 1956; F. Werner and G. Butler leg.; ex Medicago sativa ; BBSL • 1 ♀; Phoenix ; [33.45° N, 112.07° W]; 10 Oct.; Cockerell leg.; ex pink oleander; USNM • 1 ♀; Tucson ; [32.22° N, 110.97° W]; 17 Jun. 1957; G.D. Butler leg.; ex Zea mays ; UAIC • 3 ♀♀; Wellton ; [32.67° N, 114.15° W]; 4 Apr. 1956; F. Werner and G. Butler leg.; ex Medicago sativa ; UAIC • 3 ♀♀; same location as for preceding; 4 Apr. 1956; F. Werner and G. Butler leg.; ex yellow composite; UAIC • 8 ♀♀; USNM . – California • 1 ♀; Fresno Co., 20 mi. W of Fireburgh; [36.85° N, 120.82° W]; 6 Jun. 1972; P. Torchio leg.; BBSL • 10 ♀♀; Imperial Co., 10 mi. NW of Calipatria; [33.25° N, 115.6° W]; 27 May 1956; T.R. Haig leg.; UCDC • 3 ♀♀; Imperial Co., 10 mi. W of Calipatria; [33.12° N, 115.69° W]; 27 May 1956; T.R. Haig leg.; UCDC • 1 ♂; same location as for preceding; 23 May 1956; T. R. Haig leg.; UCDC • 3 ♀♀; Imperial Co., 12 mi. E of Heber; [32.73° N, 115.32° W]; 15 May 1956; T.R. Haig leg.; UCDC • 6 ♀♀; Imperial Co., 5 mi. E of Brawley; [32.98° N, 115.44° W]; 24 May 1956; T.R. Haig leg.; UCDC • 2 ♀♀; same location as for preceding; 24 May 1956; T.R. Haig leg.; UCDC • 1 ♀; Imperial Co., 8 mi. E of Brawley; [32.98° N, 115.39° W]; 24 May 1956; T.R. Haig leg.; UCDC • 1 ♀; same location as for preceding; 26 May 1956; T.R. Haig leg.; UCDC • 1 ♀; Imperial Co., Coachella Canal Road 11.6 km NW of CA Hwy 78, then 1.0 km NE; 33.063° N, 115.25° W; 30 May–3 Jun. 2008; UCDC • 1 ♀; Imperial Co., Grays Well Road 3.0 km W of Buttercup Ranger Station; 32.72303° N, 114.90918° W; 18–22 Sep. 2008; UCDC • 1 ♀; Imperial Co., Niland ; [33.24° N, 115.52° W]; 18 Mar. 1956; T.R. Haig leg.; UCDC • 1 ♀; same location as for preceding; 22 May 1956; T.R. Haig leg.; UCDC • 1 ♀; Imperial Co., Palo Verde ; [33.43° N, 114.73° W]; 1 Apr. 1968; R.O. Schuster leg.; UCDC • 2 ♀♀; same location as for preceding; 11 Oct. 1972; C. Goodpasture leg.; UCDC • 1 ♀; same location as for preceding; 10 Oct. 1971; C. Goodpasture leg.; UCDC • 1 ♀; same location as for preceding; 21 Mar. 1967; R.M. Bohart leg.; UCDC • 1 ♀; Imperial Co., Roadrunner Campground , Gecko Road 9.8 km SE of CA Hwy 78; 32.9079° N, 115.11664° W; 31 May–3 Jun. 2008; UCDC • 1 ♀; same location as for preceding; 31 May–3 Jun. 2008; UCDC • 1 ♀; Imperial Co., Wash Road 11.3 km SE of CA Hwy 78, then 1.0 km SW; 32.92347° N, 114.99039° W; 9–18 Oct. 2014; UCDC • 1 ♀; Inyo Co., Brawley ; [32.98° N, 115.53° W]; ex Gossypium ; BBSL • 1 ♀, 19 ♂♂; Inyo Co., China Ranch , 5 mi. SE of Tecopa; 35.79994° N, 116.19547° W; 8 Nov. 2016; Paul A. Rude leg.; EMEC • 13 ♀♀, 4 ♂♂; Riverside Co., 6.5 mi. S of Ripley; [33.43° N, 114.66° W]; 18 Oct. 1959; J.W. MacSwain leg.; ex Sesuvium ; EMEC • 1 ♂; Riverside Co., E Salton Sea, Hwy 111, 28 km NW of Calipatria; [33.34° N, 115.64° W]; 17 Jul. 2010; R.E. Wrigley leg.; WRME • 1 ♀; Riverside Co., Indio ; [33.72° N, 116.22° W]; 11 Mar. 1957; E.I. Schlinger leg.; UCDC • 1 ♀; San Bernardino Co., 9 air mi. S of Baker, Zzyzx Springs ; [35.14° N, 116.1° W]; 22 Apr. 1977; Powell leg.; ex Cleomella obtusifolia ; EMEC • 1 ♀; San Bernardino Co., Salt Springs, Death Valley ; [36.5° N, 116.9° W]; 24 Mar. 1959; C.L. Hogue leg.; LACM • 1 ♀; San Bernardino Co., Zzyzx Springs , 9 mi. S of Baker; [35.14° N, 116.1° W]; 18–28 Apr. 1984; P. Martin leg.; EMEC • 1 ♀; San Diego Co., Borrego Valley ; [33.21° N, 116.23° W]; 11 Apr. 1969; T.R. Haig leg.; UCDC. – Nevada • 3 ♀♀; Clark Co., 0.5 mi. SW of Glendale; 36.6602° N, 114.5781° W; 464 m a.s.l.; 22 Apr. 2004; E. Ahlstrom leg.; ex Prosopis glandulosa var. torreyana ; BBSL • 1 ♀; same location as for preceding; 22 Apr. 2004; S. Higbee leg.; ex Prosopis glandulosa var. torreyana ; BBSL • 1 ♀; Clark Co., 1 mi. N of Warm Springs Rd., 8.5 mi. N of Glendale on HWY 168; 36.7182° N, 114.6913° W; 2 May 1997; F. Parker and V. Tepedino leg.; ex Prosopis ; BBSL • 1 ♀; Carson Sink , 30 mi. NE of Fallen; [39.8° N, 118.42° W]; 24 Aug. 1969; R.M. Peterman leg.; UCDC • 1 ♀; same location as for preceding; 27 Aug. 1969; R.M. Peterman leg.; UCDC . – Utah • 1 ♀; Uintah Co., Bonanza ; [40.02° N, 109.18° W]; Jul. 1977; G. Bohart leg.; BBSL • 10 ♀♀; Washington Co., Santa Clara ; [37.13° N, 113.65° W]; 15 Apr. 1962; G.F. Knowlton leg.; SEMC • 30 ♀♀; Washington Co., St. George ; [37.1° N, 113.57° W]; 14 Apr. 1962; G.F. Knowlton leg.; ex Tamarix ; SEMC • 14 ♀♀; Washington Co., Washington ; [37.13° N, 113.51° W]; 15 Apr. 1962; G.F. Knowlton leg.; ex Tamarix sp.; SEMC • 1 ♀; Myton ; [40.19° N, 110.06° W]; 19 Sep. 1958; Geo. E. Bohart and Wm. P. Nye leg.; BBSL • 1 ♀; Myton , Nomia melanderi Cockerell, 1906 nesting site; [40.19° N, 110.06° W]; 18 May 1962; G.E. Bohart leg.; BBSL • 1 ♀; Saltair ; [40.75° N, 112.19° W]; 21 May 1926; M.C. Van Duzee leg.; CAS • 1 ♂; Santa Clara ; [37.13° N, 113.65° W]; 25 Sep. 1957; G.F. Knowlton leg.; UMSP • 1 ♂; St. George ; [37.1° N, 113.57° W]; 9 Sep. 1954; G.F. Knowlton leg.; SEMC .

Redescription

Female

COLOURATION. Head and mesosoma blue-green; clypeus apical colour reddish brown to orange; labrum reddish brown to orange; mandible orange with black basal spot and red tip; flagellum reddish brown dorsally, orange ventrally; pronotal lobe reddish brown to orange; metasoma orange to reddish brown with basal half of T1 often reddish brown and discs of T4–5 often black, sometimes weakly metallic green, and dark spiracular spots on T2–4; legs mostly dark reddish brown to mostly orange; tegula pale amber to brown; wing membrane hyaline, veins with subcosta dark brown, otherwise light brown.

PUBESCENCE. Body hair colour white. Tomentum dense on pronotal collar and lobe, space between pronotal lobe and tegula, axilla, scutum anterolateral margin, metanotum, preëpisternum, metepisternum, T2–3 basolaterally, and T4 throughout; sparse on paraocular area and gena. Scutum hair thin. Wing hairs dark, short and dense. Acarinarial fan absent or sparse and incomplete with narrow gap. T2 fringes dense, T3 fringes dense.

SURFACE SCULPTURE. Clypeus punctures sparse (i= 1–4 pd), sculpture shiny; supraclypeal area punctures dense marginally (i ≤ 1 pd), sparse medially (i =1–3 pd), sculpture shiny; paraocular area punctures dense dorsally (i <1 pd), becoming moderately sparse ventrally (i= 1–2 pd), sculpture shiny; frons punctures dense (i <1 pd), sculpture shiny; vertex punctures moderately dense (i=1–2 pd), sculpture shiny; gena punctures moderately dense (i=1–2 pd), often obscure, sculpture ruguloso-lineate; postgena sculpture ruguloso-lineate to tessellate; tegula punctures absent; scutum punctures sparse (i=1–6 pd), sculpture shiny;scutellum punctures dense in narrow marginal band and median line(i<1pd),otherwise impunctate, sculpture shiny; metanotum sculpture minutely, densely punctate (i ≤ 1 pd); metapostnotum rugae absent or very short, not reaching halfway to margin, sculpture tessellate; preëpisternum sculpture shiny with crowded punctures (i=0 pd); hypoepimeron punctures moderately dense to sparse (i=1–2 pd), sculpture shiny; mesepisternum punctures moderately dense to sparse (i = 1–2 pd), sculpture shiny; metepisternum sculpture ruguloso-lineate dorsally, imbricate ventrally; propodeum lateral face sculpture imbricate on anterior margin, otherwise tessellate; propodeum posterior face sculpture tessellate; T1 anterior face sculpture shiny; T1 dorsal surface punctures minute, sparse (i=1–3 pd), becoming impunctate medially and apically, sculpture shiny; T2 disc punctures dense and distinct (i ≤ 1 pd) to minute and sparse (i =1–4 pd), disc sculpture shiny, rim punctures minute and sparse (i =1–3 pd) or absent, rim sculpture shiny.

STRUCTURE. Face length/width ratio 0.78 (± 0.04 SD). Clypeus projecting weakly or strongly below suborbital tangent; clypeal area length/width ratio 0.32 (± 0.04 SD); apicolateral denticles normal; supraclypeal area length/width ratio 0.65 (± 0.07 SD). Gena often with ventral tubercle. Forewing with 3 submarginal cells; pronotal angle acute, forming strong dorsoventral ridge; tegula shape normal. Intertegular distance 0.93 (± 0.06 SD) mm. Scutum length/width ratio 0.77 (± 0.04 SD); scutum/ scutellum length ratio 2.7 (± 0.18 SD); scutellum/metanotum length ratio 1.61 (± 0.14 SD); metanotum/ metapostnotum length ratio 0.72 (± 0.11 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. T2 depressed apical rim length 50% or less of segment. (n=10)

Male

COLOURATION. Head and mesosoma blue to olive green; clypeus apical colour black to reddish brown; labrum reddish brown; mandible yellow with black basal spot and red tip; flagellum reddish brown dorsally, yellow-orange ventrally; pronotal lobe reddish brown; metasoma black to orange, sometimes weakly metallic green, with dark spiracular spots on T2–4; legs reddish brown with femur-tibia joints, base and apex of tibiae, and tarsi orange; tegula orange; wing membrane hyaline, veins with subcosta dark brown, otherwise pale amber to brown.

PUBESCENCE. Body hair colour white. Tomentum dense on face below ocelli, gena anteriorly, pronotal angle, preëpisternum, and metepisternum; sparse on gena posteriorly, pronotal lobe, mesepisternum, T1 laterally, T2–4 basolaterally, and T5 throughout. Scutum hair thin to densely plumose. Sterna hair short (0.5–1.25 OD), moderately plumose, sparse and erect. Wing hairs dark or light, short and dense.

SURFACE SCULPTURE. Clypeus punctures irregularly sparse (i ≤ 2 pd), sculpture shiny; supraclypeal area punctures dense (i <1 pd), sculpture shiny; paraocular area punctures dense (i <1 pd), sculpture shiny; frons punctures moderately dense (i=1–2 pd), sculpture shiny; vertex punctures moderately sparse (i =1–2 pd), sculpture shiny; gena punctures sparse (i =1–3 pd), sculpture shiny; postgena sculpture shiny, becoming weakly tessellate to weakly lineate laterad of hypostomal carina; tegula punctures absent; scutum punctures sparse (i=1–6 pd), sculpture shiny; scutellum punctures dense marginally and on median line (i ≤ 1 pd), sparse submedially (i=1–6 pd), sculpture shiny; metanotum sculpture shiny and sparsely punctate (i=1–3 pd); metapostnotum rugae weak, anastomosing, not reaching margin, sculpture shiny to imbricate; preëpisternum sculpture areolate-rugulose; hypoepimeron punctures moderately dense (i= 1–2 pd), sculpture shiny; mesepisternum punctures sparse (i=1–3 pd), sculpture shiny; metepisternum sculpture ruguloso-lineate dorsally, smooth and shiny ventrally; propodeum lateral face punctures sparse (i =1–3 pd), sculpture shiny to weakly rugulose; propodeum posterior face sculpture shiny and sparsely punctate (i=1–3 pd), becoming ruguloso-punctate laterally; T1 anterior face sculpture shiny; T1 dorsal surface punctures minute, sparse (i= 2–4 pd), very sparse or absent in large apicolateral oval patches and on rim, sculpture shiny; T2 disc punctures minute, sparse (i=2–4 pd), disc sculpture shiny, rim punctures minute, very sparse (i =2–6 pd), absent laterally, rim sculpture shiny.

STRUCTURE. Face length/width ratio 0.87 (± 0.01 SD). F1:pedicel length ratio 1.27 (± 0.05 SD); F2:F1 length ratio 1.31 (± 0.1 SD); F2 length/width ratio 1.23 (± 0.09 SD); F9 length/width ratio 1.27 (± 0.11 SD). Forewing with 3 submarginal cells; pronotal angle acute, forming strong dorsoventral ridge; tegula shape normal. Intertegular distance 0.8 (± 0.03 SD) mm. Scutum length/width ratio 0.91 (± 0.04 SD); scutum/scutellum length ratio 2.53 (± 0.19 SD); scutellum/metanotum length ratio 1.92 (± 0.39 SD); metanotum/metapostnotum length ratio 0.74 (± 0.16 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. (n= 3)

GENITALIA. Not examined.

Range

Baja California north to Nevada and east to Utah ( Fig. 51A ).

Floral records

AIZOACEAE Martinov : Sesuvium L. S. portulacastrum (L.) L. (MH87) • S. verrucosum Raf. (MH87) • AMARANTHACEAE Juss. Salsola L. S. kali L. (MH87) • Suaeda Forssk. ex J.F. Gmel. (MH87) • APOCYNACEAE Juss. Nerium L. N. oleander L. • ASTERACEAE Giseke : Baccharis : B. salicina Torr.& A.Gray (MH87) • Dieteria : D. asteroides Torr. D. a. var. asteroides Torr. (MH87) • Pectis : P. papposa Harv. & A.Gray (MH87) • BORAGINACEAE Juss. Heliotropium L. H. curassavicum L. (MH87) • BRASSICACEAE Burnett : Lepidium L. L. virginicum L.(MH87) • Sinapis L. S. alba L. • CLEOMACEAE Bercht. & J. Presl : Cleomella DC. C. obtusifolia Torr. & Frém. • CONVOLVULACEAE Juss. Cressa L. C. truxillensis Kunth (MH87) • FABACEAE Juss. Medicago : M. sativa L. • Prosopis : P. glandulosa Torr. P. g. var. torreyana (L.D. Benson) M.C. Johnst. • MALVACEAE Juss. Gossypium L. • Malvella Jaub. & Spach : M. leprosa (Ortega) Krapov. (MH87) • POACEAE Barnhart : Zea L. Z. mays L. • POLYGONACEAE Juss. Rumex L. (MH87) • SALICACEAE Mirb. Salix L. S. exigua Nutt. S. e. var. hindsiana (Benth.) Dorn (MH87) • SOLANACEAE Adans. Lycium L. L. brevipes Benth. (MH87) • L. fremontii A.Gray • TAMARICACEAE Link : Tamarix L.

DNA barcodes

One sequence available (BOLD process ID: DLIII121-18; BIN: BOLD:AAD0757). This sequence is unique, but poorly distinguished from L. semibrunneum sequences (minimum p-distance 1.11%, compared to maximum p-distance of 2.2% within L. semibrunneum ). Lasioglossum kunzei differs from

all other western red-tailed L. ( Dialictus ) by 1 fixed substitution: 369(C). It differs from L. semibrunneum by an additional 4 fixed substitutions: 219(C), 222(A), 633(C), and 645(T) (Supplementary file 4).

Remarks

The location of the type specimen is unknown ( Moure & Hurd 1987), and was not found despite extensive searching by the authors. Cockerell (1898a) described L. kunzei from a single specimen given to him by C.F. Baker. The type was collected in Phoenix, Arizona on 27 May 1897. A series of specimens in USNM, with labels reading only “Ariz / 2340 // Collection CF Baker” (one specimen with 2572 instead of 2340) might constitute material from which the type was taken. However, none of these are likely to be the type itself, as Cockerell explicitly stated that he only had one specimen. Despite this difficulty, the numerous unique characters possessed by L. kunzei and referenced in the original description allow the name to be quite unambiguously associated.

Lasioglossum kunzei had been considered a likely junior synonym of L. semibrunneum . However, in light of the fairly distinct distributions of the two species west and east of the Rocky Mountains, respectively ( Fig. 51 A–B), it seems advisable to keep them separated. This may be a case of vicariant speciation in action.

The male is described here for the first time.

Figures

Fig. 49. Lasioglossum (D.) kunzei (Cockerell, 1898), ♀. A. Lateral habitus. B. Face. C. Dorsal habitus. D. Propodeum and metasoma. Scale bars: 1 mm.

Fig. 50. Lasioglossum (D.) kunzei (Cockerell, 1898), ♂. A. Dorsal habitus. B. Lateral habitus. C. Face. D. Propodeum. E. Metasoma. Scale bars: 1 mm.

Fig. 51. Georeferenced collection records of Lasioglossum (D.) kunzei (Cockerell, 1898) (vermilion squares), L. (D.) semibrunneum (Cockerell, 1895) (blue-green squares) and intermediate specimens of uncertain identity (yellow squares) as well as predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence. Maxent analysis was run separately for L. (D.) kunzei (left) and L. (D.) semibrunneum (right), but all georeferenced records for both species are shown on both maps to highlight distributional differences. Lasioglossum (D.) kunzei and L. (D.) semibrunneum have largely non-overlapping distributions, but are predicted to intermix in northern Utah, southern Arizona/northern Sonora, and northern Nevada (although no L. (D.) semibrunneum records are known from Nevada).