Lasioglossum (Dialictus) pallidellum ( Ellis, 1914 )

Gardner, Joel & Gibbs, Jason, 2020, The ‘ red-tailed’ Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic, European Journal of Taxonomy 725, pp. 1-242 : 155-161

Lasioglossum (Dialictus) pallidellum ( Ellis, 1914)

Figs 67–69 , 90K , 100A , 104A

Halictus pallidellus Ellis, 1914a: 151 (holotype, ♀, deposited in UCMC, examined).

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

Lasioglossum (Chloralictus) pallidellum – Michener 1951: 1116 (catalog).

Dialictus pallidellus – Hurd 1979: 1969 (catalog). — Moure & Hurd 1987: 119 (catalog).

Lasioglossum (Dialictus) pallidellum – Gibbs 2010: 234 , fig. 169a–c (key, redescription). — Scott et al. 2011: 30 (checklist).

Diagnosis

Females of Lasioglossum pallidellum can be recognized by most of the body covered in very dense white tomentum, head and mesosoma shiny and sparsely punctate (i =1–3 pd), metapostnotum shiny with weak rugae not reaching the rounded posterior margin, face short (length/width ratio ~0.78), and T2–4 with dark spiracular spots. They are most similar to L. julipile sp. nov. Females of L. julipile sp. nov. have the metapostnotum with strong rugae reaching the posterior margin and T2 without dark spiracular spots.

Males of L. pallidellum can be recognized by the same characters as for females, although the metapostnotal rugae are sometimes stronger and nearly reaching the posterior margin, and the dark spiracular spots are only visible in red-tailed forms. In addition, they have the flagellomeres relatively short (F2 about 1.75 times as long as F1 and 1.25 times as long as broad), gonocoxite very broad, and gonostylus large and boot-shaped. They are most similar to L. julipile sp. nov. Males of L. julipile sp. nov. have the mesosoma and metasoma with less extensive tomentum (especially noticeable on T2–4 basolaterally), metasoma always completely black, and gonocoxite and gonostylus narrower with no unusual modifications.

Etymology

Ellis (1914a) named this species from the Latin adjective ‘ pallidus ’ (‘pale’, ‘ashen’) and the diminutive suffix ‘- ellus ’.

Material examined

Holotype

UNITED STATES – New Mexico • ♀; Roswell ; [33.39° N, 104.52° W]; 14 Apr.; Cockerell leg.; ex Prunus ; UCMC.

Other material

MEXICO – Coahuila • 1 ♀; 18 km S of Cuatrociénegas; 26.8667° N, 102.1333° W; 920 m a.s.l.; 27 Mar. 1992; D. Yanega leg.; ex Prosopis glandulosa ; SEMC • 4 ♀♀; Churince Spring , 18 km S of Cuatrociénegas; [26.84° N, 102.134° W]; 15 Feb. 2000; R.L. Minckley leg.; ex Acacia greggii ; RLM . – Nuevo Leon • 1 ♀; 2.7 km S of El Refugio de Cedilla; 23.9825° N, 100.294583° W; 1973 m a.s.l.; 18 Sep. 2008; G.R. Ballmer leg.; SEMC .

UNITED STATES – Arizona • 2 ♀♀; Cochise Co., Willcox ; [32.25° N, 109.83° W]; Aug. 2005; L. Packer leg.; PCYU • 1 ♀; Willcox ; [32.25° N, 109.83° W]; 2005; L. Packer leg.; PCYU . – California • 1 ♀; Fresno Co., Mendota ; [36.75° N, 120.38° W]; 23 Apr. 1949; J.W. MacSwain and R.F. Smith leg.; ex Melilotus ; EMEC • 2 ♀♀; Inyo Co., 2 km NW of Swansea; [36.54° N, 117.93° W]; 19 Sep. 1993; T. Griswold leg.; ex Ericameria nauseosa var. nauseosa ; BBSL • 3 ♀♀; same location as for preceding; 19 Sep. 1993; T. Griswold leg.; ex Oxystylis lutea ; BBSL • 2 ♀♀; Inyo Co., 2.9 mi. S of Shoshone; [35.929° N, 116.269° W]; 18 Oct. 1956; A.C. Dickson leg.; ex Aplopappus ; UCRC • 1 ♀; Inyo Co., 3.5 mi. W of Lone Pine; [36.6° N, 118.125° W]; 8 Jul. 1961; H.V. Daly leg.; EMEC • 3 ♀♀; Inyo Co., Death Valley Junction ; 36.3142° N, 116.4567° W; 671 m a.s.l.; 19 Sep. 2013; M.C. Orr leg.; ex Cleomella obtusifolia ; BBSL • 1 ♀; Inyo Co., Eureka Dunes, North inner ; 37.0986° N, 117.6776° W; 20 Apr. 1999; R. Andrus and T. Griswold leg.; ex Astragalus lentiginosus ; BBSL • 1 ♀; Inyo Co., Keeler ; [36.49° N, 117.87° W]; 28 Aug. 1977; E.G. and J.M. Linsley leg.; ex Tamarix aralensis ; EMEC • 1 ♀; Inyo Co., Lone Pine Creek ; [36.6° N, 118.085° W]; 1219 m a.s.l.; 31 Aug. 1969; R.M. Bohart leg.; UCDC • 1 ♀; Inyo Co., Saline Valley, Salt Lake ; [36.7° N, 117.82° W]; 323 m a.s.l.; 23 May 1976; D. Giuliani leg.; LACM • 1 ♀; same location as for preceding; 7 Jun. 1976; D. Giuliani leg.; LACM • 1 ♀; Inyo Co., Saline Valley, Upper Warm Spring ; [36.813° N, 117.766° W]; 579 m a.s.l.; 6 Apr. 1976; D. Giuliani leg.; LACM • 2 ♀♀; Inyo Co., Shoshone ; [35.97° N, 116.27° W]; 22 Sep. 1966; J.C. Hall leg.; ex Oxystylis lutea ; UCRC • 1 ♀; Lassen Co., Amedee ; [40.3° N, 120.2° W]; 4 Jul. 1947; T.F. Leigh leg.; EMEC • 1 ♀; San Bernardino Co., 9 air mi. S of Baker, sand dunes S of Zzyzx Springs; [35.14° N, 116.1° W]; 27 Apr. 1977; Powell leg.; EMEC • 2 ♀♀; same location as for preceding; 27 Apr. 1977; J. Doyen leg.; ex Cleomella obtusifolia ; EMEC • 3 ♀♀; 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 • 2 ♀♀; same location as for preceding; 23 Apr. 1977; Powell leg.; ex Cleomella obtusifolia ; EMEC • 2 ♀♀; same location as for preceding; 20 Apr. 1977; R. Cave leg.; EMEC • 4 ♀♀; same location as for preceding; 20 Apr. 1977; J. Doyen leg.; ex Tamarix ; EMEC • 1 ♀; same location as for preceding; 20–21 Apr. 1977; M. Buegler leg.; EMEC • 1 ♀; San Bernardino Co., Zzyzx Spring ; 35.1333° N, 116.1° W; 22–24 May 1982; J.P. and K.E.S. Donahue leg.; AMNH • 28 ♀♀; same location as for preceding; 22–24 May 1982; J.P. and K.E.S. Donahue leg.; LACM • 1 ♀; San Bernardino Co., Zzyzx Springs ; [35.14° N, 116.1° W]; 22 Apr. 1984; Dan Sandri leg.; EMEC • 4 ♀♀; San Bernardino Co., Zzyzx Springs , 9 mi. S of Baker; [35.14° N, 116.1° W]; 18–28 Apr. 1984; P. Martin leg.; EMEC • 3 ♀♀; same location as for preceding; 21–23 Apr. 1984; EMEC • 1 ♀; Tulare Co., Wood Lake ; [36.41° N, 119.1° W]; 1 May 1947; Norman W. Frazier leg.; EMEC • 1 ♀; 1.3 mi. E of Little Rock; [34.52° N, 117.96° W]; 13 Sep. 1950; Timberlake leg.; ex Gutierrezia microcephala ; UCRC • 1 ♀; 12 mi. SE of Palm Springs; [33.71° N, 116.39° W]; 12 Nov. 1952; Timberlake leg.; ex Eriogonum trichopes ; UCRC • 2 ♀♀; Twentynine Palms ; [34.13° N, 116.06° W]; 9 Aug. 1946; Timberlake leg.; ex Wislizenia refracta ; UCRC • 3 ♀♀; same location as for preceding; 4 Aug. 1933; Timberlake leg.; ex Wislizenia refracta ; UCRC • 1 ♀; same location as for preceding; 1946; A.L. Melander leg.; UCRC • 1 ♀; 5 mi. N of Lancaster; [34.75° N, 118.15° W]; 29 Sep. 1956; Timberlake leg.; ex Isocoma acradenia ; UCRC • 1 ♀; Lancaster ; [34.69° N, 118.15° W]; 10 Oct. 1936; BBSL • 1 ♀; Olancha ; [36.28° N, 118.01° W]; 2 May 1927; Timberlake leg.; ex Salix exigua ; UCRC • 1 ♀; Saratoga Springs, Death Valley ; [35.681° N, 116.423° W]; 16–19 Jun. 1954; Belkin and McDonald leg.; LACM • 1 ♀; same location as for preceding; 23–24 Apr. 1955; LACM . – Idaho • 1 ♀; Twin Falls ; [42.56° N, 114.47° W]; 25 Aug. 1927; V.E. Romney leg.; MTEC. – Nevada • 1 ♀; Humboldt Co., Valmy ; [40.79° N, 117.13° W]; 25 May 1957; J.C. Hall leg.; UCDC • 1 ♀; Lincoln Co., Alamo ; [37.36° N, 115.16° W]; 31 Jul. 1958; F.D. Parker leg.; UCDC • 1 ♀; same location as for preceding; 30 Jul. 1968; F.D. Parker leg.; UCDC • 2 ♀♀; Nye Co., Beatty ; [36.91° N, 116.76° W]; 4 Aug. 1950; J.W. MacSwain leg.; ex Melilotus ; EMEC . – New Mexico • 1 ♀; Hidalgo Co., 9 mi. N of Cotton City; [32.21° N, 108.88° W]; 11 Aug. 1978; R.W. Brooks leg.; SEMC • 1 ♀, 1 ♂; 25 mi. W of Tularosa; [33.07° N, 106.45° W]; 1 Jul. 1940; D.E. Hardy leg.; SEMC • 1 ♀, 1 ♂; same location as for preceding; 1 Jul. 1940; L.C. Kuitert leg.; SEMC • 1 ♂; same location as for preceding; 1 Jul. 1940; R H. Beamer leg.; SEMC • 1 ♂; Estancia ; [34.76° N, 106.06° W]; 24 Jun. 1940; R.H. Beamer leg.; SEMC • 1 ♂; Moriarty ; [34.99° N, 106.05° W]; 24 Jun. 1940; R.H. Beamer leg.; SEMC . – Texas • 3 ♀♀; Bailey Co., Muleshoe Wildlife Refuge , Grassland 2 ; 33.9302° N, 102.4861° W; 15 Apr. 2013; S.J. Galdek leg.; BBSL • 1 ♀; Bailey Co., Muleshoe Wildlife Refuge , Prairie Dog 2 ; 33.9302° N, 102.7584° W; 15 Apr. 2013; S.J. Galdek leg.; BBSL . – Utah • 2 ♀♀; Emery Co., 1.5 mi. NE of Little Gilson Butte; [38.6° N, 110.58° W]; 1539 m a.s.l.; 23 Jul. 1981; Parker, Veirs and Griswold leg.; BBSL • 1 ♀; Emery Co., 2 mi. E of Little Gilson Butte; [38.59° N, 110.57° W]; 1554 m a.s.l.; 23 Jul. 1981; Parker, Veirs and Griswold leg.; BBSL • 1 ♀; Emery Co., above Little Wild Horse Canyon SW of Goblin Vly; [38.55° N, 110.82° W]; 1463 m a.s.l.; 26 Jul. 1983; Parker and Griswold leg.; BBSL • 4 ♀♀; Emery Co., Wild Horse Creek N of Goblin Vly; 38.5962° N, 110.7071° W; 1494 m a.s.l.; 25–28 Jul. 1983; Parker and Griswold leg.; BBSL • 1 ♀, 1 ♂; same location as for preceding; 21–23 Jul. 1981; Veirs, Parker and Griswold leg.; BBSL • 1 ♀; Kane Co., 1 mi. N of Little White Rock Canyon; 37.14° N, 111.8354° W; 9 Aug. 2002; S. Messinger leg.; ex Tamarix sp.; PCYU • 1 ♀; Kane Co., Tibbet Canyon ; 37.1606° N, 111.5392° W; ex Salsola paulsenii ; PCYU • 1 ♀; Tooele Co., 4.17 mi. SE of Wig Mt.; 40.276° N, 113.0068° W; 26 Sep. 2005; T. Griswold and K. Huntzinger leg.; PCYU • 1 ♀; Tooele Co., 4.6 mi. WSW of Little Granite Mtn.; 40.1755° N, 112.9218° W; 26 Sep. 2005; T. Griswold & K. Huntzinger leg.; PCYU . – Wyoming • 1 ♀; Big Horn Co., Lovell Local Training Area , Lovell ; [44.77° N, 108.3° W]; 1158 m a.s.l.; 11 Jul. 2000; B.C. Kondratieff, P.M. Pineda and H. Al-Dhafer leg.; CSUC • 1 ♂; Carbon Co., 8 mi. N of Baggs; [41.15° N, 107.66° W]; 16 Aug. 1963; N. and B. Marston leg.; AMNH .

Redescription

Female

See Gibbs (2010) for a complete redescription of the female (but note that the metasoma colour can vary from black to orange).

Male

COLOURATION. Head and mesosoma blue to blue-green; clypeus apical colour reddish brown; labrum reddish brown to orange; mandible orange with black basal spot and red tip; flagellum reddish brown dorsally, yellow-orange ventrally; pronotal lobe reddish brown; metasoma black or reddish brown with rims of terga and sterna narrowly translucent reddish brown and downcurved lateral areas of terga becoming narrowly transparent; legs reddish brown with femur-tibia joints, base and apex of tibiae, and tarsi yellow; tegula pale amber; wing membrane hyaline, veins with subcosta and costa apically brown, otherwise pale amber.

PUBESCENCE. Body hair colour white. Tomentum dense on head except postgena and between ocelli, mesosoma except pronotum anterior face, scutum and scutellum medially, and propodeum, T1–3 basally and laterally, and T4–6 throughout; sparse on propodeum posterolateral slope. Scutum hair densely plumose. Sterna hair short (1–1.5 OD), densely plumose, dense and erect. Wing hairs light, short and dense.

SURFACE SCULPTURE. Clypeus punctures moderately dense (i=1–2 pd), sculpture shiny; supraclypeal area punctures dense (i ≤ 1 pd), sculpture shiny; paraocular area punctures dense (i ≤ 1 pd), sculpture shiny; frons punctures dense (i <1 pd), sculpture shiny; vertex punctures dense laterally (i <1 pd), moderately sparse medially (i =1–2 pd), sculpture shiny; gena punctures moderately dense (i=1–2 pd), sculpture shiny; postgena sculpture shiny, becoming tessellate laterad of hypostomal carina; tegula punctures absent; scutum punctures sparse (i= 1–4 pd), becoming dense marginally (i ≤ 1 pd), sculpture shiny; scutellum punctures sparse (i =1–3 pd), sculpture shiny; metanotum sculpture shiny and finely, sparsely punctate (i= 1–3 pd); metapostnotum rugae strong, subparallel, not reaching margin, sculpture weakly imbricate; preëpisternum sculpture areolate; hypoepimeron punctures crowded (i=0 pd), sculpture shiny; mesepisternum punctures dense (i <1 pd), sculpture shiny; metepisternum sculpture lineate dorsally, areolate ventrally; propodeum lateral face punctures dense (i <1 pd), obscure, sculpture weakly imbricate; propodeum posterior face sculpture shiny and sparsely punctate (i =1–4 pd); T1 anterior face sculpture shiny; T1 dorsal surface punctures sparse (i =1–3 pd), sculpture shiny; T2 disc punctures moderately dense (i= 1–2 pd), becoming sparse apicomedially (i =1–3 pd), disc sculpture shiny, rim punctures minute, very sparse (i=3–6 pd), rim sculpture shiny.

STRUCTURE. Face length/width ratio 0.82 (± 0.02 SD). F1:pedicel length ratio 1.08 (± 0.21 SD); F2:F1 length ratio 1.75 (± 0.27 SD); F2 length/width ratio 1.26 (± 0.09 SD); F9 length/width ratio 1.11 (± 0.12 SD). Forewing with 3 submarginal cells; pronotal angle obtuse; tegula shape normal. Intertegular distance 0.9 (± 0.03 SD) mm. Scutum length/width ratio 0.77 (± 0.05 SD); scutum/scutellum length ratio 2.54 (± 0.16 SD); scutellum/metanotum length ratio 1.52 (± 0.11 SD); metanotum/metapostnotum length ratio 0.76 (± 0.08 SD). Propodeum lateral carinae not reaching dorsal margin; oblique carina absent. (n =5)

GENITALIA. As in Fig. 90K . Gonocoxite very broad, cashew-shaped. Gonostylus very large, boot-shaped, with a few long hairs. Retrorse lobe broad, ovoid, with dense short hairs concentrated at apex.

Range

Alberta south to Nuevo Leon and west to California ( Fig. 69 ).

Floral records

AMARANTHACEAE Juss. Salsola L. S. paulsenii Litv. • ASTERACEAE Giseke : Aplopappus • Ericameria : E. nauseosa (Pall. ex Pursh) G.L. Nesom & Baird : E. n. var. nauseosa (Pall. ex Pursh) G.L. Nesom & Baird • Gutierrezia : G. microcephala (DC.) A.Gray • Isocoma : I. acradenia (Greene) Greene • CLEOMACEAE Bercht. & J. Presl : Cleomella DC. C. obtusifolia Torr. & Frém. • Oxystylis Torr. & Frém. O. lutea Torr. & Frém. • Wislizenia Engelm. W. refracta Engelm. • FABACEAE Juss. Acacia : A. greggii A.Gray • Astragalus : A. lentiginosus Hook. • Melilotus • Prosopis : P. glandulosa

Torr. • POLYGONACEAE Juss. Eriogonum Michx. E. trichopes Torr. • ROSACEAE Juss. Prunus L. • SALICACEAE Mirb. Salix L. S. exigua Nutt. • TAMARICACEAE Link : Tamarix L. T. aralensis Bunge.

DNA barcodes

Six sequences available (BOLD process IDs: DLII676-07, DLII1090-07, DIAL1137-07, DLII1229-08, DLII1234-08, DLII1236-08). However, all are incomplete (<400 bp) and do not have an assigned BIN. Lasioglossum pallidellum differs from all other western red-tailed L. ( Dialictus ) by 2 fixed substitutions: 426(A) and 543(T) (Supplementary file 4).

Remarks

Lasioglossum pallidellum was redescribed by Gibbs (2010); however, neither the male nor the red-tailed form was known to him at that time. The male is described here for the first time. In addition, the known range of this species is expanded to Nuevo Leon and California.

Almost all specimens from the Mojave Desert are of the red-tailed form, and most of the rest are dark. The red-tailed form is especially abundant in and around Death Valley National Park. It is possible that there is a geographic barrier between the Mojave Desert and the rest of L. pallidellum ’s range, and the red and dark forms are distinct species. However, there are no other obvious morphological features distinguishing the two forms, and the geographic separation is not perfect. There are several red-tailed specimens and intermediate forms from eastern Utah, Coahuila, and Nuevo Leon, and a single dark female and two males from the Death Valley area. Along with the lack of high-quality DNA barcodes for both forms, the two-species hypothesis is difficult to test. Until more evidence to the contrary is found, it seems best to consider these a single species.

Figures

Fig. 67. Lasioglossum (D.) pallidellum (Ellis, 1914), red morph, ♀. A. Dorsal habitus. B. Lateral habitus. C. Face. D. Propodeum. E. Metasoma. Scale bars: 1 mm.

Fig. 68. Lasioglossum (D.) pallidellum (Ellis, 1914), dark morph, ♂. A. Dorsal habitus. B. Lateral habitus. C. Face. D. Propodeum. E. Metasoma. Scale bars: 1 mm.

Fig. 69. Georeferenced collection records of Lasioglossum (D.) pallidellum (Ellis, 1914) (black squares) and predicted distribution by maximum entropy ecological niche modeling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence.

Fig. 90. Male genitalia. A. Lasioglossum (D.) arenisaltans sp. nov. B. L. (D.) clastipedion sp. nov. C. L. (D.) clematisellum (Cockerell, 1904). D. L. (D.) hudsoniellum (Cockerell, 1919). E. L. (D.) julipile sp. nov. F. L. (D.) lilianae sp. nov. G. L. (D.) mesillense (Cockerell, 1898). H. L. (D.) meteorum sp. nov. I. L. (D.) miltolepoides sp. nov. J. L. (D.) minckleyi sp. nov. K. L. (D.) pallidellum (Ellis, 1914). L. L. (D.) pictum (Crawford, 1902). M. L. (D.) rufornatum sp. nov. N. L. (D.) spivakae sp. nov. O. L. (D.) testaceum (Robertson, 1897).P. L. (D.) vierecki (Crawford, 1904). Q. L. (D.) zephyrus (Smith, 1853). Genitalia are illustrated in dorsal view and positioned such that the gonostylus is parallel to the plane of vision. Retrorse lobes are also illustrated separately to the bottom left of each figure in lateral view, positioned parallel to the plane of vision.

Fig. 100. Forewings. A. Lasioglossum (D.) pallidellum (Ellis, 1914), ♂, with white hair, pale veins, and hyaline membrane. B. L. (D.) decorum sp. nov., ♀, with dark hair, dark veins, and lightly infuscated membrane. Scale bars: 1 mm.

Fig. 104. Propodeum. A. Lasioglossum (D.) pallidellum (Ellis, 1914), ♀, with metapostnotal rugae not reaching the posterior margin. B. L. (D.) clastipedion sp. nov., ♀, with metapostnotal rugae reaching the posterior margin. Scale bar: 0.25 mm.