Lasioglossum (Dialictus) angelicum, Gardner & Gibbs, 2023

Gardner, Joel & Gibbs, Jason, 2023, Revision of the Nearctic species of the Lasioglossum (Dialictus) gemmatum species complex (Hymenoptera: Halictidae), European Journal of Taxonomy 858 (1), pp. 1-222 : 11-18

Lasioglossum (Dialictus) angelicum sp. nov.

urn:lsid:zoobank.org:act:7D4DB588-1714-46C7-AAC0-8E44E2AF44A5

Figs 3–5 , 76A , 78C , 86B , 87A , 90B , 92B , 93B , 110B

Diagnosis

Females of L. angelicum sp. nov. have the tegula very large (exceeding posterior margin of mesoscutum in dorsal view) and densely punctate (IS <1 PD), with inner posterior margin strongly concave and forming a posterior projection about the size of 1 lateral OD; scutellum densely punctate (IS <1 PD); metapostnotum shiny with strong anastomosing rugae reaching posterior margin; T1 shiny and distinctly, moderately densely punctate (IS = 1–2 PD), usually with some fine punctures extending onto apical rim; face short (length/width ratio ≤0.83); gena slightly shorter than eye in lateral view; and tegula and metasoma black. Often, the mesoscutum is relatively sparsely and coarsely punctate (posterior half with IS = 1–3 PD in centre and only 2–3 punctures present between posterior end of parapsidal line and lateral edge of mesoscutum) and shiny at least on lateral and posterior margins, but a few specimens have the mesoscutum dull and more densely punctate; these specimens are difficult to distinguish from L. helianthi . Females of L. angelicum sp. nov. are most similar to those of L. gaudiale , L. helianthi , L. pseudotegulare , and L. tegulariforme . Females of L. gaudiale and L. helianthi have the tegula slightly smaller (reaching but not exceeding posterior margin of mesoscutum in dorsal view) and sometimes more sparsely punctate (IS ≥ 1 PD laterally at midlength). In addition, females of L. gaudiale have the gena about as wide as eye in lateral view, scutellum often moderately sparsely punctate (IS = 1–2 PD), and metapostnotum usually with subparallel rugae not reaching posterior margin. Females of L. helianthi have the T1 anterior slope usually coriarious and mesoscutum posterior half entirely densely punctate (IS <1 PD). Females of L. pseudotegulare have the face slightly longer (length/width ratio ≥ 0.83) and metapostnotum dull with fine, subparallel rugae. Females of L. tegulariforme have T1 with an impunctate median line about 1 OD wide and mesoscutum posterior half entirely densely punctate (IS <1 PD). Some females of other, unknown species in the L. stictaspis species complex can be very similar, but all have the T1 disc more finely and sparsely punctate (IS = 1–4 PD) and/or coriarious, and often have the tegula and metasoma red-orange.

Males of L. angelicum sp. nov. have the tegula very large (as in the female); metapostnotum shiny with strong rugae; mesepisternum densely punctate (IS <1 PD) at least in ventral half; mesoscutum usually moderately densely punctate (IS = 1–2 PD); T1 shiny; discs of T1–T2 uniformly finely and moderately densely punctate (IS = 1–2 PD) with some punctures extending onto apical rims; face short (length/width ratio ≤ 0.86); and tegula black.

Males of L. angelicum sp. nov. are most similar to those of L. helianthi , L. pseudotegulare , and L. tegulariforme . Males of L. helianthi have the tegula smaller (not exceeding posterior margin of mesoscutum in dorsal view) with a narrow posterior point much smaller than 1 lateral OD and mesoscutum densely punctate (IS ≤ 1 PD). Males of L. pseudotegulare have the face slightly longer (length/width ratio usually>0.86) and discs of T1–T2 more densely punctate (IS ≤ 1 PD). Males of L. tegulariforme have the disc of T1 more sparsely punctate than T2, T1–T2 apical rims impunctate, and mesoscutum densely punctate (IS ≤ 1 PD). Some males of other, unknown species in the L. stictaspis species complex can be very similar, but usually have the mesepisternum ventral half more sparsely punctate (IS = 1–2 PD), T1 coriarious at base, or tegula red-orange. A few specimens may be morphologically indistinguishable and can only be separated by geography, DNA barcodes, or associated females.

Etymology

The specific epithet ʻ angelicum ʼ is a Latin adjective derived from the noun ʻ angelus ʼ (angel) plus the adjectival suffix ʻ -icum ʼ (having the quality of). It is a reference to the type locality of the Los Angeles basin, where this species is common. An appropriate translation would be the angelic sweat bee.

Material examined

Holotype UNITED STATES – California • ♀; Los Angeles Co., Expo Park Nature Gardens, NHMLA; 34.02° N, 118.29° W; elev. 54 m; 18–20 Jul. 2018; H. Hayes leg.; LACM ENT 376858 .

[Verbatim label: USA: CA, Los Angeles / Expo Park Nature Gardens, / NHMLA 34.02°N 118.29°W / 54m, 18–20 July 2018, / H. Hayes 408 // LACM ENT 376858 // BOLD / gard0266- CA / DLIII 216-20 // HOLOTYPE / Lasioglossum (Dialictus) angelicum Gardner and Gibbs ]

Paratypes UNITED STATES – California • 1 ♀; Los Angeles Co., 5700 Tobias Avenue ; 34.1739° N, 118.4518° W; elev. 209 m; 3 May 2018; S.B. Lerman leg.; ASUHIC LA-WF-2-BB-2 881 • 1 ♀; Los Angeles Co., 5831 Norwich Avenue ; 34.1767° N, 118.4611° W; elev. 212 m; 11 Apr. 2018; S.B. Lerman leg.; ASUHIC LA-XS-3-BB-1 496 • 1 ♀; Los Angeles Co., Atwater Village ; 34.114° N, 118.251° W; 28 May–4 Jun. 2014; Sidney Higgins leg.; LACM ENT 394539 • 1 ♂; Los Angeles Co., Ballona Wetlands near Playa del Rey; [33.97° N, 118.44° W]; 16 Jun. 1981; R.R. Snelling leg.; CUIC • 4 ♀♀, 1 ♂; Los Angeles Co., Chatsworth ; 34.26° N, 118.601° W; 1–8 May 2017; LACM • 21 ♀♀, 5 ♂♂; ibid.; 1–8 Jul. 2017; LACM • 3 ♀♀, 5 ♂♂; Los Angeles Co., Claremont ; 34.0894° N, 117.7111° W; 1–8 Jul. 2016; LACM • 4 ♀♀, 3 ♂♂; ibid.; 1–8 Aug. 2016; LACM • 1 ♀; Los Angeles Co., Eagle Rock ; 34.129° N, 118.215° W; 3–10 May 2014; Eric Keller leg.; LACM ENT 394537 • 1 ♀; Los Angeles Co., Eagle Rock ; 34.13° N, 118.23° W; elev. 169.9 m; 15–21 Jul. 2018; Hannah Hayes leg.; LACM ENT 380968 • 1 ♀; Los Angeles Co., Expo Park ; 34.018° N, 118.289° W; elev. 55 m; 30 May–6 Jul. 2014; D. Pentcheff, L. Gonzalez leg.; LACM ENT 394536 • 2 ♂♂; same locality as for holotype; 18 Jul. 2018; Hannah Hayes leg.; LACM ENT 376863 , 376871 • 1 ♀; same locality as for holotype; 13–15 Aug. 2018; Hannah Hayes leg.; LACM ENT 381174 • 14 ♀♀, 3 ♂♂; Los Angeles Co., Gardena ; 33.876° N, 118.288° W; 2–9 Oct. 2018; LACM • 5 ♀♀, 1 ♂; ibid.; 1–8 Nov. 2018; LACM • 9 ♀♀, 1 ♂; Los Angeles Co., Gardena ; 33.8843° N, 118.2866° W; 1–8 Jul. 2016; LACM • 1 ♂; Los Angeles Co., Glendale ; 34.159° N, 118.247° W; 31 May–7 Jun. 2014; Celeste Armstrong leg.; LACM ENT 394543 • 1 ♀; Los Angeles Co., Mid-City ; 34.047° N, 118.334° W; 31 May–7 Jun. 2014; Sharon Oxborough leg.; LACM ENT 394538 • 2 ♂♂; Los Angeles Co., Pasadena ; [34.15° N, 118.14° W]; 24 Jun. 2000; John S. Ascher leg.; AMNH • 2 ♀♀; Los Angeles Co., Pasadena , Arroyo Park; [34.15° N, 118.165° W]; 7 Mar. 2001; John S. Ascher leg.; AMNH • 1 ♀; Los Angeles Co., Silverlake ; 34.093° N, 118.274° W; 31 May–7 Jun. 2014; Walter Renwick leg.; LACM ENT 394540 • 11 ♀♀; Los Angeles Co., Torrance ; 33.8712° N, 118.331° W; 13–23 Jul. 2017; LACM • 6 ♂♂; ibid.; 13–23 Jul. 2017; LACM • 1 ♂; Los Angeles Co., University Park ; 34.034° N, 118.281° W; 28 May–4 Jun. 2014; Peggy Hentschke leg.; LACM ENT 394542 • 22 ♀♀, 11 ♂♂; Los Angeles Co., Valley Village ; 34.171° N, 118.398° W; 1–8 Jul. 2017; LACM • 3 ♀♀, 1 ♂; Riverside Co., Norco ; 33.912° N, 117.5702° W; 1–8 Jun. 2016; LACM • 1 ♀; San Diego Co., 2 km E of Pine Valley ; 32.8247° N, 116.5042° W; elev. 1300 m; 31 May–5 Jun. 2002; F.D. Parker, M.E. Irwin leg.; BBSL FDP195086 • 1 ♀; Santa Barbara Co., CCBER Greenhouse , 61M NW Parking Lot 38 , UCSB; 34.4209° N, 119.8581° W; 14 May 2019; CCBER UCSB-IZC00036859 • 1 ♀; Santa Barbara Co., Isla Vista , San Joaquin Restoration Project; 34.4177° N, 119.8655° W; 8–10 Mar. 2016; Elaine Tan leg.; CCBER UCSB-IZC00034561 • 1 ♀; Santa Barbara Co., UCSB North Parcel ; 34.4224° N, 119.8794° W; 7 Feb. 2019; CCBER UCSB-IZC00036899 • 1 ♂; Ventura Co., Santa Clara River ; 34.3891° N, 118.8853° W; 20 May 2019; CCBER UCSB-IZC00037014 • 1 ♀; Newport Beach ; [33.62° N, 117.93° W]; 19 Aug. 1920; Philip H. Timberlake leg.; ex anise; UCRC ENT 525678 • 1 ♂; Riverside ; [33.97° N, 117.32° W]; 31 Aug. 1924; Philip H. Timberlake leg.; ex on wing; UCMC • 1 ♀; ibid.; 10 Feb. 1925; Philip H. Timberlake leg.; ex Encelia farinosa ; UCMC • 1 ♀; San Diego ; [32.71° N, 117.16° W]; 22 Apr. 2004; DB leg.; WRME 518949 .

Description

Female

COLOURATION. Head and mesosoma blue to blue-green; clypeus apex black; labrum black; mandible orange with black base and red apex; flagellum black dorsally, orange ventrally. Pronotal lobe black; legs black with femur-tibia joints and tarsi dark reddish brown; tegula dark reddish brown; wing membrane hyaline, veins with subcosta dark brown, otherwise lighter brown. Metasoma black with rims of terga and sterna broadly translucent yellow.

PUBESCENCE. Body pile colour white to pale yellow. Tomentum dense on lower paraocular area, gena adjacent to compound eye, pronotal collar and lobe, space between pronotal lobe and tegula, T2–T3 basolaterally, and T4 throughout. Mesoscutum pubescence thin to moderately plumose. Wing setae dark, short and dense. Acarinarial fan complete, dense. T2 fringes dense, T3 fringes dense.

SURFACE SCULPTURE. Clypeus shiny, with punctures moderately sparse (IS = 1–2 PD), becoming larger in apical half; supraclypeal area shiny, with punctures moderately dense (IS = 1–2 PD); paraocular area shiny, with punctures dense (IS <1 PD), sparser around antenna socket (IS ≤ 1 PD); frons reticulate, with punctures fine, crowded (IS = 0 PD); vertex shiny, with punctures dense laterally (IS <1 PD), sparse medially (IS = 1–3 PD); gena shiny, with punctures fine, sparse (IS = 1–3 PD); postgena lineolate, becoming shiny anteriorly. Tegula punctures dense (IS <1 PD); mesoscutum weakly tessellate, with punctures moderately dense (IS = 1–2 PD), becoming dense on lateral and posterior margins (IS <1 PD); scutellum weakly tessellate, with punctures dense marginally (IS <1 PD), moderately sparse submedially (IS = 1–2 PD); metapostnotum shiny, becoming tessellate posteriorly, with rugae strong, anastomosing, reaching posterior margin; preëpisternum rugulose; hypoepimeron shiny, with punctures crowded (IS = 0 PD); mesepisternum imbricate, with punctures dense (IS ≤ 1 PD); metepisternum weakly rugulose; propodeum lateral surface weakly tessellate, becoming weakly rugulose dorsally and anteriorly, posterior surface weakly tessellate. T1 anterior slope shiny, disc shiny, with punctures fine, moderately dense (IS = 1–2 PD), absent in large subapicolateral boss and on rim; T2 disc shiny, with punctures fine, moderately dense (IS = 1–2 PD), apical rim shiny, with punctures minute, sparse (IS = 1–4 PD).

STRUCTURE. Face length/width ratio 0.81 (± 0.02 SD); clypeus apicolateral denticles low rounded knobs; gena/eye width ratio 0.88 (±0.07 SD). Pronotal angle slightly obtuse, nearly right-angled; intertegular span 0.85 (±0.05 SD) mm; mesoscutum length/width ratio 0.9 (± 0.03 SD); mesoscutum/scutellum length ratio 2.87 (± 0.08 SD); scutellum/metanotum length ratio 1.62 (± 0.1 SD); metanotum/metapostnotum length ratio 0.77 (± 0.06 SD); forewing with 3 submarginal cells; tegula enlarged, exceeding posterior margin of mesoscutum; inner margin concave; tegula length 0.46 (±0.03 SD) mm, width 0.23 (± 0.02 SD) mm; propodeum lateral carinae not reaching dorsal margin; oblique carina strong, straight. T2 depressed apical rim less than 50% of tergum. (n = 10)

VARIATION. The mesoscutum is occasionally completely tessellate and/or densely punctate in posterior half (IS ≤ 1 PD); the mesepisternum can vary from shiny to dull and imbricate; the T1 anterior slope is sometimes weakly coriarious; and the T1 apical rim is often punctate below the subapicolateral boss.

Male

COLOURATION. Head and mesosoma blue to blue-green; clypeus apex black; labrum black; mandible orange, becoming red at apex and black at base; flagellum black dorsally, light brown or orange ventrally. Pronotal lobe black; legs black with tarsi dark brown; tegula black; wing membrane hyaline, veins dark brown. Metasoma black with depressed apical rims of terga and sterna translucent brown.

PUBESCENCE. Body pile colour white. Tomentum dense on face below eye emargination, pronotal angle and lobe, and space between pronotal lobe and tegula; sparse on metepisternum. Mesoscutum pubescence simple to sparsely plumose. Wing setae dark, short and dense. Sterna pubescence short (0.5–1.5 OD), moderately plumose, sparse.

SURFACE SCULPTURE. Clypeus shiny, with punctures dense (IS <1 PD); supraclypeal area shiny, with punctures dense (IS ≤ 1 PD); paraocular area shiny, with punctures dense (IS <1 PD); frons reticulate, with punctures crowded (IS = 0 PD); vertex shiny to imbricate, with punctures crowded laterally (IS = 0 PD), moderately dense medially (IS = 1–2 PD); gena shiny anteriorly, imbricate-lineate posteriorly, with punctures dense anteriorly (IS ≤1 PD), obscure posteriorly; postgena imbricate-lineate, becoming shiny anteriorly. Tegula punctures crowded (IS = 0 PD), sometimes slightly sparser medially; mesoscutum shiny, becoming weakly tessellate anteromedially, with punctures moderately dense (IS = 1–2 PD), becoming crowded marginally (IS = 0 PD); scutellum shiny, with punctures dense (IS <1 PD), becoming sparser medially (IS = 1–2 PD); metanotum areolate; metapostnotum shiny to finely reticulate, with rugae strong, subparallel, reaching posterior margin; preëpisternum areolate; hypoepimeron shiny, with punctures crowded (IS = 0 PD); mesepisternum shiny, with punctures dense (IS <1 PD); metepisternum areolate; propodeum lateral surface weakly rugulose, with punctures dense (IS <1 PD), posterior surface rugulose, becoming shiny and densely punctate medially (IS <1 PD). T1 anterior slope shiny, disc shiny, with punctures fine, moderately sparse (IS = 1–2 PD), absent in large subapicolateral boss and on rim medially; T2 disc shiny, with punctures fine, moderately sparse (IS = 1–2 PD), apical rim shiny, with punctures absent.

STRUCTURE. Face length/width ratio 0.83 (±0.02 SD); gena/eye width ratio 0.77 (± 0.06 SD). Pronotal angle obtuse; intertegular span 0.71 (± 0.04 SD) mm; mesoscutum length/width ratio 0.95 (± 0.03 SD); mesoscutum/scutellum length ratio 2.8 (±0.14 SD); scutellum/metanotum length ratio 1.76 (± 0.14 SD); metanotum/metapostnotum length ratio 0.7 (± 0.09 SD); forewing with 3 submarginal cells; tegula enlarged, exceeding posterior margin of mesoscutum in dorsal view; inner posterior margin strongly concave, with broadly rounded projection angled toward axilla posteriorly; tegula length 0.44 (± 0.02 SD) mm, width 0.22 (± 0.01 SD) mm; propodeum lateral carinae not reaching dorsal margin; oblique carina absent. (n = 10)

GENITALIA. As in Fig. 76A . Gonocoxite about 1.8 times as broad as gonostylus. Gonostylus weakly boot-shaped, with a small sharply angled concavity on outer margin and straight on inner margin, with sparse short setae apically. Penis valves parallel, with moderately long appressed setae dorsolaterally in basal half. Retrorse lobe rounded, about 2.75 times as long as broad, with sparse short setae on apical and dorsal margins.

VARIATION. The mesoscutum punctation can vary from mostly dense (IS ≤ 1 PD) to sparse (IS = 1–3 PD), the mesepisternum dorsal half is sometimes more sparsely punctate (IS = 1–2 PD), and the T2 apical rim is often punctate on the centre of the basal margin.

Range

Los Angeles basin and south along the Pacific coast to San Diego, west to Malibu ( Fig. 5 ).

Floral hosts

APIACEAE Lindl. : Pimpinella L.: P. anisum L. • ASTERACEAE Bercht. & J.Presl : Encelia Adans. : E. farinosa A.Gray ex Torr.

DNA barcodes

Five confirmed sequences available (BOLD process IDs: DLIII214-20, DLIII215-20, DLIII216-20, DLIII223-20, NCBEE465-21). These sequences are identical (0% maximum intraspecific p-distance). They are closest in terms of p-distance to L. diabolicum sp. nov. (1.84% minimum interspecific p-distance). Four fixed nucleotide substitutions distinguish L. angelicum sp. nov. from all other Nearctic species of the L. gemmatum complex: 222(C), 237(A), 420(G), and 525(C) (Supp. file 2).

Figures

Fig. 3. Lasioglossum (D.) angelicum sp. nov., ♀, holotype (LACM ENT 376858). A. Lateral habitus. B. Dorsal habitus. C. Face. D. Metasoma and propodeum. Scale bars = 1 mm.

Fig. 4. Lasioglossum (D.) angelicum sp. nov., ♂ (LACM ENT 394542). A. Dorsal habitus. B. Lateral habitus. C. Face. D. Metasoma. Scale bars = 1 mm.

Fig. 5. Georeferenced collection records of Lasioglossum (D.) angelicum sp. nov. (black squares) and predicted distribution by maximum entropy ecological niche modelling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence.

Fig. 76. Male genitalia 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. A. Lasioglossum (D.) angelicum sp. nov.B. L. (D.) coactus (Cresson, 1872). C. L. (D.) deludens sp. nov. D. L. (D.) diabolicum sp. nov.E. L. (D.) gaudiale (Sandhouse, 1924). F. L. (D.) gloriosum sp. nov. (the retrorse lobe was not visible for illustration). G. L. (D.) helianthi (Cockerell, 1916). H. L. (D.) holzenthali sp. nov. I. L. (D.) indagator sp. nov. J. L. (D.) magnitegula sp. nov. K. L. (D.) perparvum (Ellis, 1914). L. L. (D.) profoundum sp. nov. M. L. (D.) pseudotegulare (Cockerell, 1896). N. L. (D.) rufodeludens sp. nov. This genital capsule was damaged during dissection and some details may be slightly distorted.O. L. (D.) stictaspis (Sandhouse, 1923) (holotype) (reproduced from Gardner & Gibbs 2022). P. L. (D.) tegulariforme (Crawford, 1907) (reproduced from Gardner & Gibbs 2022). Scale bars = 0.25 mm.

Fig. 78. Mesoscutum pubescence. A. Lasioglossum perparvum (Ellis, 1914), ♀, lateral view, with pubescence very short and sparse. B. L. magnitegula sp. nov., ♀, dorsal view, with pubescence very short and sparse. C. L. angelicum sp. nov., ♀, lateral view, with pubescence long and dense. D. L. deludens sp. nov., ♀, dorsal view, with pubescence long and dense. Scale bars = 0.5 mm.

Fig. 86. T2–T3.A. Lasioglossum coactus (Cresson, 1872), ♀, with complete subapical band of tomentum on T3 and deep and dense punctures on disc of T2 contrasting with sparsely punctate apical rim. B. L. angelicum sp. nov., ♀, T3 without complete subapical band of tomentum and fine T2 punctures not contrasting across premarginal line. Scale bars = 0.5 mm.

Fig. 87. Tegulae. A. Lasioglossum angelicum sp. nov., ♀, large with inner posterior margin concave and distinct posterior projection (outline and arrow). B. L. diabolicum sp. nov., ♀, small with inner posterior margin nearly straight and no posterior projection (outline). Scale bars = 0.5 mm.

Fig. 90. T1 disc.A. Lasioglossum tegulariforme (Crawford, 1907), ♀, with median impunctate line about 1 OD wide (brackets). B. L. angelicum sp. nov., ♀, uniformly punctate. Scale bars = 0.5 mm.

Fig. 92. T1 anterior slope. A. Lasioglossum puteulanum Gibbs, 2009, ♀, coriarious. B. L. angelicum sp. nov., ♀, smooth and shiny. Scale bars = 0.5 mm.

Fig. 93. Mesoscutum. A. Lasioglossum tegulariforme (Crawford, 1907), ♀, finely and very densely punctate. B. L. angelicum sp. nov., ♀, coarsely and moderately sparsely punctate. Scale bars = 0.5 mm.

Fig. 110. Tegulae. A. Lasioglossum helianthi (Cockerell, 1916), ♂, with smaller posterior projection (outline on left) barely exceeding mesoscutum posterior margin. B. L. angelicum sp. nov., ♂, with larger posterior projection (outline on left) clearly exceeding mesoscutum posterior margin. The white circle corresponds to 1 lateral OD. Scale bars = 0.5 mm.