Lasioglossum (Dialictus) lepidii ( Graenicher, 1927 )

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 : 115-120

Lasioglossum (Dialictus) lepidii ( Graenicher, 1927)

Figs 39–41 , 96B , 119A

Halictus (Chloralictus) lepidii Graenicher, 1927: 204 (holotype, ♀, deposited in USNM, examined).

Lasioglossum (Chloralictus) lepidii – Michener 1951: 1114 (catalogue).

Dialictus tegularis – Mitchell 1960: 423 (in part, synonymy, redescription). — Hurd 1979: 1972 (in part, catalogue). — Moure & Hurd 1987: 134 (in part, catalogue).

Lasioglossum (Dialictus) tegulare – Krombein 1967: 466 (in part, catalogue).

Lasioglossum (Dialictus) lepidii – Gibbs 2009a: 22 (resurrection from synonymy, redescription). — Gibbs 2011: 25 , 32 (key to species), 130 (review).

Diagnosis

Females of L. lepidii have the tegula relatively small (reaching but not exceeding posterior margin of mesoscutum in dorsal view), with inner posterior margin straight and a blunt posterior angle, and sparsely punctate medially (IS = 1–3 PD); mesoscutum very dull, tessellate, and moderately densely punctate (IS = 1–2 PD) becoming dense on lateral and posterior margins (IS <1 PD); metapostnotum with very strong, coarse rugae reaching posterior margin and covering propodeum dorsolateral slope; mesepisternum with weak microsculpture and dense, distinct punctures (IS <1 PD); frons very finely punctate with very narrow, but distinct shiny interspaces between punctures; and T1–T3 very finely, minutely, obscurely punctate.

Females of L. lepidii are most similar to those of L. ellisiae , L. holzenthali sp. nov., L. puteulanum , and L. tegulare . Females of L. ellisiae have the tegula inner posterior margin sinuous and pointed posteriorly, and mesoscutum often shiny posteriorly. Females of L. holzenthali have the propodeum dorsolateral slope smooth, without rugae, and T1–T3 deeply and distinctly punctate. Females of L. puteulanum and L. tegulare have the mesepisternum very dull with crowded, indistinct punctures, and T1–T2 discs deeply and distinctly punctate.

Males of L. lepidii have the tegula relatively small (as in the female); metapostnotum shiny with strong anastomosing rugae; pleura finely and densely punctate (IS ≤ 1 PD), the preëpisternum and hypoepimeral area more so than mesepisternum; discs of T1–T2 minutely and moderately sparsely punctate (IS = 1–2 PD) and apical rims impunctate; face with very dense appressed tomentum below eye emargination obscuring most of surface; and mesothoracic spiracle deeply impressed.

Males of L. lepidii are most similar to those of L. diabolicum sp. nov., L. ellisiae , L. holzenthali sp. nov., L. puteulanum , and L. tegulare . All of these species have the preëpisternum, hypoepimeral area, and mesepisternum more coarsely and uniformly punctate, mesothoracic spiracle no more deeply impressed than surrounding punctures, and facial tomentum either less dense or less tightly appressed, appearing shaggier. Males of L. holzenthali , L. puteulanum , L. tegulare , and sometimes L. ellisiae have the disc of T2 more deeply and densely punctate (IS ≤ 1 PD). Males of L. holzenthali also have the apical rims of T1–T3 deeply and densely punctate (IS ≤ 1 PD).

Many specimens from tropical regions of Mexico, from Veracruz to Yucatán to Jalisco, are very similar to those of L. lepidii both morphologically and in DNA barcodes. These specimens appear to have the mesoscutum more sparsely punctate laterally (IS = 1–2 PD) and metapostnotum with finer, shallow rugae.

Etymology

Graenicher (1927) named this species after the plant Lepidium virginicum L., one of its hosts.

Material examined

Holotype UNITED STATES – Florida • ♀; South Miami ; [25.71° N, 80.29° W]; 20 Apr. 1927; USNM 41800 .

Other material

UNITED STATES – Florida • 2 ♀♀; Browfard Co., Hallandale Beach ; [25.98° N, 80.15° W]; 10 Dec. 1985; G.C. Eickwort leg.; CUIC • 2 ♀♀, 1 ♂; Collier Co., Collier-Seminole State Park ; [25.98° N, 81.6° W]; 25–26 May 1978; N.F. and J.B. Johnson leg.; CUIC • 1 ♂; Dade Co., Redlands ; [25.53° N, 80.49° W]; 21 Mar. 1987; Eickwort and Spielholz leg.; CUIC • 1 ♀; Highlands Co., Archbold Biological Station, Lake Placid ; [27.18° N, 81.35° W]; 2 Apr. 1984; B. Alexander leg.; CUIC • 1 ♀; Highlands Co., Highlands Hammock State Park ; [27.47° N, 81.55° W]; 13 Apr. 1964; G.C. Eickwort leg.; SEMC • 1 ♀; Leon Co., Tall Timbers Research Station , 3 mi. W of Iamonia; [30.66° N, 84.21° W]; 30 Mar. 1986; B. Alexander leg.; CUIC • 3 ♀♀, 4 ♂♂; Monroe Co., Bahia Honda Key, Bahia Honda State Recreation Area ; [24.662° N, 81.267° W]; 25 Mar. 1987; Eickwort and Spielholz leg.; CUIC • 2 ♀♀, 3 ♂♂; Monroe Co., Key Largo (city); [25.09° N, 80.44° W]; 22 Mar. 1987; Eickwort and Spielholz leg.; CUIC • 1 ♂; Monroe Co., Key Largo (east end); [25.27° N, 80.3° W]; 22 Mar. 1987; Eickwort and Spielholz leg.; CUIC • 3 ♀♀, 1 ♂; Monroe Co., Key Largo, Pennekamp State Park ; [25.125° N, 80.406° W]; 22 Mar. 1987; Eickwort and Spielholz leg.; CUIC • 4 ♀♀, 2 ♂♂; Monroe Co., Long Key, Long Key State Recreation Area ; [24.82° N, 80.81° W]; 23 Mar. 1987; Eickwort and Spielholz leg.; CUIC • 1 ♀; Pinellas Co., Fort Desoto County Park ; [27.62° N, 82.72° W]; 1 Jun. 1978; N.F. and J.B. Johnson leg.; CUIC • 3 ♀♀; Wakulla Co., 2 mi. N of Mack’s Landing, Apalachicola National Forest ; [30.12° N, 84.64° W]; 21 May 1981; G.C. Eickwort et al. leg.; CUIC • 2 ♀♀; Wakulla Co., Ochlockonee River State Park ; [30° N, 84.48° W]; 21 May 1981; G.C. Eickwort et al. leg.; CUIC • 1 ♂; Wakulla Co., Sopchoppy ; [30.06° N, 84.49° W]; 1 Apr. 1981; L.L. Pechuman leg.; CUIC • 1 ♀; Islamorada ; [24.92° N, 80.63° W]; 12 Apr. 1966; G. Eickwort leg.; SEMC • 1 ♂; Miami ; [25.8° N, 80.2° W]; 4 May 1927; S. Graenicher leg.; SEMC • 1 ♀; ibid.; 22 Jun. 192?; S. Graenicher leg.; SEMC • 1 ♀, 1 ♂; Westchester Miami ; [25.75° N, 80.33° W]; 31 Aug. 2006; J.A. Genaro leg.; PCYU .

Range

Florida ( Fig. 41 ).

Floral hosts (from Graenicher 1927)

AMARANTHACEAE : Telanthera R.Br. : T. floridana Chapm. [ambiguous] • ASTERACEAE : Pityopsis Nutt. : P. graminifolia (Michx.) Nutt. : P. g. var. tracyi (Small) Semple • BRASSICACEAE : Lepidium : L. virginicum L. • Warea Nutt. : W. carteri Small • MALVACEAE : Sida L.

DNA barcodes

Three confirmed sequences available (BOLD process IDs: DIAL863-06, DIAL865-06, DIAL867-06). There is a moderate amount of divergence within these sequences (0.61% maximum intraspecific p-distance). They are closest in terms of p-distance to L. pseudotegulare in the Nearctic (2.06% minimum interspecific p-distance) and an undescribed species in the Neotropics (1.23% minimum interspecific p-distance). Two fixed nucleotide substitutions distinguish L. lepidii from all other Nearctic species of the L. gemmatum complex: 372(A) and 552(G) (Supp. file 2).

Comments

It is possible that additional work will determine some or all of the Neotropical specimens to be L. lepidii , but at present the great geographic distance between the two populations is taken as sufficient justification for keeping them separate. If L. lepidii occurs in Mexico, then it would also be expected to occur either in Cuba or the Gulf of Mexico coast between Florida and Veracruz, but no specimens resembling L. lepidii have been seen from these areas.

A record on BOLD from Hidden Valley Ranch RV Park, New Mexico, also has a very similar DNA barcode to L. lepidii , but the voucher specimen has not been examined. This location is very arid desert habitat, in stark contrast to the wet tropical or subtropical habitats of other specimens, and it would be very unusual for L. lepidii to regularly occur here.

Figures

Fig. 39. Lasioglossum (D.) lepidii (Graenicher, 1927), ♀ (PCYU). A. Dorsal habitus. B. Lateral habitus. C. Face. D. Metasoma. Scale bars = 1 mm.

Fig. 40. Lasioglossum (D.) lepidii (Graenicher, 1927), ♂ (PCYU). A. Dorsal habitus. B. Lateral habitus. C. Face. D. Metasoma. Scale bars = 1 mm.

Fig. 41. Georeferenced collection records of Lasioglossum (D.) lepidii (Graenicher, 1927) (black squares) and predicted distribution by maximum entropy ecological niche modelling in Maxent (colour shading). Warmer colours indicate higher cloglog probability of occurrence. Because many coastal records lacked soil data, the model was generated without soil type as an environmental variable.

Fig. 96. Frons. A. Lasioglossum holzenthali sp. nov., ♀, roughened and dulled by crowded punctures without distinct interspaces. B. L. lepidii (Graenicher, 1927), ♀, smooth and shiny between punctures. Scale bars = 0.5 mm.

Fig. 119. Pleura. A. Lasioglossum lepidii (Graenicher, 1927), ♂, preëpisternum and hypoepimeron more finely punctate than mesepisternum. B. L. diabolicum sp. nov., ♂, preëpisternum and hypoepimeron as coarsely punctate as mesepisternum. Scale bars = 0.5 mm.