Anthidiellum (Pycnanthidium) ayun Tran, Engel & Nguyen, 2023

Tran, Ngat Thi, Engel, Michael S., Nguyen, Cuong Quang, Tran, Duong Dinh & Nguyen, Lien Thi Phuong, 2023, The bee genus Anthidiellum in Vietnam: descriptions of five new species and the first male of Anthidiellum coronum (Hymenoptera, Megachilidae), ZooKeys 1144, pp. 171-196 : 171

Anthidiellum (Pycnanthidium) ayun Tran, Engel & Nguyen sp. nov.

Fig. 2A-H

Type material.

Holotype. Vietnam: ♀, Gia Lai, Mang Yang, Ayun, Kon Ka Kinh NP, 14°13'18"N, 108°19'02"E, alt. 907 m, 26.iii.2022 [26 March 2022], Lien Thi Phuong Nguyen, Ngat Thi Tran, Cuong Quang Nguyen leg. [IEBR].

Paratypes. Vietnam: 51♀♀, same data as holotype [41♀♀ in IEBR; 10♀♀ in AMNH]; 30♀♀, Gia Lai, Mang Yang, Ayun, Kon Ka Kinh NP, 14°12'11"N, 108°18'58"E, alt. 834 m, 25.iii.2022 [25 March 2022], Lien Thi Phuong Nguyen, Ngat Thi Tran, Cuong Quang Nguyen leg.; 4♀♀, Gia Lai, Mang Yang, Ayun, Kon Ka Kinh NP, 14°12'11"N, 108°18'58"E, alt. 834 m, 26.iv.2022 [25 April 2022], Lien Thi Phuong Nguyen, Ngat Thi Tran leg. [IEBR].

Diagnosis.

This female of this species is most similar to A. (P.) chumomray (vide infra), sharing with it the following characters: metatibia and metabasitarsus with a longitudinal carina on prolateral surfaces, and metasomal T2, supraclypeal area, pronotal lobe, and axillae black. It can be separated from that species easily by the following characters: mandible tridentate, teeth gradually longer and teeth sharp apically; clypeus approximately 1.4 × as broad as long and with trapezoidal yellow marking medially; mesoscutellum convex and bigibbous; paraocular area black.

Description.

♀: body length 7.0-7.5 mm (holotype = 7.5 mm). Forewing length 6.5-7.0 mm (holotype = 7.0 mm).

Structure. Head broader than long, approximately 1.2 × as broad as long (Fig. 2C ). Compound eyes about 2.3 × as long as broad, about 1.4 × genal width. Mandible tridentate, teeth gradually longer and sharp apically, interspace between first two teeth broad, second tooth nearly contiguous with third tooth (Fig. 2C ). Clypeus slightly convex medially, approximately 1.4 × as broad as long. Supraclypeal area slightly convex medially. Scape slender, about 3.1 × as long as broad, pedicel approximately 1.5 × as long as broad and about 1.3 × length of F1; F1 as long as broad and 1.5 × length of F2; F3-F5, F6-F7, F8-F9 subequal in length; F10 longest flagellomere, about 1.5 × as long as broad. Mesosoma approximately 1.2 × as broad as long; mesoscutum with medioapical margin slightly sharp; mesoscutellum convex, with mediolongitudinal depression apically giving bigibbous surface (Fig. 2D ). Prolateral surface of metatibia and metabasitarsus each with a longitudinal carina (Fig. 2G ). Metapretarsal arolium present (Fig. 2H ).

Sculpturing and texture. Outer surface of mandible with abundant, small, dense punctures except larger, wrinkled punctures on proximal half. Clypeus with dense, shallow punctures, puncture much smaller on apical margin than on disc. Paraocular area, supraclypeal area, and frons with large, coarse, contiguous punctures. Vertex with round, dense punctures of unequal sizes, puncture sizes smaller than those on frons. Mesoscutum with large, coarse, contiguous punctures; mesoscutellum with contiguous punctures of unequal sizes, puncture sizes smaller than those of mesoscutum (Fig. 2D ). Metasomal T1-T6 with small, round, dense punctures except punctures larger laterally.

Color. Body black except as follows: clypeus with trapezoid yellow marking except lateral and apical margins black (Fig. 2C ). Mesoscutum with short, thin yellow markings latero-anteriorly (Fig. 2D ). Metasomal T1 with yellow markings laterally; T3 basally with yellow band and large interrupted medially; T4 basally with yellow band and narrow interrupted medially (near as continuously in some paratypes); T5 basally with yellow band (Fig. 2A, B, F ).

Pubescence. Ventral margin of mandible with abundant, short, yellowish setae intermixed with long setae. Clypeus with short yellowish setae except sparse, erect, yellow setae on apical margin. Paraocular area, supraclypeal area, frons, and vertex with short yellowish setae. Diffuse tufts of long, dense, plumose, yellowish setae above antennal toruli. Mesoscutum and mesoscutellum with abundant short yellowish setae; mesoscutellum with long, erect, yellowish setae ventro-apically; propodeum with long, plumose, dense, yellowish setae. Prolateral surfaces of basitarsi and tarsi with dense, erect, yellowish setae; retrolateral surfaces of these same podites with tawny yellow setae. Metasomal T1-T6 with short, sparse, yellowish setae except short, yellowish setae on T6 apically; S2-S5 with long, dense, tawny yellow scopal setae.

♂: Latet.

Etymology.

The specific epithet is a toponym for type locality, the Ayun commune in Gia Lai Province. The name is treated as a noun in apposition.

Figures

Figure 2. Anthidiellum (Pycnanthidium) ayun Tran, Engel & Nguyen, sp. nov., holotype, female A dorsolateral oblique habitus B dorsal habitus C facial view D mesosoma in dorsal view E head and anterior mesosoma in profile, red arrow indicating omaular carina F dorsal oblique view of metasoma G prolateral surfaces of metatibia and metatarsus, with red arrows indicating longitudinal carinae H metapretarsal arolium (red arrow). Scale bars: 1 mm (A-G); 0.5 mm (H).