Anthidiellum (Ranthidiellum) ignotum Engel, 2009

Nalinrachatakan, Pakorn, Traiyasut, Prapun, Khongnak, Anupong, Muangkam, Manop, Ascher, John S. & Warrit, Natapot, 2021, The resin bee subgenus Ranthidiellum in Thailand (Megachilidae, Anthidiini): nesting biology, cleptoparasitism by Stelis, and new species, ZooKeys 1031, pp. 161-182 : 161

Anthidiellum (Ranthidiellum) ignotum Engel, 2009 Figs 2 , 4 (right), 5 (right)

Anthidiellum ignotum Engel, 2009: 30-34. (♀, holotype)

Anthidiellum ignotum Engel: Soh et al. 2016, 55. (♀)

Material examined

7 (6♀, 1♂). Thailand : Chiang Mai (new record), 2♀, 1♂ , Chiang Dao, Pha Dang National Park , Srisuwan Waterfall , Suan Dok Mai (19°37'49.88"N, 98°57'12.40"E, alt. 527.96 m), 19 Dec. 2018, N. Warrit et al. (CUNHM: BSRU-AA-6708, 6709). 1♀ , Mae Chaem District, Highway 1088, 9 Dec. 2016, N. Warrit et al. (CUNHM: BSRU-AA-2668). 1♀ , Samoeng , 13 Dec. 1992, Wichai [initially identified as " Apidae " by Wichit] (CMU-0013); 2♀ , Phayao, Mueang, Maeka , Phayao University , 1 Jun. 2012, W. Suwannarak et al. [CUNHM: BSRU-AA-1249, 1250, same specimens in Soh et al. (2016)] .

Distribution.

Thailand [Chiang Mai (Chiang Dao, Mae Chaem, and Samoeng Districts) and Phayao (Maeka District) Provinces; Nakhon Ratchasima Province, Sakaerat Environment Research Area (type locality from Engel (2009))].

Diagnosis.

This species can be distinguished from other Ranthidiellum by its remarkably bright ferruginous color, mostly without a black integument on their faces; tergites red-brown on marginal zone; T5 and T6 covered with pale-golden short tomentum; leg with reddish integument on coxa and femur of midleg and hindleg (see Engel 2009). Male with more extensive black maculation, especially on scutum and metasoma, whereas overall brighter than in female, predominantly on scutum; S4 gradulus incomplete (Fig. 5D ); gonoforceps bifid, with extended medio-lateral carina with acute sharp edge.

Description.

♂: Structure: Length 7.8 mm, head width 3.2 mm, intertegulae distance 2.2 mm, wingspan 15.2 mm.

Head. Overall prosomal coloration somewhat lighter than in female. Head lightly orange to yellow, gradually increasing in brightness ventrally, sparsely covered with bright yellow hairs. Maculation as in female but with dark contrast (Fig. 4H ): inverted heart-shaped mark on paraocular area making median Y-shape bridge connecting two large ovoid marks above antennal socket, extending upwards, concatenated at ocellar triangle, and forming a transverse band on vertex. Eye margin with narrow black mark on dorsal margin to about half of outer orbital margin. Clypeus bright yellow. Mandible yellow, shiny, apex not as broad as in females. Outer ridge conspicuous making upper area shallowly depressed. Teeth black, tridentate with large acute tooth at apex. Labrum dark yellowish, without conspicuous large hairs on surface as in female. Scape orange to yellow. Pedicel brown. Antennal flagellum orange brown on 1st and basal half of 2nd segments, other flagellomere pale light brown with pits on front and shiny yellow surface without pits posteriorly.

Mesosoma. Scutum largely black, with yellow inverted L-shaped band on anterolateral margin extending to fine paramedial line and abutting posterior margin, slightly curved medially. Scutellum and axilla yellow, median with black inverted triangular shape. Tegula dark yellow, somewhat translucent. Pronotal lobe pale yellow, strongly carinate to lamellate. Metanotum yellowish, laterally black. Propodeum black with small orange spot anteriorly around propodeal spiracle. Anterior surface of mesepisternum black, lateral surface yellow-orange with extensive black marks dorsally and in area adhering to metepisternum. Metepisternum yellow-orange, black on anterior and dorsal margin. Overall mesosoma covered with bright yellow hairs, except for pale white hairs on lower part of mesepisternum.

Wings. Forewing basally infuscated as in female, but with obvious hyaline patch covering parts of radial cell, 1st medial cell, and parts of 1st submarginal cell. Also, largely subhyaline on the marginal, submarginal, and 2nd medial cells.

Legs. Foreleg yellow-orange, with black mark on upper part of coxa, and small basal mark on both anterior and posterior surfaces of trochanter and femur. Midleg and hindleg largely black with some obscure red-brown infused, except for dark yellow on middle coxa, posterior area on hind coxa dark brown, apical area of middle trochanter, especially on posterior surface, yellow-brown, upper and lower parts of middle femur with obscure yellow-brown band, and middle tibia with outer brown-yellowish band. Middle and hind tarsi dark brown to black but gradually lighter towards end. Claw dark yellowish to brown, black on both apical and subapical tooth. Arolia present, hair bright yellow on foreleg, the rest overall black but white on dorsal part of coxa, femur, and trochanter of midleg and hindleg. Tarsal hair generally dark brown, gradually becoming bright yellow at the end.

Metasoma. Yellow-orange with thin black band infused at basal terga. Apical margin subhyaline showing black area of the former. T1 black on frontal surface defined with carina, extended to upper lateral surface. T2-T5 with small lateral dots and black thin stripes on basal part. T6 apically curved inward, forming conspicuous apical border with black surfaces on back (Fig. 4F ). T7 shield-like, black at margin, with median acute apex. Dorsal surfaces shiny and glabrous. Sternites overall yellow-orange except dark brown on S1. S4 (Fig. 5D ) margin extended as transparent membrane, median of margin with two small black teeth. S5 widely emarginated in trapezoid shape, lined with 83 black round teeth on its black apical margin (Fig. 5F ). S6 lined with black border slightly curved along basal margin, apical with broadly rounded projection. S7 thin, with laterally rounded angle. S8 inverted Y-shape (Fig. 5L ). Genitalia (Fig. 5N ) broad. Gonoforceps bifid with dorsal medio-lateral carina pointing as acute sharp edge. Penis valve simple. Hair bright yellow to white, black hair lining on lateral area of T1-T3 and covering some basal area of T4, extending more to the median on T3 but not abutted together.

Floral association.

Unknown.

Remarks.

Since a description of male A. (R.) ignotum is given here for the first time, variations in their color pattern are discussed later in the paper (see below).

Figures

Figure 2. Female Anthidiellum ignotum Engel, 2009 A, B lateral habitus and mesosoma of the " less melanized " individual (BSRU-AA- 1250) C, D lateral habitus and mesosoma of an individual with a black scutellum mark (BSRU-AA- 6709) E female faces and metasoma, showing variations of black infused stigma. From left to right: BSRU-AA- 2668, 1250, 1249, 6708, 6709, and CMU- 0013. Scale bars: 2 mm (A, B) or 1 mm (C, D).

Figure 4. Males of Anthidiellum phuchongensis sp. nov. holotype (BSRU-AB- 0161) (left) and A. ignotum Engel, 2009 (BSRU-AA- 6707) (right) A, B dorsal habitus C, E lateral habitus D, F metasoma G, H face. Scale bars: 2 mm (A, B, C, E) or 1 mm (D, F, G, H).

Figure 5. Genitalia and terminalia of male Anthidiellum phuchongensis sp. nov. holotype (BSRU-AB- 0161) (left) and A. ignotum Engel, 2009 (BSRU-AA- 6707) (right) A, B S 3 C, D S 4 E, F S 5 G, H S 6 I, J S 7 K, L S 8 M, N genitalia in dorsal habitus. Scale bars: 0.5 mm.