Anthidiellum (Ranthidiellum) ignotum Engel, 2009

Nalinrachatakan, Pakorn, Ascher, John S., Kasparek, Max, Traiyasut, Prapun, Thanoosing, Chawatat & Warrit, Natapot, 2023, A review of the anthidiine bees (Apoidea, Megachilidae) in Thailand, ZooKeys 1186, pp. 235-284 : 235

Anthidiellum (Ranthidiellum) ignotum Engel, 2009

Fig. 4A

Anthidiellum ignotum Engel, 2009: 30-34, figs 1-3. (♀) Holotype from Sakaerat Environmental Research Area, Nakhon Ratchasima Province, Thailand (SEMC, not examined).

Anthidiellum ignotum Engel: Soh et al. 2016: 55 (♀); Nalinrachatakan et al. 2021b: 164-167, figs 2, 4 (right), 5 (right) (♀, ♂ nov.).

Material examined.

(6♀, 1♂). Same specimens as in Nalinrachatakan et al. (2021b).

Record from iNaturalist

(2023). Thailand: Chiang Mai, Mueang District, Suthep Subdistrict (18°49'0.47"N, 98°55'26.81"E) uploaded by ‘jackychiangmai’ on 27 Oct. 2022 (observation id: 140223648).

Distribution.

Thailand (Chiang Mai, Nakhon Ratchasima, Phayao). The species is rare and appears to be endemic.

Floral association.

Plant family Amaranthaceae (possibly Achyranthes aspera L., commonly known as devil’s horsewhip), shown in the iNaturalist observation noted above. Also, the bee must mobilize plant resin as do other Ranthidiellum species (Pagden 1932; Pasteels 1972; Nalinrachatakan et al. 2021b).

Remarks.

Anthidiellum ignotum has distinct sexual dimorphism in which the male particularly had its base coloration brighter, with a noticeable black facial mark. More details on the presence of Ranthidiellum species in Thailand and its variation were discussed in Nalinrachatakan et al. (2021b).

Figures

Figure 4. Comparing specimens of Anthidiellum (Ranthidiellum) recently collected from Thailand, and its cleptoparasite A female Anthidiellum ignotum Engel, 2009 (BSRU-AA- 1249) B female paratype of Anthidiellum phuchongense Nalinrachatakan & Warrit, 2021 (BSRU-AB- 0159) C male paratype of cleptoparasite Stelis flavofuscinular Nalinrachatakan & Warrit, 2021 (BSRU-AB- 0156). Scale bar: 2 mm.