A review of the anthidiine bees (Apoidea, Megachilidae) in Thailand Author Nalinrachatakan, Pakorn https://orcid.org/0000-0001-7962-5844 Center of Excellence in Biology and Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Author Ascher, John S. https://orcid.org/0000-0002-7887-2461 Insect Diversity Lab, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4 S 3 Level 4, 117558 Singapore, Singapore Author Kasparek, Max https://orcid.org/0000-0002-5604-6791 Moenchhofstr., 16, 69120 Heidelberg, Germany Author Traiyasut, Prapun https://orcid.org/0000-0002-7114-0890 Program in Biology, Faculty of Science, Ubon Ratchathani Rajabhat University, Ubon Ratchathani 34000, Thailand Author Thanoosing, Chawatat https://orcid.org/0000-0002-4228-748X Center of Excellence in Biology and Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand & Department of Life Sciences, Natural History Museum, Cromwell Road, London SW 7 5 BD, UK Author Warrit, Natapot https://orcid.org/0000-0002-6338-1782 Center of Excellence in Biology and Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand ich108@hotmail.com text ZooKeys 2023 2023-12-19 1186 235 284 http://dx.doi.org/10.3897/zookeys.1186.95203 journal article http://dx.doi.org/10.3897/zookeys.1186.95203 1313-2970-1186-235 4417B04CBD9449DC95133B89EB6E5F72 94A58877E81E514DB42E312A2327809C Anthidiellum (Ranthidiellum) apicepilosum (Dover, 1929) Fig. 3 Dianthidium apicepilosum Dover, 1929: 55 (♀). Holotype from "Khao Ram, Siam" [= Nakhon Si Thammarat, Thailand] (NHMUK, examined); photograph available at https://data.nhm.ac.uk/object/17eba820-1a7d-4175-a9f8-f367b04dbf94/1632960000000). Dianthidium apicepilosum Dover: Pagden 1934 : 490-492 (♂ nov.). Anthidiellum (Ranthidiellum) apicepilosum (Dover): Pasteels 1969 : 48-49. Anthidiellum ( Rhanthidiellum [sic!]) Rhanthidiellum apicepilosum (Dover): Pasteels 1972 (redescription): 103-106, unjustified emendation of Ranthidiellum Pasteels, 1969. Material examined. 1♀ . Khao Ram , Siam [= Thailand : Nakhon Si Thammarat : Ronpibun, Khao Ramrome], 750-1200 [possibly altitude], 24 Feb. 1922 , Anthidium apicepilosum Dover , 1926 ( holotype NHMUK: 014026685) . Distribution. Malaysia (Negeri Sembilan, Penang, Selangor), Thailand (Nakhon Si Thammarat). The species is rarely found, hence the records are based on the original designation ( Dover 1929 ) and the additional report of their nest ( Pagden 1934 ) Diagnosis. Anthidiellum apicepilosum has a black body with distinct brownish coloration disrupted. Since only the female is known, the most comparable characters include the following: clypeus, scape, lower paraocular area, tegula, axilla, and the margin of scutellum brownish; scutum black; wing base conspicuously dark brown, clearly contrasting to apical hyaline parts on 1st submarginal cells; T1-T5 with reddish to brownish ferruginous apical band that becomes wider on the rear segments; T6 black; the rear of the metasoma covered with yellowish hairs; foreleg light brownish, generally brighter than in midleg and hindleg, which are almost black on their tibia and basitarsus. According to Pagden (1934) and Pasteels (1972) , the male is superficially similar to the female but has lighter ferruginous leg parts especially on midleg and hindleg; S5 with a marginal black comb (> 60 teeth), gonoforceps bifid as in other Ranthidiellum species. Remarks. This is the first species of Ranthidiellum that has been documented for its nesting biology ( Pagden 1934 ). In morphology, the species is very close to Anthidiellum rufomaculatum (Cameron, 1902) with a minor difference in that the female holotype of " Protoanthidium rufomaculatum " [= Anthidiellum rufomaculatum , female from Kuching, Sarawak, Malaysia] has more minute paraocular marks, more slender marginal bands on its axilla and scutellum, and a reddish black translucent band present basally on the black integument of T1-T5. However, to confirm the status, there is no certain evidence that the males described by Pagden (1934) are the exact Anthidiellum apicepilosum , even though the locality of Bakit Kutu, Selangor, is adjacent to the Negeri Sembilan, where the female paratype was caught (further discussion in Nalinrachatakan et al. 2021b ). Figure 3. Female holotype of Anthidiellum apicepilosum (Dover, 1929) (NHMUK: 014026685) A lateral habitus B face C rear view of metasoma showing T6 D dorsal view and labels, modified from NHMUK data portal. Scale bars: 2 mm ( A ); 1 mm ( B, C ).