Rhynostelis plesiognatha, Parizotto & Melo, 2020

Parizotto, Daniele R. & Melo, Gabriel A. R., 2020, Revision of the rare anthidiine bee genus Rhynostelis Moure & Urban (Hymenoptera, Apidae), Revista Brasileira de Entomologia (e 20190029) 64 (2), pp. 1-7 : 5-6

Rhynostelis plesiognatha sp. nov.

( Figs. 6-10 )

Stelis (Hoplostelis) tuberculata, nomen nudum. Dominique,1898: 61.

Comments. The female from Manaus, Brazil, previously identified as R. multiplicata in Moure and Urban (1995), and a pair of specimens from Belém, Pará, Brazil, identified as R. multiplicata by Parizotto and Urban (2012), correspond to a distinct species newly described here. The female specimen from French Guiana (examined by photos) mentioned in Dominique (1898) under the nomen nudum “Stelis tuberculata” and placed by Rasmussen et al. (2007) and Urban and Moure (2007) under R. multiplicata also belongs to this new species. The male was described and illustrated by Parizotto and Urban (2012) as R. multiplicata .

Diagnosis. This new species is more similar to R. multiplicata by the color pattern; the axillae rounded; scutellum with shallow posterior emargination ( Fig.8 ) and tergal pilosity brown to black ( Figs. 9 and 14 ). The females of R. plesiognatha sp. nov. can be easily distinguished by their less modified clypeus, provided only with a short tubercle on the upper margin and lacking the strongly raised beak-like projection of R. multiplicata , and by its simpler mandible, with a short truncate projection near the anterior articulation ( Figs. 6 and 7 ).

Description. Holotype female. Approximate body length 16 mm; forewing length 12.2 mm; head width 5.3 mm; eye length 3.1 mm.

Color. Head integument yellow except: distal margin of mandible and apical tooth blackish; black band on supraclyeal area extending upward to vertex ( Figs. 6 and 7 ). Pronotal lobe yellow; scutum black with reverse U-shaped yellow maculae almost reaching the scutoscutellar suture; scutellum with two large subapical yellow bands; axilla yellow. Mesepisternum yellow, with a little black spot medially. Tegula reddish brown, with a yellow spot anteriorly; fore wing membrane brown infumated throughout. Legs predominantly yellow ( Figs. 8 and 10 ). Terga black with yellow maculae; yellow band on T1 angled at middle; yellow band on T2-T5 wider and slightly interrupted medially; T6 with two large yellow spots ( Fig. 9 ). Three basal sterna yellow, with large translucent margin; S4 yellow with dark infuscated area medially; S6 black with two lateral yellow spots. Pubescence. Head and mesosoma with mostly light yellowish ferruginous pilosity, shorter than ocellar diameter.Pubescence longer and denser between ocelli, above antennal sockets and lower margin of clypeus. Hairs of mesepisternum slightly longer and denser than those on mesoscutum ( Fig. 8 ). Pilosity of terga as in R. multiplicata . Sculpturing. Head with shallow and coalescent punctures; smaller and fine on disc of clypeus. Mesoscutum with deeper and smaller punctures than those on head. Gibbous area of mesepisternum with punctures sparser than on mesoscutum. Punctures of terga fine and shallow; punctures on yellow bands larger and sparser than those on black areas ( Fig. 9 ); distal tergum with larger punctures.

Structure. Mandible with bifurcated condylar carina, antero-basal projection short and truncate; supraclypeal area not raised, except for the medial carina; clypeus with a small medial tubercle on its upper margin ( Figs. 6 and 7 ).

Paratype male. Approximate body length 13.3; forewing length 10.5; head width 4.0; head length 3.77; eye length 2.5. Color. Integumental marks as in the female except for: T2-T5 with yellow band wider medially and slightly interrupted on T2-T3; T5 with yellow band emarginated at middle on posterior margin; T6 with broad yellow band, wider medially; T7 with subapical yellow band with blackish margin.Two basal sterna yellow, with large translucent margin; S3-S5 yellow with dark infuscated area on apical half; S6 with a median black spot. Pubescence and Sculpturing. As in female except for a more conspicuous pilosity in paraocular area and coxae. Structure. Mandibles with only apical tooth; condylar carina distinctly raised, almost laminated; T7 short and sinuous at middle; S6 with large lateral laminar projections.

Type material. Holotype female ( DZUP): Pará, Belém, “IPEAN [ Instituto de Pesquisas e Experimentação Agropecuária do Norte, Belém] \ 105-1 \ EU”. The holotype is in perfect condition, except for the broken antennae, which have been glued to one of the specimen labels . Paratypes: one male ( DZUP), Pará, Belém “IPEAN [ Instituto de Pesquisas e Experimentação Agropecuária do Norte, Belém] \ 105-2 \ EU” ; one female ( DZUP), Amazonas, Manaus, “Proj.[Project] DBFF.WWF\ Manaus-AM\ Brasil 04/11/89 / M. B. V. Garcia ” .

Distribution. This species is known from Brazil (Amazonas and Pará) and French Guiana.

Etymology. The species is named in reference to its less complex mandible, in comparison to the other species, from the Greek plesios, near, and gnathos, mandible.

Figures

Figures 6-10. Rhynostelis plesiognatha sp. nov., holotype female. 6, head, frontal view; 7, head and mesosoma, lateral view; 8, head and mesosoma, dorsal view; 9, metasoma, dorsal view; 10, habitus, lateral view. Scale line = 2.0 mm.

Figures 11-15. Rhynostelis multiplicata, female specimen from Suriname. 11, head, anteroventral view; 12, head, posterodorsal view; 13, habitus, dorsal view; 14, metasoma, dorsal view; 15, habitus, lateral view. Scale line = 2.0 mm (Figs. 11, 12 and 14). Scale line = 5.0 mm (Figs.13 and 15).