Rhynostelis Moure and Urban, 1995

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 : 2-4

Rhynostelis Moure and Urban, 1995

( Figs. 1-21 )

Type species: Anthidium multiplicatum Smith, 1879 by original designation.

Rhynostelis was described as a monotypic cleptoparasitic genus based on only two females originating from the Amazonas state, in northern Brazil: a female collected by Henry Bates in São Paulo de Olivença and described as male by Smith (1879) under the name Anthidium multiplicatum, and a second female that emerged from a nest of Eufriesea built within the walls of a termite nest in Manaus ( Moure and Urban, 1995). Moure and Urban (1995) assumed that the female from Manaus belonged to the same species based on the manuscript note made by Moure of the type specimen of R. multiplicata and most likely on Moure’s own recollection of the specimen. After examining photographs of the type specimen deposited in the NHMUK ( Figs.16-21 ), we concluded that the two females interpreted as Rhynostelis multiplicata by Moure and Urban (1995) actually correspond to two distinct species. Additionally, we recognize here a third new species of the genus from Panamá. The three species have similar color pattern and can be easily distinguished mainly by details of structure of the female mandible, clypeus and supraclypeal area.

The species of Rhynostelis can be recognized by the combination of a carinate frons; juxtantennal carina present; strong paraocular carina; pronotal lobe with short lamina; omaulus lamellate, almost extending ventrally; bigibbous scutum and scutellum; scutoscutellar suture broad and forming two foveae; fore and mid tibiae with one midapical spine on outer surface; hind tibia with flat apical projection on outer surface (more developed in females); arolia present; base of propodeum with irregular foveae. In addition, the females exhibit a tubercle or projection on the supraclypeal area; mandibles with raised condylar carina and a strong antero-basal projection.

Key to females of Rhynostelis (only the male of R. plesiognatha sp. nov. is known)

1. Mandible with bifurcated condylar carina; axillae rounded; scutellum with shallow posterior emargination ( Fig. 8 ); tergal pilosity brown to black ( Figs. 9 and 14 ); disc of T2 with larger and deeper punctures on its basal third ……………………………………………….2

1’. Mandible with simple condylar carina; axillae somewhat triangular; scutellum with strong posterior emargination ( Fig. 3 ); tergal pilosity yellowish ferruginous ( Fig. 4 ); disc of T2 with shallow punctures throughout.......................... Rhynostelis chrysogaster sp. nov.

2. Supraclypeal area not raised, except for the medial carina; clypeus with a small medial tubercle on its upper margin; mandible with a short truncate projection near anterior articulation ( Figs. 6 and 7 ) ..... ..................................................................... Rhynostelis plesiognatha sp. nov.

2’. Supraclypeal area and upper margin of clypeus with a large beak-shaped protuberance; mandible with a large horn-shaped projection near anterior articulation ( Figs. 11 and 12 )............................... ...................................................................................... Rhynostelis multiplicata

Figures

Figures 1-5. Rhynostelis chrysogaster sp. nov., holotype female. 1, head, frontal view; 2, head, posterodorsal view; 3, habitus, dorsal view; 4, metasoma, dorsal view; 5, habitus, lateral view. Scale line = 2.0 mm (Figs. 1, 2 and 4). Scale line = 5.0 mm (Figs.3, 5).

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).

Figures 16-21. Anthidium multiplicatum Smith, 1879, holotype female. 16, head, frontal view; 17, head, frontolateral view; 18, habitus, lateral view; 19, habitus, dorsal view; 20, detail of left wings; 21. Specimen labels.