A revised key to the Neotropical cleptoparasitic anthidiine genera (Hymenoptera, Megachilinae) with notes and description of the male of Rhynostelis Moure & Urban

Abstract

Rhynostelis Moure & Urban is a monotypic cleptoparasitic neotropical anthidiine genus currently known from two females. Herein, we describe and illustrate for the first time the male and its genitalia and it is confirmed that Rhynostelis parasitizes nests of Eufriesea. An identification key to the genera of cleptoparasitic anthidiine from the Neotropical region is also presented.

Revision of the rare anthidiine bee genus Rhynostelis Moure & Urban (Hymenoptera, Apidae)

“…Rhynostelis contains large and robust bees (13-16 mm of body length) with strong yellow markings on all tagmata, previously known from Amazonas, Brazil and French Guiana. Rhynostelis together with Hoplostelis are known to parasitize euglossine orchid bees: the latter parasitizes nests of Euglossa (Bennett, 1966;Augusto and Garófalo, 1998;Urban, 2003), while the former has been recorded from nests of Eufriesea (Moure and Urban, 1995;Parizotto and Urban, 2012). The females of Rhynostelis and Hoplostelis possess a mandibular projection that is probably used to open the resinous brood cells of their hosts, and not to kill the host eggs or larvae as suggested by Michener (2007).…”

“…Anthidiini is one the most diverse taxa of megachiline bees in the Neotropical region with approximately 350 described species (Urban and Moure, 2007). Among these Neotropical representatives, seven genera are known to behave as obligatory cleptoparasites, attacking not only other anthidiine bees but also nests of unrelated bee groups (summary in Parizotto and Urban, 2012). Two cleptoparasitic genera, Rhynostelis Moure and Urban and Melostelis Urban, are known to contain a single species each.…”

“…Two cleptoparasitic genera, Rhynostelis Moure and Urban and Melostelis Urban, are known to contain a single species each. These are very rarely collected bees and are currently known from six specimens, Melostelis only from the female holotype and Rhynostelis from four females, including the holotype, and a single male (Urban and Moure, 2007;Urban, 2011;Parizotto and Urban, 2012).…”

“…This has led us to reexamine the type material of Anthidium multiplicatum Smith, 1879, the type species of Rhynostelis, and to find out that the interpretation made by Moure and Urban (1995) was incorrect. This interpretation was followed by Parizotto and Urban (2012), who had mistaken the specimens they studied from Manaus and Belém, in Brazil, as belonging to R. multiplicata, instead of an undescribed new species. Here we recognize three species in Rhynostelis, two of them as new.…”