Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the Neotropics Anthony Raw Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brasil. 45650-000 [email protected] Last revised: 20 November 2004 Anthony Raw, 2004. Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the 1 Neotropics. www.webbee.org.br ABSTRACT Megachile is treated here as a single genus combining Megachile with Chalicodoma. In the Americas the genus occurs from Alaska and the mid latitudes of Canada to southern Chile and Argentina, but most species are tropical. They are important pollinators of many crops and other useful plants. Despite their economic and ecological importance, the biology of few species has been studied in detail because they are difficult to identify. The 395 species in the catalogue are allocated to 26 subgenera (including 9 Old World species introduced to the region during historical times). Summaries of information on each species‘ classification, biology and geographical distributions are given. Anthony Raw, 2004. Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the 2 Neotropics. www.webbee.org.br CONTENTS Preface Erro! Indicador não definido. Introduction 5 Taxonomic review 5 Geographical distribution 7 Biology 9 Flower relationships 11 Identification 12 Presentation of data 13 Genus Megachile Latreille 15 Subgenus Acentron Mitchell 15 Subgenus Argyropile Mitchell 18 Subgenus Austromegachile Mitchell 19 Subgenus Callomegachile Michener 25 Subgenus Chelostomoides Robertson 26 Subgenus Chrysosarus Mitchell 29 Subgenus Cressoniella Mitchell 37 Subgenus Dasymegachile Mitchell 39 Subgenus Eutricharaea Thomson 41 Subgenus Gronoceras Cockerell 44 Subgenus Leptorachis Mitchell 44 Subgenus Litomegachile Mitchell 50 Subgenus Melanosarus Mitchell 51 Subgenus Moureapis Raw 53 Subgenus Neochelynia Schrottky 57 Subgenus Pseudocentron Mitchell 60 Subgenus Pseudomegachile Friese 71 Subgenus Ptilosaroides Mitchell 73 Subgenus Ptilosarus Mitchell 73 Subgenus Rhyssomegachile Mitchell 75 Subgenus Sayapis Titus 76 Subgenus Schrottkyapis Mitchell 80 Subgenus Stelodides Moure 81 Subgenus Trichurochile Mitchell 81 Subgenus Tylomegachile Mitchell 82 Subgenus Zonomegachile Mitchell 83 Fossil species 84 New World bees placed erroneously in Megachile 84 Nomina nuda 84 Appendix: Collection abbreviations 85 References 86 Anthony Raw, 2004. Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the 3 Neotropics. www.webbee.org.br Preface This inventory is a labour of Sisyphus; it has no end. I have been compiling it for years. With 307 references and thousands of citations in the text it is a formidable task. Additional references are continually coming to light. Despite the unfinished state of the work, I have been persuaded that people will find it useful in its present state. In making it available I ask the reader to inform me of errors and omissions, which I shall be happy to include in the inevitable revisions. A major part of this investigation was made possible with an award from the Royal Society of London, which allowed me to spend a sabbatical at the University of Oxford. Visits to the British Museum (Natural History) were made possible with grants from the British Council and the Conselho Nacional de Pesquisas [CNPq [Brazilian National Research Council]. CNPq also my financed visits to the Universidade Federal do Paraná in Curitiba, and the Museu Nacional and Instituto Osvaldo Cruz, both in Rio de Janeiro. The Smithsonian Institution provided a research grant to visit the National Collection in Washington and also the collections in the American Museum of Natural History, New York and the Academy of Natural Sciences in Philadelphia. I am sincerely grateful to these Institutions for their support. I have received on loan more than 4,000 specimens of neotropical Megachile. The following entomologists have provided me with specimens which have been invaluable for this work. I thank Mr. M. C. Day and Mr. G. R. Else, British Museum (Natural History), London; Mr. C. O'Toole, University Museum, Oxford, England; Dr. R. M. McGinley, Smithsonian Institution; Dr. J. R. Rozen of the American Museum of Natural History, New York; Dr. R. B. Roberts, Rutgers University; Dr. C. D. Michener, University of Kansas; Dr. G. E. Bohart and Dr. Terry L. Griswold, Bee Biology and Systematics Laboratory, U.S.D.A., Logan, Utah, U.S.A.; the late Dr. G. C. Eickwort, University of Cornell; Dr. W. E. LaBerge, Illinois Natural History Survey; Dr. G. Alayon García, Cuba; Dr. D. Roubik, Smithsonian Tropical Research Institute, Panamá; Dr. Edgar Ormachea Acurio, Universidade Nacional San Antonio Abad del Cusco, Peru; F. Fernández, Universidad Nacional de Colombia, Bogotá; Sr. J.A. Rafael, Instituto Nacional de Pesquisas da Amazônia, Manaus and Dr. W. L. Overal, Museu Paraense Emilio Goeldi, Belém and Padre Jesus Santiago Moure of the Universidade Federal do Paraná, Curitiba. Dr. Claire Villemont of the Musée National de Histoire Naturelle, Paris kindly delivered by hand many of the types of Vachal. Mr. Christopher O'Toole of the Oxford University Museum and Dr. V. O. Becker of Brasilia have been of great assistance during this study. Since the catalogue has been made accessible on the www various colleagues have provided additional information. I thank Dr. Julio Gerano of Cuba and Dr. Steven Buchmann of TheBeeWorks, Arizona for their comments. Mr. Claus Rasmussen, Department of Entomology, University of Illinois has provided important information on Peruvian localities. Anthony Raw, 2004. Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the 4 Neotropics. www.webbee.org.br Introduction Members of the genus Megachile are among the best known bees (O‘Toole & Raw 1991). Here I have followed Michener et al (1994, 2000) and treated the group as a single genus combining Megachile with Chalicodoma. Most are called "leaf-cutter bees" because the females cut leaves and petals to line their nests. Others are the "mason bees" because they construct their nests with resin, mud or leaves chewed into pulp. The neotropical species are from half to three times the length of a honeybee. The aim of this inventory is to disentangle some of the great confusion that exists over the identification of the species of Megachile of the Neotropics. Identification to subgenus and knowledge of the geographical distributions of the members of the subgenus substantially reduces the number of options and assists identification to species or species group. I hope easier identification will stimulate studies on the bees‘ biology and enable researchers to better assess their roles as pollinators. For each species the subgenus is indicated, the valid name and changes of names are listed and information on the bee‘s biology and its geographical distribution are given. The subgenera are indicated to which 395 neotropical species belong, including 9 Old World species introduced to the region during historical times. Dalla Torre (1896) listed 92 neotropical species now included in the genus Megachile. Three neotropical species were erroneously placed at some time in the genus Megachile. Their present statuses are indicated below. There are also five nomina nudae. Nomenclatural questions of subgenus or species groups and of subspecies are not discussed. Species of Megachile can be placed with certainty in their correct subgenera only by examining the type specimens. Nonetheless, a number of authors have done so without stating the situation. In order to improve the authority of this work, to date I have examined 246 type specimens of neotropical Megachile. In all the cases where —Examined“ is stated I have seen the holotype. In those cases where I have not done so, the basis of my decision is clearly stated. Taxonomic review The genus Megachile was created by Latreille in 1802 and, as originally conceived, it was equivalent to the present family Megachilidae which comprises one of the largest groups of bees. Of the species which Latreille included in Megachile today only the European species, M. centuncularis and M. lagopoda remain. Very soon, various authors began to divide up Latreille‘s genus into new genera. The first were Anthidium by Fabricius (1804), Osmia and Stelis by Panzer (1806), Heriades by Spinola (1808) and Latreille, himself, proposed Coelioxys in 1809. Westwood (1840) designated the European species Apis centuncularis Linnaeus as the type of the genus Megachile. Lepeletier (1841) erected the genus Chalicodoma for the species whose body shape and mandibles differed from typical Megachile, but Mitchell (1934) returned it to the latter genus. Creightonella was created as a subgenus of Chalicodoma by Cockerell (1908a). Michener (1962) re-examined the Anthony Raw, 2004. Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the 5 Neotropics. www.webbee.org.br Table 1. The extant species of Megachile of the Americas arranged by subgenus Subgenus Restricted to Both Restricted Total Total neotropics realms to nearctic Americas neotropical Acentron 21 1 22 22 Argyropile 2 6 8 2 Austromegachile 37 37 37 Callomegachile 4 4 4 Chelostomoides 16 1 17 34 17 Chrysosarus 51 51 51 Cressoniella 19 1 20 20 Dasymegachile 13 13 13 Eutricharaea 2 1 2 5 3 Gronoceras 1 1 1 Grosapis 1 1 0 Leptorachis 38 38 38 Litomegachile 1 5 6 1 Megachile 5 5 0 Megachiloides 59 59 0 Melanosarus 10 1 11 10 Moureapis 30 30 30 Neochelynia 17 17 17 Pseudocentron 68 2 3 73 70 Pseudomegachile 1 1 1 Ptilosaroides 2 2 2 Ptilosarus 15 15 15 Rhyssomegachile 3 3 3 Sayapis 21 3 6 30 24 Schrottkyapis 1 1 1 Stelodides 1 1 1 Trichurochile 3 3 3 Tylomegachile 6 6 6 Xanthosarus 15 15 0 Zonomegachile 3 3 3 Total 384 11 120 515 395 Percentage 74,6 2,1 23,3 Anthony Raw, 2004. Leafcutter and Mason Bees: a Biological Catalogue of the Genus Megachile of the 6 Neotropics. www.webbee.org.br groups and recognized the genus Megachile as "leaf-cutter bees" and Chalicodoma as "mason bees".