Abstract

A new species of Megachile Latreille, subgenus Pseudocentron Mitchell (Hymenoptera: Apoidea: Megachilidae) is described, exhibiting marked sexual dimorphism: Megachile karlquesteli new species. Only about five species of Megachile whose females have a dark black integument and predominantly black pubescence occur in the Antilles. A distinctive combination of morphological characters separates this species from other taxa. Female is characterized by a dark black tegument and pubescence, while the male possesses a dark brown tegument, darker on the metasoma, except for the tarsi and most of the foreleg, which are reddish-brown; yellow pubescence covers the frons, mesosoma, T1, and T2. The most pronounced differences, however, occur in the males, in which the structure of the apical sterna, particularly sterna 5, 6, and 8, provides reliable diagnostic features. The new species inhabits the Anguilla Bank in the Caribbean Sea. The bee was observed visiting a variety of flowers: Acanthaceae: Asystasia gangetica (L.) T. Anderson; Asteraceae: Borrichia arborescens (L.) DC., Tridax procumbens L.; Aizoaceae: Trianthema portulacastrum L.; Euphorbiaceae: Euphorbia milii Des Moul.; Goodeniaceae: Scaevola plumieri (L.) Vahl; Malvaceae: Waltheria indica L., Corchorus hirsutus L., Melochia tomentosa L.; Polygonaceae: Antigonon leptopus Hook. & Arn.; Zygophyllaceae: Guaiacum officinale L.

Resumen

Se describe una especie nueva de Megachile Latreille, subgénero Pseudocentron Mitchell (Hymenoptera: Apoidea: Megachilidae), que presenta un marcado dimorfismo sexual: Megachile karlquesteli nueva especie. Solamente unas cinco especies de Megachile cuyas hembras poseen el tegumento negro oscuro y pubescencia predominantemente negra habitan en las Antillas. Una combinación de caracteres morfológicos la separa de otras especies. La hembra se caracteriza por un tegumento y pubescencia de color negro oscuro, mientras que el macho tiene el tegumento de color castaño oscuro, más oscuro en el metasoma, excepto en los tarsos y la mayor parte de la pata anterior, que son de color castaño rojizo; una pubescencia amarilla cubre el frente de la cabeza, mesosoma, T1 y T2. Las mayores diferencias se encuentran en los machos, entre los cuales la terminalia y principalmente los esternos 5,6 y 8 son muy útiles. La nueva especie habita el Banco de Anguila, en el Mar Caribe. Se observó a la abeja visitando una variedad de flores: Acanthaceae: Asystasia gangetica (L.) T. Anderson; Asteraceae: Borrichia arborescens (L.) DC., Tridax procumbens L.; Aizoaceae: Trianthema portulacastrum L.; Euphorbiaceae: Euphorbia milii Des Moul.; Goodeniaceae: Scaevola plumieri (L.) Vahl; Malvaceae: Waltheria indica L., Corchorus hirsutus L., Melochia tomentosa L.; Polygonaceae: Antigonon leptopus Hook. & Arn.; Zygophyllaceae: Guaiacum officinale L.

References

• Christman RA. 1953. Geology of St. Bartholomew, St. Martin, and Anguilla, Lesser Antilles. Bulletin of the Geological Society of America 64: 85–96. https://doi.org/10.1130/0016-7606(1953)64[85:GOSBSM]2.0.CO;2 
• Coelho IR. 2016. Filogenia e classifcação de Megachile Latreille, 1802 grupo Pseudocentron, sensu Mitchell, 1980. Universidade Federal de Minas Gerais, Brazil. 260 p 
• de Massary J-C, Bochaton C, Bour R, Dewynter M, Ineich I, Vidal N, Lescure J. 2018. Liste taxinomique de l’herpétofaune dans l’outre-mer français. II. Collectivité de Saint-Barthélemy. Bulletin de la Société Herpétologique de France 166: 59–78.  
• Freytes-Rivera A, Kardas E, Genaro JA, Fumero-Cabán JJ, Rojas-Sandoval J. 2025. First record of Megachile (Pseudocentron) luctifera (Hymenoptera: Megachilidae) in Puerto Rico. Caribbean Naturalist 102: 1–7.  
• Genaro JA. 1998. Distribution and synonymy of some Caribbean bees of the genera Megachile and Coelioxys (Hymenoptera: Megachilidae). Caribbean Journal of Science 34: 151–152.  
• Genaro JA. 2002. Megachile (Pseudocentron) jerryrozeni, a new species of leafcutting bee (Hymenoptera: Megachilidae) from the Cayman Islands. Journal of the Kansas Entomological Society 76: 286–289.  
• Genaro JA. 2007. Las abejas (Hymenoptera: Apoidea: Anthophila) de la Hispaniola, Antillas. Boletín de la Sociedad Entomológica Aragonesa, Spain 40: 247.  
• González VH. 2008. Phylogeny and classifcation of the bee tribe Megachilini (Hymenoptera: Apoidea, Megachilidae), with emphasis on the genus Megachile. Doctoral dissertation, University of Kansas; Lawrence, KS. 274 p 
• González VH, Gustafson GT, Engel MS. 2019. Morphological phylogeny of Megachilini and the evolution of leaf-cutter behavior in bees (Hymenoptera: Megachilidae). Journal of Melittology 85: 1–123. https://doi.org/10.17161/jom.v0i85.11541 
• Guérin-Méneville FE. 1844. Iconographie du règne animal de G. Cuvier, ou représentation d’après nature de l’une des espèces les plus remarquables, et souvent non encore fgurées, de chaque genre d’animaux; pouvant servir d’atlas à tous les traités de Zoologie. Paris: Baillière, J.B. 7: 1–576.  
• Guiglia D, Pasteels J. 1961. Aggiunte ed osservazioni all’elenco delle specie di imenotteri descritte da Guérin-Méneville che si trovano nelle collezioni del Museo di Genova. Annali del Museo Civico di Storia Naturale Giacomo Doria 72: 17–20.  
• Harris RA. 1979. A glossary of surface sculpturing. Occasional Papers in Entomology, Department of Food and Agriculture, Division of Plant Industry, California 28: 1–31.  
• Hebert PDN, Cywinska A, Ball SL, deWaard JR. 2003. Biological identifcations through DNA barcodes. Proceedings of the Royal Society of London, Series B, Biological Sciences 270: 313–321. https://doi.org/10.1098/rspb.2002.2218 
• Kimura M. 1980. A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences. Journal of Molecular Evolution 16: 111–120. https://doi.org/10.1007/BF01731581 
• BF01731581 Meurgey F. 2016. Bee species and their associated fowers in the French West Indies (Guadeloupe, Les Saintes, La Désirade, Marie Galante, St Barthelemy and Martinique) (Hymenoptera: Anthophila: Apoidea). Annales de la Société Entomologique de France (N.S.) 52: 209–232. https://doi.org/10.1080/00379271.2016.1244490 
• Meurgey F, Questel K. 2015. Liste préliminaire des Abeilles de Saint-Barthélemy (Antilles françaises) et leurs relations avec la fore butinée (Hymenoptera: Apoidea: Megachilidae, Apidae). Annales de la Société Entomologique de France (N.S.) 51: 208–214. https://doi.org/10.1080/00379271.2015.1061232 
• Michener CD. 2007. Te bees of the world. 2nd Edition. Johns Hopkins University Press; Baltimore, MD. 992 p 
• Mitchell TB. 1937. A revision of the genus Megachile in the Nearctic Region. Part VI. Taxonomy of Subgenera Argyropile, Leptorachis. Pseudocentron, Acentron and Melanosarus (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 63: 45–83.  
• Mitchell TB. 1980. A generic revision of the megachiline bees of the Western Hemisphere. North Carolina State University; Raleigh, NC. 95 p 
• Moure JS, Melo GAR. 2022. Megachilini Latreille, 1802. In: Moure JS, Urban D, Melo GAR (orgs.). Catalogue of bees (Hymenoptera, Apoidea) in the Neotropical Region - online version. Available at https://moure.cria.org.br/catalogue  (Last accessed September 7, 2025.)
• Questel K. 2022. Assessment of Anguilla’s pollinator insects and associated plants (November 2021). Anguilla National Trust; Anguilla. 75 p 
• Questel K, Hochart J. 2018. Annotated list of fora and fauna on the Prickly Pear Cays, Anguilla, BWI. Agence Territoriale de l’Environnement de Saint-Barthélemy; Anguilla. . 44 p 
• Ratnasingham S, Hebert PDN. 2007. BOLD: Te Barcode of Life Data System (www.barcodinglife.org). Molecular Ecology Notes 7(3): 355–364. https://doi.org/10.1111/j.1471-8286.2007.01678.x 
• Ratnasingham S, Wei C, Chan D, Agda J, Agda J, Ballesteros-Mejia L, Ait Boutou H, El Bastami ZM, Ma E, Manjunath R, Rea D, Ho C, Telfer A, McKeowan J, Rahulan M, Steinke C, Dorsheimer J, Milton M, Hebert PDN. 2024. Chapter 26. BOLD v4: A centralized bioinformatics platform for DNA-based biodiversity data. p. 403–441. In: DeSalle R (ed.). DNA barcoding: Methods and protocols. Springer; New York, NY. 576 phttps://doi.org/10.1007/978-1-0716-35810_26 
• Raw A. 2007. An annotated catalogue of the leafcutter and mason bees (genus Megachile) of the Neotropics. Zootaxa 1601: 1–127. https://doi.org/10.11646/zootaxa.1601.1.1 
• Shefeld CS, Ratti C, Packer L, Griswold T. 2011. Leafcutter and mason bees of the genus Megachile Latreille (Hymenoptera: Megachilidae) in Canada and Alaska. Canadian Journal of Arthropod Identifcation 18: 1–107. https://doi.org/10.3752/cjai.2011.18 
• Silvana PD, Torretta JP. 2010. First description of male of Megachile (Pseudocentron) gomphrenoides Vachal and redescription of female (Hymenoptera, Megachilidae). Transactions of the American Entomological Society 136(3/4): 235–240. https://doi.org/10.3157/061.136.0304 
• Trunz V, Packer L, Vieu J, Arrigo N, Praz CJ. 2016. Comprehensive phylogeny, biogeography and new classifcation of the diverse bee tribe Megachilini: Can we use DNA barcodes in phylogenies of large genera? Molecular Phylogenetics and Evolution 103: 245–259. https://doi.org/10.1016/j.ympev.2016.07.004