On the identity of the adventive species of Eufriesea Cockerell in the USA: systematics and potential distribution of the coerulescens species group (Hymenoptera: Apidae)

Authors: GONZALEZ, VICTOR - University Of Kansas; Griswold, Terry; SIMOES, MARIANNA - University Of Kansas

Submitted to: Journal of Hymenoptera Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2017
Publication Date: 4/28/2017
Citation: Gonzalez, V.H., Griswold, T.L., Simoes, M. 2017. On the identity of the adventive species of Eufriesea Cockerell in the USA: systematics and potential distribution of the coerulescens species group (Hymenoptera: Apidae). Journal of Hymenoptera Research. 55:55-102.

Interpretive Summary: Orchid bees are diverse group of brightly colored, largely tropical bees in several genera. They rarely have been found in the USA. One individual of the genus Eulaema was detected in southern Arizona, but no additional individuals have been seen. Another orchid bee species, this one in the genus Euglossa has successfully established in southern Florida. In 2010 two individuals of the genus Eufriesea were found in the Guadalupe Mountains of western Texas and southeastern New Mexico. It was unclear what species they belonged to and whether they were native to the US or accidental, perhaps brought in by a storm. Initially, it seemed likely that this was a new species, but study of similar looking Eufriesea from Mexico suggested it belong to Eufriesea coerulescens. Careful analysis of Mexican specimens indicated that Eufriesea coerulescens was actually a complex of six species. In this study we provide keys to diagnose the six species and describe the three that are new species. We confirm that the individuals from the US are Eufriesea coerulescens. Using climatic variables associated with all locations where Eufriesea coerulescens has been found we determine that the Guadalupe Mountains of the US are not suitable habitat and thus that Eufriesea coerulescens is unlikely to persist there.

Technical Abstract: In the summer of 2010, two male specimens of the neotropical orchid bee genus Eufriesea Cockerell were collected in the Guadalupe Mountains of western Texas and southeastern New Mexico, USA. We tentatively identified them as E. coerulescens (Lepeletier de Saint Fargeau) because of the uncertainty surrounding the limits of this taxon and hypothesized that they were members of a persistent bee population, rather than long-distance transient vagrants. The goals of this paper are to clarify the identity of these specimens, assess the species limits of E. coerulescens, and to evaluate the probability of suitable habitats in the USA for this adventive species. Herein, we revise the species in the coerulescens group using morphological features of both sexes and confirm that the specimens of Eufriesea from the USA are E. coerulescens. We recognize the following six species in the coerulescens group: E. coerulescens, E. micheneri Ayala & Engel, E. simillima (Moure & Michener), which is reinstated from synonym with E. coerulescens, and three new species from Mexico (E. barthelli Gonzalez & Griswold, sp. nov., E. engeli Gonzalez & Griswold, sp. nov., and E. oliveri Gonzalez & Griswold, sp. nov.). To facilitate the identification of these taxa, we present a fully illustrated account of the species, comparative diagnoses, descriptions, and an updated key to all Mexican species of Eufriesea. Our analyses using species distribution modelling show an absence of suitable habitat for E. coerulescens in western Texas and southeastern New Mexico, thus favoring the long-distance dispersal hypothesis. The analyses also suggest high probability of suitable habitat across the Caribbean and some areas in Florida, as well as in other regions in Mexico and Central America. We discuss the implications of these results and compare them with the predicted distribution available for the other two known adventive orchid bee species in the USA