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United States Department of Agriculture

Agricultural Research Service

Research Project: Managing and Conserving Diverse Bee Pollinators for Sustainable Crop Production and Wildland Preservation

Location: Pollinating Insect-biology, Management, Systematics Research

Title: Taxonomic utility of environmental niche models for species distinction: A case study in Anthophora (Heliophila) (Hymenoptera: Apidae)

Author
item Orr, Michael
item Koch, Jonathan
item Griswold, Terry
item Pitts, James

Submitted to: Zootaxa
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2014
Publication Date: 8/4/2014
Citation: Orr, M.C., Koch, J.B., Griswold, T.L., Pitts, J.P. 2014. Taxonomic utility of environmental niche models for species distinction: A case study in Anthophora (Heliophila) (Hymenoptera: Apidae). Zootaxa. 3846:411-429.

Interpretive Summary: Taxonomy is the process by which species are recognized and correct names applied to them. This is important for all efforts in biology, because species are the units used for research even in such distantly related fields as behavior and ecology. One of the primary goals of taxonomy is to differentiate between similar species, since they may behave in different ways despite their similarities. For bees, this may involve the pollination of different plants, with implications for natural environments and agriculture. Differentiating species is most difficult in groups where body structures are very similar, such as is the case in the bee genus Anthophora. Two species originally recognized in this genus (Anthophora curta and Anthophora squammulosa) were collapsed into a single species by previous researchers because they are very similar in appearance. A combined analysis of distributions, climatic parameters, and body structures demonstrates that they are actually separate species. There is no geographical overlap between them and modelled predicted distributions based on bioclimatic data overlapped less than 1% of the time. An additional five similar species from within the distribution of Anthophora squammulosa were studied. All of them proved to be the same as Anthophora squammulosa and were synonymized with it.

Technical Abstract: Taxonomy has far-reaching effects throughout biology, and incorrect taxonomy can be detrimental in many ways. Polymorphic species complexes, many of which exist in the bee genus Anthophora Latreille, lend themselves to such difficulties. This study employs environmental niche mapping (ENM) and traditional morphological analyses to investigate the validity of the synonymy of Anthophora (Heliophila) curta with the senior synonym A. squammulosa. Eleven of fifty morphological characters consistently differentiate the two species, with an additional five characters sometimes separating them. Additionally, based on over 1000 georeferenced museum specimens, the geographic ranges of the two taxa do not overlap. The two entities also react differently to the bioclimatic variables based on correlation analysis. We further tested the two-species hypothesis by constructing ENMs with informative bioclimatic variables associated with locality records. Their modelled distributions overlapped less than 1%, suggesting discrete environmental boundaries. The variables which contributed most to each species’ model also differed. These differences are explored in relation to their habitats. The combined morphological and biogeographic analysis indicates that A. curta and A. squammulosa are distinct species. Based on the accumulated evidence the synonymy is formally rejected and A. curta is recognized as a valid species. Five additional taxa (A. bispinosa Cockerell, A. franciscana Cockerell, A. usticauda Cockerell, A. u. cinerior Cockerell, A. zamoranella Cockerell) are newly synonymized with A. squammulosa and Anthophora curta var. melanops Cockerell is newly synonymized with A. curta. Implications outside of taxonomy are discussed.

Last Modified: 10/18/2017
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