title: The influence of habitat heterogeneity and latitude on gamma diversity of the Nearctic Simuliidae, a ubiquitous group of stream-dwelling insects.
abstract: Among the most prominent, large-scale patterns of species richness are the increases in richness with decreasing latitude and with increasing habitat heterogeneity. Using the stream-dwelling larval and pupal stages of North American black flies (Diptera: Simuliidae), we address 3 broad questions about species richness: (i) Does a significant latitude-richness relationship exist? (ii) How does habitat heterogeneity influence gamma diversity? (iii) What is the sign (positive or negative) of the latitude-richness and the heterogeneity-richness relationships? We found no evidence that habitat heterogeneity influences gamma diversity. The estimated peak species richness for black flies in North America was at 50-53°N, which also corresponds with peak generic richness. All plesiomorphic, extant lineages of the Simuliidae in the Western Hemisphere are found in cool mountainous environments of North America, suggesting that peak richness at 50-53°N might be a signature of this phylogenetic pattern and a reflection of underlying historical processes.
authors.affiliation: Department of Biology, University of South Alabama, Mobile, Alabama, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: McCreadie
authors.affiliation: Department of Biology, University of South Alabama, Mobile, Alabama, USA.
authors.forename: Rachel H
authors.initials: RH
authors.lastname: Williams
authors.affiliation: Department of Earth Sciences Biology, University of South Alabama, Mobile, Alabama, USA.
authors.forename: Sam
authors.initials: S
authors.lastname: Stutsman
authors.affiliation: Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA.
authors.forename: Debra S
authors.initials: DS
authors.lastname: Finn
authors.affiliation: Department of Plant and Environmental Sciences, Clemson University, Clemson, South Carolina, USA.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Adler
mesh_terms: D000818:Animals; D044822:Biodiversity; D017753:Ecosystem; D005843:Geography; D007814:Larva; D009656:North America; D010802:Phylogeny; D011157:Population Dynamics; D011679:Pupa; D045483:Rivers; D012843:Simuliidae / Q000145:classification* / Q000254:growth & development
keywords: North America; Simuliidae; aquatic insects; biodiversity; gamma richness; streams