Bumble Bees (Hymenoptera: Apidae) of Texas: Historical Distributions

Abstract

Texas is the second largest state in the United States of America, and the largest state in the contiguous USA at nearly 700,000 sq. km. Several Texas bumble bee species have shown evidence of declines in portions of their continental ranges, and conservation initiatives targeting these species will be most effective if species distributions are well established. To date, statewide bumble bee distributions for Texas have been inferred primarily from specimen records housed in natural history collections. To improve upon these maps, and help inform conservation decisions, this research aimed to (1) update existing Texas bumble bee presence databases to include recent (2007-2016) data from citizen science repositories and targeted field studies, (2) model statewide species distributions of the most common bumble bee species in Texas using MaxEnt, and (3) identify conservation target areas for the state that are most likely to contain habitat suitable for multiple declining species. The resulting Texas bumble bee database is comprised of 3,580 records, to include previously compiled museum records dating from 1897, recent field survey data, and vetted records from citizen science repositories. These data yielded an updated state species list that includes 11 species, as well as species distribution models (SDMs) for the most common Texas bumble bee species, including two that have shown evidence of range-wide declines: B. fraternus (Smith, 1854) and B. pensylvanicus (DeGeer, 1773). Based on analyses of these models, we have identified conservation priority areas within the Texas Cross Timbers, Texas Blackland Prairies, and East Central Texas Plains ecoregions where suitable habitat for both B. fraternus and B. pensylvanicus are highly likely to co-occur. PeerJ reviewing PDF | (15 Abstract: 16 Texas is the second largest state in the United States of America, and the largest state in the 17 contiguous USA at nearly 700,000 sq. km. Several Texas bumble bee species have shown 18 evidence of declines in portions of their continental ranges, and conservation initiatives targeting 19 these species will be most effective if species distributions are well established. To date, 20 statewide bumble bee distributions for Texas have been inferred primarily from specimen 21 records housed in natural history collections. To improve upon these maps, and help inform 22 conservation decisions, this research aimed to (1) update existing Texas bumble bee presence 23 databases to include recent (2007-2016) data from citizen science repositories and targeted field 24 studies, (2) model statewide species distributions of the most common bumble bee species in 25 Texas using MaxEnt, and (3) identify conservation target areas for the state that are most likely 26 to contain habitat suitable for multiple declining species. The resulting Texas bumble bee 27 database is comprised of 3,580 records, to include previously compiled museum records dating 28 from 1897, recent field survey data, and vetted records from citizen science repositories. ...

An updated understanding of Texas bumble bee (Hymenoptera: Apidae) species presence and potential distributions in Texas, USA

“…The species presence records documented in this study included three new, albeit historically very rare, species from the list of Texas bumble bees previously published by Warriner (2012): B. appositus (n=1), B. morrisoni (n=5), and B. nevadensis (n=2). These records were retrieved from the database of museum records managed by Leif Richardson (Williams et al, 2014;L.…”

“…Previously compiled natural history collection records (Warriner, 2012;L. Richardson, unpublished dataset) Two citizen scientist repositories, iNaturalist and the Texas Bumblebees Facebook page (hereafter referred to as "Texas Bumblebees"), were also mined for presence records.…”

“…Historically, eight species of bumble bees have been documented in Texas (Franklin, 1913;Warriner, 2012): B. auricomus (Robertson, 1903), B. bimaculatus Cresson, 1863, B. fervidus (Fabricius, 1798), B. fraternus (Smith, 1854), B. griseocollis (DeGeer, 1773), B.…”

“…Additionally, B. pensylvanicus sonorus, sometimes classified as the distinct species B. sonorus Say, 1837 (Franklin, 1913;Stephen, 1957;Thorp et al, 1983;Warriner, 2012), has been documented in Texas. For the purposes of this research we have treated this taxon as a western morphological variant of B. pensylvanicus following Milliron (1973), Labougle (1990), Poole (1996), and Williams et al (2014), and refer to it hereafter as B. pensylvanicus sonorus.…”

“…An effective species conservation program requires delineation of the distribution of the species of interest (Eken et al, 2004), as well as an understanding of their habitat. Prior to the current study, efforts to establish Texas bumble bee distributions included the compilation and mapping of Texas specimen data from natural history collections by Warriner (2012) and targeted field studies in the northeastern portion of the state (Beckham et al, 2016). Williams et al (2014) also modeled range-wide species distributions for North American bumble bees, to include Texas species.…”