identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
4A7B7945FFA7EB5E9ACC34CD0F74F8E8.text	4A7B7945FFA7EB5E9ACC34CD0F74F8E8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Bombias) auricomus (Robertson 1903)	<div><p>Bombus (Bombias) auricomus (Robertson)</p> <p>‘Black &amp; Gold Bumble Bee’</p> <p>Bombus auricomus was not listed as occurring in Arkansas in Franklin’s (1912) account of the bumble bees of the New World, but was recognized as B. nevadensis auricomus in seven counties in Chandler &amp; McCoy’s (1965) statewide account (Fig. 1). Bombus auricomus and its close relative in the west, B. (B.) nevadensis Cresson, are currently thought of as separate species (Cameron et al., 2007; Scholl et al., 1992). Bombus auricomus is the longest-glossa bumble bee in the state, but it is an early-season species compared to others in the area. It has a relatively short active period and is among the rarer species in the state (7% of specimens of Bombus in the UAAM collection). In northwest Arkansas, B. auricomus is one of the earliest species to establish colonies, and these colonies are typically completed by early July. In other areas of its range, B. auricomus seems to follow a different seasonal schedule. The species is a late-season species relative to other species in Ontario (Colla &amp; Dumesh, 2010) and a mid-season species in Alberta (Hobbs, 1965). In Virginia, males were still actively seeking mates in mid-August (Alcock &amp; Alcock, 1983), suggesting that colonies in Virginia persist much later than they do in Arkansas. The distribution of B. auricomus in North America seems to be primarily north of Arkansas. Indeed, the southern half of Arkansas is not included in recent range maps of the species (Colla et al., 2011; Williams et al., 2014), although historic records of its occurrence are known (Fig. 1). Although uncommon throughout the state, the occurrence of B. auricomus has increased between the historic (18%) and contemporary periods (31%, Fig. 3).</p> <p>Bombus auricomus has garnered some conservation attention of late. Throughout North America, B. auricomus persists in less than 50% of its historic range, but its relative abundance appears unchanged (Colla et al., 2012). In Arkansas, the presence of B. auricomus in the extreme southwestern region of the state was not confirmed in recent surveys of the Blackland Prairie remnants, prompting some concern for its status in the region (Warriner, 2011). In the central portion of its range in Illinois, contemporary surveys show that B. auricomus is as widely distributed and abundant today as in the past (Grixti et al., 2009). As with species like B. fraternus and B. variabilis, the relative rarity of B. auricomus in some areas of its distribution renders collection records inconsistent and creates a challenge for comparative studies seeking to establish the conservation status of this species.</p> <p>GLOSSA LENGTH: Long (7.12 ± 0.39 mm).</p> <p>ADULT ACTIVE PERIOD: Early season with a short active period (58 days). Majority: mid-May through early July; Earliest: April 18; Latest: August 11.</p> <p>PREFERRED PLANTS: Monarda fistulosa (wild bergamot, Lamiaceae), Baptisia alba (white wild indigo, Fabaceae), B. bracteata (longbract wild indigo, Fabaceae), Penstemon digitalis Nutt. ex. Sims. (foxglove beardtongue, Plantaginaceae), Pycnanthemum tenuifolium Schrad. (narrowleaf mountainmint, Lamiaceae).</p> </div>	https://treatment.plazi.org/id/4A7B7945FFA7EB5E9ACC34CD0F74F8E8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA6EB5F9AC535ED0DA3FDC8.text	4A7B7945FFA6EB5F9AC535ED0DA3FDC8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Pyrobombus) bimaculatus Cresson	<div><p>Bombus (Pyrobombus) bimaculatus Cresson</p> <p>‘Two-spotted Bumble Bee’</p> <p>Bombus bimaculatus is, along with B. auricomus, one of the earliest species to become active in Arkansas. It also has the shortest active period in northwest Arkansas, with the majority of individuals spotted over a period of only 48 days. Although Chandler &amp; McCoy (1965) stated that they observed this species in the state during late summer and early fall, only three of 214 specimens of B. bimaculatus in the UAAM collection were collected after July. These were collected in 1964 and 1976, and all were from Washington County. In spite of its short active period, the proportion of counties with records of B. bimaculatus increased dramatically from 13% of sampled counties in the historic period to 44% in the contemporary period (Fig. 3). Bombus bimaculatus showed a strong preference for non-native vetch species, with 64% of all specimens observed on V. sativa and V. villosa. Vetches have been naturalized through much of the southeastern North America and are often grown as forage and cover crops, and for erosion control (Owsley, 2011). Perhaps their ability to use novel plant resources has contributed to the increased presence of B. bimaculatus in Arkansas, although other studies have also reported recent increases in B. bimaculatus throughout its range (Cameron et al., 2011; Colla &amp; Packer, 2008; Colla et al., 2012).</p> <p>GLOSSA LENGTH: Medium (5.65 ± 0.64 mm).</p> <p>ADULT ACTIVE PERIOD: Early season with a short active period (48 days). Majority: mid-May through late June; Earliest: April 22; Latest: August 1.</p> <p>PREFERRED PLANTS: Vicia villosa (winter vetch, Fabaceae), V. sativa (garden vetch, Fabaceae), P. digitalis (foxglove beardtongue, Plantaginaceae), T. canadense (Canada germander, Lamiaceae).</p> </div>	https://treatment.plazi.org/id/4A7B7945FFA6EB5F9AC535ED0DA3FDC8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA6EB5C9AF8312D0E31FD48.text	4A7B7945FFA6EB5C9AF8312D0E31FD48.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Thoracobombus) fervidus (Fabricius 1798)	<div><p>Bombus (Thoracobombus) fervidus (Fabricius)</p> <p>‘Yellow Bumble Bee’</p> <p>Franklin (1912) reported B. fervidus as absent throughout “the greater part of Arkansas ”, but, lacking deposited specimens, its presence could not be confirmed by Chandler &amp; McCoy (1965). Although B. fervidus has intermittently been reported in the state (Franklin, 1912; Warriner, 2011), and niche modeling suggests that the northwestern portion of the state could be marginally suitable for the species (Williams et al., 2014), its presence here is dubious. A recent survey of Bombus in remnant grasslands throughout the state reported B. fervidus in Boone and Franklin Counties in 2003 (Warriner, 2011), the first such sightings since it was reported 90 years prior (Franklin, 1912). The Boone County specimen was the only state record of this species with a deposited voucher specimen. Another historical specimen identified as B. fervidus is among the specimens in the UAAM collection: a male collected October 1, 1963 in Columbia County in the southern extreme of the state. These two specimens deposited in the UAAM collection as B. fervidus were both males, yet investigations of genitalic characters by the authors revealed that they are actually B. pensylvanicus.</p> <p>Males of B. fervidus superficially resemble some of the variants of male B. pensylvanicus, and the two species can be difficult to distinguish (Mitchell, 1962). Although Mitchell (1962) suggests a number of external characters that can be helpful, B. pensylvanicus and B. fervidus males can only be reliably distinguished by comparing their genitalia. The most obvious difference is in the penis valves (sensu Michener, 2007; Mitchell, 1962). The enlarged apices of the penis valves of B. pensylvanicus are long and slender, while the apices of those of B. fervidus are more truncate, with the breadth and width about equal. Additionally, the interior process of the gonostylus of B. pensylvanicus is flattened and broad, unlike that of B. fervidus. Bombus fervidus was not observed in 2011–2013 standardized surveys that we conducted throughout the northwestern portion of Arkansas, despite intensive sampling each season (number of observations = 1693). The North American distribution of B. fervidus appears to be primarily western and northeastern (Koch et al., 2012; Williams et al., 2014). To date, there are no deposited specimens of B. fervidus collected in Arkansas. Although we cannot discount its occasional presence in Arkansas, it seems more likely that records of this species in Arkansas are based on misidentifications of males, rather than true occurrences. The Arkansas Natural Heritage Commission lists B. fervidus as a species of concern within the state, with a ranking of S1, an “extremely rare” species at risk of statewide extirpation, known from Boone and Franklin Counties (ARNC, 2014). Investing in the conservation of species that are not true residents of an area, such as vagrants or marginal species (i.e., ones that occasionally occur in an area at the extreme of the species’ range margin) is an inefficient approach to conservation that squanders scarce resources (Rodrigues &amp; Gaston, 2002). Because there are no vouchered specimens of this species collected in Arkansas, we recommend that this state ranking be re-assessed.</p> <p>GLOSSA LENGTH: Long (6.50 ± 0.74 mm).</p> <p>ADULT ACTIVE PERIOD: Not in the state.</p> <p>PREFERRED PLANTS: Unknown.</p></div> 	https://treatment.plazi.org/id/4A7B7945FFA6EB5C9AF8312D0E31FD48	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA5EB5C9AF436AD0E02F8CB.text	4A7B7945FFA5EB5C9AF436AD0E02F8CB.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Cullumanobombus) fraternus (Smith 1854)	<div><p>Bombus (Cullumanobombus) fraternus (Smith)</p> <p>‘Southern Plains Bumble Bee’</p> <p>In their museum survey, Chandler &amp; McCoy (1965) noted B. fraternus as “widespread”, and it was recorded in as many counties as B. griseocollis (Fig. 3). Bombus fraternus remains widely distributed across Arkansas, and its occurrence has remained stable between the historic (36%) and contemporary periods (33%, Fig. 3). Although B. fraternus appears to have a wide geographic distribution, it is relatively less abundant than its congeners (Colla et al., 2012; Grixti et al., 2009). There are some indications that B. fraternus may be declining and the International Union for Conservation of Nature has classified the species as endangered (Hatfield et al., 2014), but its relative rarity makes it difficult to be certain of its status. Throughout its range, B. fraternus has declined in relative abundance and in geographic persistence, but its relative abundance over all museum records was only 0.32% (Colla et al., 2012). Similarly, an Illinois study designated B. fraternus as declining after finding that it was absent from the southern region of the state where it was formerly present, but its relative abundance ranged from 0.2–1.9% over all studied records spanning 1900 to 2007 (Grixti et al., 2009).</p> <p>GLOSSA LENGTH: Short (4.69 ± 0.37 mm).</p> <p>ADULT ACTIVE PERIOD: Late season with a long active period (92 days). Majority: early July through early October; Earliest: April 6; Latest: October 3.</p> <p>PREFERRED PLANTS: Passiflora incarnata Linnaeus (purple passionflower, Passifloraceae), S. integrifolium (wholeleaf rosinweed, Asteraceae), Solidago Linnaeus (goldenrod, Asteraceae), Liatris pycnostachya Michx. (prairie blazing star, Asteraceae), Silphium Linnaeus (rosinweed, Asteraceae), Bidens aristosa (Michx.) Britt. (bearded beggarticks, Asteraceae), Cephalanthus occidentalis Linnaeus (common buttonbush, Rubiaceae), Solidago altissima Linnaeus (Canada goldenrod, Asteraceae), Verbesina virginica Linnaeus (white crownbeard, Asteraceae).</p> </div>	https://treatment.plazi.org/id/4A7B7945FFA5EB5C9AF436AD0E02F8CB	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA4EB5D9A1D35ED085FFD0B.text	4A7B7945FFA4EB5D9A1D35ED085FFD0B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Cullumanobombus) griseocollis (De Geer 1773)	<div><p>Bombus (Cullumanobombus) griseocollis (De Geer)</p> <p>‘Brown-belted Bumble Bee’</p> <p>Bombus griseocollis is a widely distributed species in both eastern and western North America (Koch et al., 2012; Williams et al., 2014). Within Arkansas, the occurrence of B. griseocollis has greatly increased between the historic (36%) and contemporary periods (56%, Fig. 3). Two specimens in UAAM were captured in the period between the sampling periods in this study: Johnson Co., July, 1978 and Cleburne Co., April 19, 1969.</p> <p>GLOSSA LENGTH: Short (4.91 ± 0.50 mm).</p> <p>ADULT ACTIVE PERIOD: Early season with a short active period (60 days). Majority: early June through early August; Earliest: April 18; Latest: October 15.</p> <p>PREFERRED PLANTS: Cephalanthus occidentalis (common buttonbush, Rubiaceae), P. tenuifolium (narrowleaf mountainmint, Lamiaceae), T. canadense (Canada german- der, Lamiaceae), L. pycnostachya (prairie blazing star, Asteraceae), C. nutans (nodding plumeless thistle, Asteraceae), Asclepias hirtella (Pennell) Woodson (green milkweed, Apocynaceae), A. viridis Walter (green antelopehorn, Apocynaceae), V. villosa (winter vetch, Fabaceae), Centaurea stoebe Lam. (spotted knapweed, Asteraceae), M. fistulosa (wild bergamot, Lamiaceae), S. integrifolium (wholeleaf rosinweed, Asteraceae).</p> </div>	https://treatment.plazi.org/id/4A7B7945FFA4EB5D9A1D35ED085FFD0B	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA4EB5A9AD0366D0F51FFC8.text	4A7B7945FFA4EB5A9AD0366D0F51FFC8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Pyrobombus) impatiens Cresson	<div><p>Bombus (Pyrobombus) impatiens Cresson</p> <p>‘Common Eastern Bumble Bee’</p> <p>The occurrence of B. impatiens has more than tripled between the historic (21%) and contemporary sample periods (72%, Fig. 3). This is consistent with other reports of B. impatiens throughout its range (Cameron et al., 2011; Colla &amp; Packer, 2008; Colla et al., 2012). The UAAM collection holds two specimens collected between our historical and contemporary periods: Polk Co., June 4, 1963 and Saline Co., August 17, 1976. In the United States, B. impatiens is the only bumble bee species currently mass-reared for pollination services and has been commercially available since 1990 (Velthuis &amp; van Doorn, 2006). The ecological repercussions of commercial bumble bee trafficking are largely unknown. The greatest concern has been the potential for pathogen spillover, the transmission of diseases from commercial colonies to wild ones. Commercial bumble bee colonies are known to support heavier loads of pathogens, such as the intestinal protozoa Crithidia bombi Lipa &amp; Triggiani and Nosema bombi Fantham &amp; Porter, and parasites, such as the tracheal mite Locustacarus buchneri (Stammer), than their wild counterparts (Colla et al., 2006). Wild bees foraging near greenhouses in Canada which utilize commercial bumble bees are more likely to be infected with C. bombi and N. bombi than wild bees located far from greenhouses (Colla et al., 2006). This pathogen spillover from commercial bumble bees to wild populations may pose a threat to the stability of wild bumble bee populations. The commercial use of B. impatiens may also have another potential ecological impact that has remained unexplored: artificially increasing the local abundance of the commercial species through augmentation. If this were the case, we might expect B. impatiens to be less common in wildlands than in areas near agricultural development. Indeed, B. impatiens was rarely encountered in surveys of Arkansas grasslands from 2002 to 2008 (Warriner, 2011), in spite of its recent increase in county-level records. Whether or not the commercial trafficking of B. impatiens has influenced localized increases in Arkansas and elsewhere is unknown, but it is a notion that warrants further study.</p> <p>GLOSSA LENGTH: Short (4.74 ± 0.62 mm).</p> <p>ADULT ACTIVE PERIOD: Late season with an intermediate active period (75 days). Majority: mid-July through early October; Earliest: April 22; Latest: October 20.</p> <p>PREFERRED PLANTS: Solidago speciosa Nutt. (showy goldenrod, Asteraceae), Symphyotrichum Nees (aster, Asteraceae), S. integrifolium (wholeleaf rosinweed, Asteraceae), Solidago (goldenrod, Asteraceae), P. pilosum (Michx.) Pers. (whorled mountainmint, Lamiaceae), V. alternifolia (Linnaeus) Britt. ex Kearney (wingstem, Asteraceae), V. virginica (white crownbeard, Asteraceae), S. altissima (Canada goldenrod, Asteraceae), Salvia azurea Michx. ex Lam. (azure blue sage, Lamiaceae).</p> </div>	https://treatment.plazi.org/id/4A7B7945FFA4EB5A9AD0366D0F51FFC8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA3EB5A9AE3372D0F52F828.text	4A7B7945FFA3EB5A9AE3372D0F52F828.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Thoracobombus) pensylvanicus (De Geer 1773)	<div><p>Bombus (Thoracobombus) pensylvanicus (De Geer)</p> <p>‘American Bumble Bee’</p> <p>Bombus pensylvanicus [as B. americanorum (Fabricius)] was listed as the “most widespread and common species” in the state in Chandler &amp; McCoy’s (1965) study. Its statewide occurrence is much reduced today, although it remains widespread (Fig. 1). The contemporary occurrence of B. pensylvanicus (50%) is about one-third lower than its historic occurrence (82%, Fig. 3). Only a single record occurred in the period between our sampling intervals: Faulkner Co., September 6, 1976. This state-level pattern reflects what has also been observed throughout the range of B. pensylvanicus, and many sources consider B. pensylvanicus to be a declining species (Cameron et al., 2011; Colla &amp; Packer, 2008; Colla et al., 2012; Grixti et al., 2009). Although there are indications of a range-wide decline of B. pensylvanicus, it is likely that not all areas are reflecting the same shifts in abundance or occurrence. For example, B. pensylvanicus was abundant in the extreme south and western portions of its range (Louisiana, Oklahoma, and Texas) in recent surveys, although it was absent from much of the northern and eastern areas in which it was expected to occur (Cameron et al., 2011). Similarly, B. pensylvanicus was absent from the northern region of Illinois in recent surveys, although it was known from northern Illinois in historical records (Grixti et al., 2009). With contemporary records occurring throughout the state and in each ecoregion, we found no geographic pattern in the occurrences of B. pensylvanicus within Arkansas. This heterogeneity among regional studies highlights the utility of localized studies in determining the conservation status of species of interest.</p> <p>GLOSSA LENGTH: Long (6.41 ± 0.58 mm).</p> <p>ADULT ACTIVE PERIOD: Late season with a long active period (82 days). Majority: late June through mid-September; Earliest: May 13; Latest: October 16.</p> <p>PREFERRED PLANTS: Baptisia alba (wild white indigo, Fabaceae), Vernonia Schreb. (ironweed, Asteraceae), T. canadense (Canada germander, Lamiaceae), M. fistulosa (wild bergamot, Lamiaceae), A. esculentus (okra, Malvaceae), Solanum carolinense Linnaeus (Carolina horsenettle, Solanaceae), Cirsium discolor (Muhl. ex Willd.) Spreng. (field thistle, Asteraceae), S. azurea (azure blue sage, Lamiaceae), S. integrifolium (wholeleaf rosinweed, Asteraceae), V. villosa (winter vetch, Fabaceae).</p> </div>	https://treatment.plazi.org/id/4A7B7945FFA3EB5A9AE3372D0F52F828	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
4A7B7945FFA3EB5B9AD8334D0EC8FA48.text	4A7B7945FFA3EB5B9AD8334D0EC8FA48.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bombus (Psithyrus) variabilis (Cresson 1872)	<div><p>Bombus (Psithyrus) variabilis (Cresson)</p> <p>‘Variable Cuckoo Bumble Bee’</p> <p>Prior to our examination, only a single record of this species in Arkansas existed in the literature. Chandler &amp; McCoy (1965) listed a single record from Washington County, but without including any additional collection information. Three specimens of B. variabilis collected in Washington Co. during our target historical period were among the specimens in the UAAM collection (September, 1900; August 15, 1906; October 1, 1961), yet no specimens for our contemporary period were present (Fig. 1). However, three additional male specimens that were collected outside of our historical and contemporary periods are present in the UAAM. Two specimens were collected in the northwest portion of the state (Franklin Co., October 5, 1976 and Washington Co., September 29, 1993); the other was collected in eastern Arkansas (Desha Co., August 7, 1966). Bombus variabilis was not recovered in our surveys or in Warriner’s (2011) extensive Arkansas grassland surveys. With so few records, there is no suggestion of a change in the occurrence of B. variabilis between the historic (2.6%) and contemporary periods (0%, Fig. 3), and its status in the state remains unclear.</p> <p>Records for this species are both temporally and spatially sporadic throughout eastern North America (Williams et al., 2014). The species is a member of the social parasite subgenus Psithyrus Lepeletier, whose host is B. pensylvanicus. Its unusual life history may help explain its rarity. Lacking a foraging worker caste, species of Psithyrus are nest-bound and less likely to be encountered in typical field surveys. Also, as obligate nest parasites, their abundance is bound to be lower than that of their host. Still, there are indications that B. variabilis is declining and deserves further study. Its host, B. pensylvanicus, is also suspected to be on the decline (Cameron et al., 2011; Colla et al., 2012), and an obligate parasite is likely to follow the same population trends as its host. Across its range, B. variabilis has dramatically declined both in abundance relative to other species of Bombus and in geographic persistence, leading to a recommendation that it be classified as “critically endangered” (Colla et al., 2012). As in the case of B. fraternus, we urge that studies aiming to determine the conservation status of this rarer species take into consideration the inherent difficulties in accurately sampling species with low detectability before drawing conclusions on its stability.</p> <p>GLOSSA LENGTH: Unknown, not reported.</p> <p>ADULT ACTIVE PERIOD: Unknown, records in Arkansas from August–September.</p> <p>PREFERRED PLANTS: Unknown, not observed.</p></div> 	https://treatment.plazi.org/id/4A7B7945FFA3EB5B9AD8334D0EC8FA48	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Tripodi, Amber D.;Szalanski, Allen L.	Tripodi, Amber D., Szalanski, Allen L. (2015): The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 2015 (50): 1-17, DOI: 10.17161/jom.v0i50.4834, URL: http://dx.doi.org/10.17161/jom.v0i50.4834
