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Of the 265 known bumble bee (Bombus) species, knowledge of colony lifecycle is derived from relatively few species. As interest in Bombus commercialization and conservation grows, it is becoming increasingly important to understand colony growth dynamics across a variety of species since variation exists in nest success, colony growth, and reproductive output. In this study, we reported successful nest initiation and establishment rates of colonies and generated a timeline of colony development for 15 western North American Bombus species, which were captively reared from wild-caught gynes from 2009 to 2019. Additionally, we assessed variation in colony size among 5 western North American Bombus species from 2015 to 2018. Nest initiation and establishment rates varied greatly among species, ranging from 5–76.1% and 0–54.6%, respectively. Bombus griseocollis had the highest rates of nest success across the 11-yr period, followed by B. occidentalis , B. vosnesenskii , and B. huntii. Furthermore, days to nest initiation and days to nest establishment varied among species, ranging from 8.4 to 27.7 days and 32.7 to 47 days. Colony size also differed significantly among species with B. huntii and B. vosnesenskii producing more worker/drone cells than B. griseocollis , B. occidentalis , and B. vancouverensis. Additionally, gyne production differed significantly among species with B. huntii colonies producing more gynes than B. vosnesenskii. Results from this study increase knowledge of systematic nesting biology for numerous western North American Bombus species under captive rearing conditions, which can further improve rearing techniques available to conservationists and researchers. [ABSTRACT FROM AUTHOR]

Environmental heterogeneity resulting from human-modified landscapes can increase intraspecific trait variation. However, less known is whether such phenotypic variation is driven by plastic or adaptive responses to local environments. Here, we study five bumble bee (Apidae: Bombus) species across an urban gradient in the greater Saint Louis, Missouri region in the North American Midwest and ask: (1) Can urban environments induce intraspecific spatial structuring of body size, an ecologically consequential functional trait? And, if so, (2) is this body size structure the result of plasticity or adaptation? We additionally estimate genetic diversity, inbreeding, and colony density of these species—three factors that affect extinction risk. Using ≥ 10 polymorphic microsatellite loci per species and measurements of body size, we find that two of these species (Bombus impatiens, Bombus pensylvanicus) exhibit body size clines across the urban gradient, despite a lack of population genetic structure. We also reaffirm reports of low genetic diversity in B. pensylvanicus and find evidence that Bombus griseocollis, a species thought to be thriving in North America, is inbred in the greater Saint Louis region. Collectively, our results have implications for conservation in urban environments and suggest that plasticity can cause phenotypic clines across human-modified landscapes. [ABSTRACT FROM AUTHOR]

Females and males often face different sources of selection, resulting in dimorphism in morphological, physiological, and even cognitive traits. Sex differences are often studied in respect to spatial cognition, yet the different ecological roles of males and females might shape cognition in multiple ways. For example, in dietary generalist bumblebees (Bombus), the ability to learn associations is critical to female workers, who face informationally rich foraging scenarios as they collect nectar and pollen from thousands of flowers over a period of weeks to months to feed the colony. While male bumblebees likely need to learn associations as well, they only forage for themselves while searching for potential mates. It is thus less clear whether foraging males would benefit from the same associative learning performance as foraging females. In this system, as in others, cognitive performance is typically studied in lab-reared animals under captive conditions, which may not be representative of patterns in the wild. In the first test of sex and species differences in cognition using wild bumblebees, we compared the performance of Bombus vancouverensis nearcticus (formerly bifarius) and Bombus vosnesenskii of both sexes on an associative learning task at Sierra Nevada (CA) field sites. Across both species, we found that males and females did not differ in their ability to learn, although males were slower to respond to the sucrose reward. These results offer the first evidence from natural populations that male bumblebees may be equally as able to learn associations as females, supporting findings from captive colonies of commercial bees. The observed interspecific variation in learning ability opens the door to using the Bombus system to test hypotheses about comparative cognition. [ABSTRACT FROM AUTHOR]

The introduction of exotic species can have profound impacts on mutualisms between native species in invaded areas. However, determining whether a new invader has impacted native species depends on accurately reconstructing the invasion timing. The arrival of Africanized honey bees (AHB) in southern Utah at some point between 1994 and 2011 has recently been implicated in the local extinction of Perdita meconis, a native specialist pollinator of an endangered poppy, Arctomecon humilis. Although AHBs were purportedly first detected in southern Utah in 2008, their presence in nearby Nevada, Arizona, and New Mexico by 1998–2001 suggests that they may have been present in Utah much earlier. We refined the arrival date of AHBs in southern Utah by using a molecular marker to determine maternal ancestry of museum specimens collected between 2000 and 2008. We found that AHBs were present in southern Utah from 2000 onwards, advancing the arrival date of this invader by at least 8 years. This lends credence to the hypothesis that AHBs played a critical role in the local extinction of P. meconis in Utah. This work also highlights the importance of vouchering even common species such as honey bees in museum collections to serve future research needs. [ABSTRACT FROM AUTHOR]

Aim: Bumble bees (Hymenoptera: Apidae: Bombus) are economically and ecologically important pollinators in agroecosystems and wildland habitats. In the Nearctic region, there are approximately 41 species, of which the IUCN lists twelve species as vulnerable, endangered, or critically endangered. We conducted a standardized faunal survey to inform ongoing conservation efforts including petitions under review for the Endangered Species Act. Furthermore, we test the appropriateness of a methodology for accurately sampling bumble bee communities. Location: The United States of America, including 31 sites in 15 states. Methods: We surveyed 15 states in the summer of 2015 to assess community composition and relative species abundance at agricultural and seminatural sites throughout the United States. We collected approximately 100 bees, using aerial nets, from each of 31 sites and identified specimens to species, totaling 3,252 bees. We assessed our survey methodology to understand whether it accurately sampled the potential community of bumble bees at each site for utility in future monitoring efforts. Results: Average site species richness was 5.1 ± 2.05, and we detected 30 of the 41 species documented historically within the contiguous United States. Sampling a site beyond 100 bees rarely added additional species detections, whereas adding additional sampling sites within an ecoregion frequently increased the species richness for the ecoregion. Thirteen of the 30 species we detected each accounted for <1% of the total fauna, and two species accounted for 49.02% of all bees captured. Species richness and evenness increased with increasing latitude across communities. Main Conclusions: Species diversity and evenness in bumble bees increases in northern latitudes and increasing elevation in the United States; however, a few common species tend to dominate communities while many species occur only in low numbers. The results of this survey effort can inform current conservation evaluations and planning. Bumble bee communities vary across the United State and several species are considered to be at risk. We assessed the community structure and evaluated a sampling technique at 31 sites in 15 states in 2015. We suggest that sampling methods were adequate to assess community structure and provide much needed baseline data for further monitoring efforts. [ABSTRACT FROM AUTHOR]

Studies of bee movement and activities across a landscape are important for developing an understanding of their behavior and their ability to withstand environmental stress. Recent research has shown that proteins, such as egg albumin, are effective for mass-marking bees. However, current protein mass-marking techniques require sacrificing individual bees during the data collection process. A nonlethal sampling method for protein mark-capture research is sorely needed, particularly for vulnerable, sensitive, or economically valuable species. This study describes a nonlethal sampling method, in which three non-Apis bee species (Bombus bifarius Cresson [Hymenoptera: Apidae], Osmia lignaria Say [Hymenoptera: Megachilidae], and Megachile rotundata Fabricius [Hymenoptera: Megachilidae]) were tested for a unique protein marker by immersing them momentarily in saline buffer and releasing them. Results showed that an egg albumin-specific enzyme-linked immunosorbent assay was 100% effective at detecting the protein on bees that were sampled nonlethally. Furthermore, this sampling method did not have an impact on bee survivorship, suggesting that immersing bees in buffer is a reliable and valid surrogate to traditional, destructive sampling methods for mark-capture bee studies. [ABSTRACT FROM AUTHOR]

Crithidia bombi and Crithidia expoeki (Trypanosomatidae) are common parasites of bumble bees ( Bombus spp.). Crithidia bombi was described in the 1980s, and C. expoeki was recently discovered using molecular tools. Both species have cosmopolitan distributions among their bumble bee hosts, but there have been few bumble bee studies that have identified infections to species since the original description of C. expoeki in 2010. Morphological identification of species is difficult due to variability within each stage of their complex lifecycles, although they can be easily differentiated through DNA sequencing. However, DNA sequencing can be expensive, particularly with many samples to diagnose. In order to reliably and inexpensively distinguish Crithidia species for a large-scale survey, we developed a multiplex PCR protocol using species-specific primers with a universal trypanosomatid primer set to detect unexpected relatives. We applied this method to 356 trypanosomatid-positive bumble bees from North America as a first-look at the distribution and host range of each parasite in the region. Crithidia bombi was more common (90.2%) than C. expoeki (21.3%), with most C. expoeki -positive samples existing as co-infections with C. bombi (13.8%). This two-step detection method also revealed that 2.2% samples were positive for trypanosmatids that were neither C. bombi nor C. expoeki. Sequencing revealed that two individuals were positive for C. mellificae , one for Lotmaria passim , and three for two unclassified trypanosomatids. This two-step method is effective in diagnosing known bumble bee infecting Crithidia species, and allowing for the discovery of unknown potential symbionts. [ABSTRACT FROM AUTHOR]

In hyper-diverse groups such as Hymenoptera, a variety of structures with different, complementary functions are used for feeding. Although the function of the parts such as the mandibles is obvious, the use of others, like the labrum, are more difficult to discern. Here, we discuss the labrum's function in bees, as well as the implications of deformities to this and associated characteristics. [ABSTRACT FROM AUTHOR]

A Polymerase Chain Reaction (PCR) molecular diagnostic survey for the honey bee pathogens Nosema apis Zander and N. ceranae Fries was conducted on feral Africanized honey bee (AHB) and European honey bee (EHB), Apis mellifera L., populations sampled from Mississippi, Arkansas, Texas, Utah, Oklahoma, and New Mexico. Polymerase Chain Reaction - Restriction Fragment Length polymorphism (PCR-RFLP) analysis of a 220 bp small subunit (SSU) marker was conducted on 517 samples, consisting of 245 AHB and 272 EHB individuals. A total of 43 samples (8.3%) were positive for Nosema; of these, 82.1% were N. ceranae, and the remainder were N. apis. No mixed samples were observed. For the AHB samples, Nosema was detected in 9.0% of the samples with 89.5% of the Nosema identified as N. ceranae, and 10.5% as N. apis. With the EHB samples, 7.7% had Nosema; 75.0% of these with N. ceranae, and 25.0% with N. apis. No significant difference was observed between AHB and EHB feral samples for occurrence of each Nosema species and prevalence of Nosema infection. Among the AHB samples, Nosema was more common in Utah and Texas than in New Mexico and Oklahoma. Nosema infection rates for feral honey bees was considerably lower than levels observed with managed honey bees in studies from New York, South Dakota, and Virginia. [ABSTRACT FROM AUTHOR]

The article discusses a study on the prevalence of trypanosomatid and Nosema bombi in spring bumble bee queens in Kansas. Topics covered include the surveys of bumble bee pathogens in the U.S., the importance of bumble bees as native pollinators in temperate regions, and the greater scrutiny warranted by the Kansas populations of Bombus pensylvanicus and B. auricomus.

Existing taxonomic studies of Reticulitermes spp. (Isoptera: Rhinotermitidae) from California provide information on only two described species: Reticulitermes hesperus Banks and Reticulitermes tibialis Banks. However, while conducting a genetic evaluation of the genus from North America, we find evidence of species that cannot be identified morphologically with existing information. We also update more current information about other species detected during our investigations, including the positive identification of R. flavipes from California. Therefore, we have conducted a molecular genetics study involving DNA sequencing of a portion of the mitochondrial DNA (mtDNA) 16S gene to determine the extent of genetic variation within Reticulitermes from California. We analyzed 94 samples. Twenty-five nucleotide sites were variable in R. hesperus, and 19 mtDNA haplotypes were observed in the 428-bp mtDNA sequence. Fourteen haplotypes (37%) occurred only once, whereas the most common haplotypes, HE4 and HE9, each occurred in 18% of the samples. Although some haplotypes were found to have a broad geographical range across the state, some were restricted to the southern region, as were all samples identified as R. tibialis. Twelve haplotypes of an undescribed western species, R. n. sp. 'R. okanaganensis,' were found, and its distribution throughout the state is discussed. Additionally, genetic evidence of two additional undescribed Reticulitermes species from southern California is presented. [ABSTRACT FROM AUTHOR]

The Mojave Desert of the southwestern U.S. is home to two protected species of poppy in the genus Arctomecon Torr. & Frém. (Papaveraceae). A pollinator of these species is the specialist bee Perdita meconis Griswold (Andrenidae) a specialist on poppy pollen.Recently, the easternmost population of P. meconis, which was associated with A. humilis Coville in Utah, has become locally extinct, and other historically associated bee pollinators have become scarce. Implicated in the disruption of this pollination system is invasion by the Africanised honey bee.Here we report on the status of P. meconis in historic populations associated with congener A. californica Torr. & Frém., 100 km west in Clark Co., Nevada where the Africanised honey bee is also adventive.We surveyed flower visitors at eight A. californica populations in 2017, six of which had been surveyed in 1995. In general, we found no disruptions of the historic pollination system of A. californica despite the presence of abundant Africanised honey bees, which largely foraged at other flower species.The most likely cause of the disparate effects of the Africanised honey bee in Utah and Nevada is livestock grazing. Grazing in Utah has been continuous for over three decades and while cattle do not graze A. humilis, they graze its floral competitors, forcing honey bees to forage on poppy flowers. In Nevada, protections afforded to the desert tortoise halted grazing approximately when the Africanised honey bee invaded, making diverse floral forage available for honey bees. [ABSTRACT FROM AUTHOR]

The article discusses Xylocopa (X) virginica L. and X. micans Lepeletier, two species in the genus Xylocopa Latreille that are known to occur in the Eastern U.S. Two males of X. micans were netted on May 10, 2010 north of Biscoe in Prairie County, Arkansas. The range of X. virginica extends through much of the Eastern U.S. It has been noted that the role of X. micans as generalist pollinator with special abilities can be an important factor in plant communities.