A simple and distinctive microbiota exclusively associated with honey bees and bumble bees

Abstract: Specialized relationships with bacteria often allow animals to exploit a new diet by providing a novel set of metabolic capabilities. Bees are a monophyletic group of Hymenoptera that transitioned to a completely herbivorous diet from the carnivorous diet of their wasp ancestors. Recent culture-independent studies suggest that a set of distinctive bacterial species inhabits the gut of the honey bee, Apis mellifera. Here we survey the gut microbiotae of diverse bee and wasp species to test whether acquisition of these bacteria was associated with the transition to herbivory in bees generally. We found that most bee species lack phylotypes that are the same or similar to those typical of A. mellifera, rejecting the hypothesis that this dietary transition was symbiont-dependent. The most common bacteria in solitary bee species are a widespread phylotype of Burkholderia and the pervasive insect associate, Wolbachia. In contrast, several social representatives of corbiculate bees do possess distinctive bacterial phylotypes. Samples of A. mellifera harboured the same microbiota as in previous surveys, and closely related bacterial phylotypes were identified in two Asian honey bees (Apis andreniformis and Apis dorsata) and several bumble bee (Bombus) species. Potentially, the sociality of Apis and Bombus species facilitates symbiont transmission and thus is key to the maintenance of a more consistent gut microbiota. Phylogenetic analyses provide a more refined taxonomic placement of the A. mellifera symbionts. apis mellifera | bacterial microbiota | insect symbiosis | microbiology | molecula

Phylogeny, biogeography and diversification of the mining bee family Andrenidae

peer reviewedThe mining bees (Andrenidae) are a major bee family of over 3000 described species with a nearly global distribution. They are a particularly significant component of northern temperate ecosystems and are critical pollinators in natural and agricultural settings. Despite their ecological and evolutionary significance, our knowledge of the evolutionary history of Andrenidae is sparse and insufficient to characterize their spatiotemporal origin and phylogenetic relationships. This limits our ability to understand the diversification dynamics that led to the second most species-rich genus of all bees, Andrena Fabricius, and the most species-rich North American genus, Perdita Smith. Here, we develop a comprehensive genomic dataset of 195 species of Andrenidae, including all major lineages, to illuminate the evolutionary history of the family. Using fossil-informed divergence time estimates, we characterize macroevolutionary dynamics, incorporate paleoclimatic information, and present our findings in the context of diversification rate estimates for all other bee tribes. We found that diversification rates of Andrenidae steeply increased over the past 15 million years, particularly in the genera Andrena and Perdita. This suggests that these two groups and the brood parasites of the genus Nomada Scopoli (Apidae), which are the primary cleptoparasitic counterparts of Andrena, are similar in age and represent the fastest diversifying lineages of all bees. Using our newly developed time frame of andrenid evolution, we estimate a late Cretaceous origin in South America for the family and reconstruct the past dispersal events that led to its present-day distribution.15. Life on lan

Pollinator assemblage and pollen load differences on sympatric diploid and tetraploid cytotypes of the desert-dominant Larrea tridentata

PREMISE: Whole-genome duplication (polyploidy) is an important force shaping flowering plant evolution. Ploidy-specific plant–pollinator interactions represent important community-level biotic interactions that can lead to nonrandom mating and the persistence of mixed-ploidy populations. METHODS: At a naturally occurring diploid–tetraploid contact zone of the autopolyploid desert shrub Larrea tridentata, we combined flower phenology analyses, collections of bees on plants of known cytotype, and flow cytometry analyses of bee-collected pollen loads to investigate whether (1) diploid and tetraploid plants have unique bee pollinator assemblages, (2) bee taxa exhibit ploidy-specific visitation and pollen collection biases, and (3) specialist and generalist bee taxa have ploidy-specific visitation and pollen collection biases. RESULTS: Although bee assemblages overlapped, we found significant differences in bee visitation to co-occurring diploids and tetraploids, with the introduced honeybee (Apis mellifera) and one native species (Andrena species 12) more frequently visiting tetraploids. Consistent with bee assemblage differences, we found that diploid pollen was overrepresented among pollen loads on native bees, while pollen loads on A. mellifera did not deviate from the random expectation. However, mismatches between the ploidy of pollen loads and plants were common, consistent with ongoing intercytotype gene flow. CONCLUSIONS: Our data are consistent with cytotype-specific bee visitation and suggest that pollinator behavior contributes to reduced diploid–tetraploid mating. Differences in bee visitation and pollen movement potentially contribute to an easing of minority cytotype exclusion and the facilitation of cytotype co-occurrence

Pollinator assemblage and pollen load differences on sympatric diploid and tetraploid cytotypes of the desert-dominant \u3ci\u3eLarrea tridentata\u3c/i\u3e

PREMISE: Whole-genome duplication (polyploidy) is an important force shaping flowering-plant evolution. Ploidy-specific plant–pollinator interactions represent important community-level biotic interactions that can lead to nonrandom mating and the persistence of mixed-ploidy populations. METHODS: At a naturally occurring diploid–tetraploid contact zone of the autopolyploid desert shrub Larrea tridentata, we combined flower phenology analyses, collections of bees on plants of known cytotype, and flow cytometry analyses of bee-collected pollen loads to investigate whether (1) diploid and tetraploid plants have unique bee pollinator assemblages, (2) bee taxa exhibit ploidy-specific visitation and pollen collection biases, and (3) specialist and generalist bee taxa have ploidy-specific visitation and pollen collection biases. RESULTS: Although bee assemblages overlapped, we found significant differences in bee visitation to co-occurring diploids and tetraploids, with the introduced honeybee (Apis mellifera) and one native species (Andrena species 12) more frequently visiting tetraploids. Consistent with bee assemblage differences, we found that diploid pollen was overrepresented among pollen loads on native bees, while pollen loads on A. mellifera did not deviate from the random expectation. However, mismatches between the ploidy of pollen loads and plants were common, consistent with ongoing intercytotype gene flow. CONCLUSIONS: Our data are consistent with cytotype-specific bee visitation and suggest that pollinator behavior contributes to reduced diploid–tetraploid mating. Differences in bee visitation and pollen movement potentially contribute to an easing of minority cytotype exclusion and the facilitation of cytotype co-occurrence

Natural history specimens collected and/or identified and deposited.

Natural history specimen data collected and/or identified by Robert L. Minckley, <a href="https://orcid.org/0000-0002-1217-7693">https://orcid.org/0000-0002-1217-7693</a>. Claims or attributions were made on Bionomia, <a href="http://bionomia.net">https://bionomia.net</a> using specimen data from the Global Biodiversity Information Facility, <a href="https://gbif.org">https://gbif.org</a>

Solitary wasps: behavior and natural history by Kevin M. O'Neill

Journal ArticleMost species of living things are insects, and ter- restrial ecology consists largely of interactions between insects and plants. The biologies of major insect groups such as Hymenoptera should be well documented and well known. Amazingly, they are not. The world is awash in excellent reviews of cur- rent knowledge about the much less diverse and less ecologically significant mammals and bird

Polyploid speciation in the North American creosote bush (Larrea tridentata: Zygophyllaceae)

Thesis (Ph. D.)--University of Rochester. Dept. of Biology, 2013.Autopolyploidy (intra-lineage genome duplication) is a common form of chromosome evolution in plants that generates strong post-zygotic reproductive isolation. Though widely regarded as a mechanism of speciation, diploids and autopolyploids are rarely considered unique species because chromosome duplication occurs quickly and rarely generates clear-cut morphological differences or reciprocal monophyly. Moreover, the significance of ecologically-mediated pre-zygotic barriers to polyploid speciation is debated among evolutionary biologists. The creosote bush (Larrea tridentata, Zygophyllaceae), a dominant species of the North American desert flora comprising three cytotypes spread across the Chihuahuan, Sonoran, and Mojave Deserts, is regarded as a classical example of autopolyploid speciation. Utilizing L. tridentata as a natural experiment, I addressed major conceptual issues in speciation research and answered longstanding ecological and taxonomic questions pertaining to this North American desert keystone species. In Chapter 1, I leverage flow cytometry, as well as plastid and nuclear DNA molecular sequences, to investigate the cytogeography and evolutionary history of the L. tridentata chromosome races. In Chapter 2, I investigate hypotheses of ecological adaptation and niche conservatism among ploidy levels based on computational niche modeling. Next, in Chapter 3, I address the issue of morphological differentiation and taxonomic recognition of autopolyploids using morphometric measurements and statistical analyses of co-occurring cytotypes. Finally, in Chapter 4, I build on findings from Chapters 1-3 to test the strength of inter-cytotype reproductive isolation (based on field observations and experiments) and realized gene flow (based on cpDNA sequence data and Amplified Fragment Length Polymorphisms). This research demonstrates that creosote bush cytotypes diverged recently (late-Pliocene or Pleistocene) and experienced rapid demographic expansion, but are nonetheless, now found in ecologically distinct habitats. The cytotypes are morphologically similar but can be differentiated in sympatry by floral and leaf characters. Ploidy is important for preventing intercytotype gene flow in sympatry, but the occurrence of occasional F1 hybrids (triploids, pentaploids) and “cryptic” tetraploid F1 hybrids (derived by unilateral sexual polyploidization) suggests low levels of continuing gene flow. Although habitat isolation is a major factor preventing intercytotype hybridization, triploid block appears very effective in preventing hybridization in sympatry. Diploids and tetraploids are more strongly reproductively isolated, and more genetically differentiated, than tetraploids and hexaploids, however, the cytotypes represent distinct lineages that should be recognized at the subspecies level

A cladistic analysis and classification of the subgenera and genera of the large carpenter bees, tribe Xylocopini (Hymenoptera: Apidae) /

no.

Nesting Biology of Glenostictia pictifrons (F. Smith) (Hymenoptera: Sphecidae: Bembicini)

A population of Glenostictia pictifrons in Kansas practices progressive provisioning, using Diptera of at least 7 families as prey. Nests have a single terminal cell at a mean depth of 4. 1 cm, which is also the average depth at which the shallow soil is underlain by bedrock at this nesting site. Adult females provision one nest at a time, spending a mean of 5.5 days per nest. The wasps make an outer closure when away from the nest, but no inner closure, and neither sex spends the night or periods of inclement weather inside nests. Wasps do not level mounds while digging or after completion of a new nest, although the mound is completely levelled during final closure. The egg is laid erect on the base of the wing of the first prey placed in the cell, and the cocoon has an outer shroud of silk embedded with prey remains. Circumstantial evidence suggests nest parasitism by the mutillid wasp Dasy mutilla quadriguttata (Say)