
Stephen BuchmannUniversity of Arizona | UA · Departments of Entomology and Department of Ecology and Evolutionary Biology
Stephen Buchmann
Ph.D. in Entomology (U.C. Davis)
About
151
Publications
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Introduction
I'm a pollination ecologist (Ph.D. in Entomology U.C. Davis). My research interests include nesting/mating biology of native bees, conservation, competition, chemical ecology, buzz pollination sound analyses, biomechanics of pollen release from poricidal anthers and anther anatomy. Currently, I'm part of a research group studying the brood cell microbiomes (bacteria, fungi) of solitary bees. I've published > 200 papers and ten books. My new book is What a Bee Knows from Island Press (DC).
Additional affiliations
April 1980 - October 2023
Position
- Adjunct Associate Professor of Entomology (Affiliate Scientist)
Description
- I no longer teach, but advise undergraduate, graduate (MS and Ph.D.) students and postdocs. Research Associate in Ecology and Evolutionary Biology. Adjunct Professor in Department of Entomology. Co-instructor for 22 years in the AMNH "The Bee Course" a bee taxonomy and ecology course at the SWRS, near Portal, AZ.
April 1979 - June 2000
Publications
Publications (151)
Foraging behavior frequently plays a major role in driving the geographic distribution of animals. Buzzing to extract protein-rich pollen from flowers is a key foraging behavior used by bee species across at least 83 genera (these genera comprise ~58% of all bee species). Although buzzing is widely recognized to affect the ecology and evolution of...
The evolution of tube-like floral morphologies that control pollen release via small openings (functionally poricidal flowers) represents a taxonomically and geographically widespread instance of repeated and independent evolution of a functionally similar morphology. Poricidal flowers are often closely associated with buzz pollination by bees, but...
Sex pheromones are species-specific chemical signals that facilitate the location, identification, and selection of mating partners. These pheromones can vary between individuals, and act as signals of mate quality. Here, we investigate the variation of male pheromones in the mesosomal glands of the large carpenter bee Xylocopa sonorina, within a N...
Host-microbe interactions underlie the development and fitness of many macroorganisms including bees. While many social bees benefit from vertically transmitted gut bacteria, solitary bees, which comprise the vast majority of species diversity within bees, lack a specialized gut microbiome. Here we examine the composition and abundance of bacteria...
Sex pheromones are species-specific chemical signals that facilitate the location, identification, and selection of mating partners. These pheromones can vary between individuals, and act as signals of mate quality. Here, we investigate the variation of male pheromones in the mesosomal glands of the large carpenter bee Xylocopa sonorina, within a N...
Pathogens and parasites of solitary bees have been studied for decades, but the microbiome as a whole is poorly understood for most taxa. Comparative analyses of microbiome features such as composition, abundance, and specificity, can shed light on bee ecology and the evolution of host–microbe interactions. Here we study microbiomes of ground-nesti...
Climate change, agricultural intensification, and other anthropogenic ecosystem challenges have caused declines in the diversity and abundance of insect pollinators. In response to these declines, entomologists have called for greater attention to insect pollinator conservation. Conservation primarily aims to protect groups of non-human animals—pop...
This chapter focuses on challenges and options in habitat restoration for solitary bees which account for 90% of bee species. As well as being important parts of local ecosystems, these species are pollinators of a wide range of crops such as alfalfa, tomato, eggplant and blueberries, cucurbit crops (such as pumpkin, squash and watermelon) as well...
The evolution of long-range pheromonal communication is often facilitated by morphological adaptations in glandular structures. Male carpenter bees (Xylocopa) in four subgenera possess hypertrophied sex pheromone glands responsible for their long-distance mate attraction. The valley carpenter bee (Xylocopa sonorina) is known for its “dispersed lek”...
Approximately 10% of flowering plant species conceal their pollen within tube-like poricidal anthers. Bees extract pollen from poricidal anthers via floral buzzing, a behavior during which they apply cyclic forces by biting the anther and rapidly contracting their flight muscles. The success of pollen extraction during floral buzzing relies on the...
An estimated 10% of flowering plant species conceal their pollen within tube-like anthers that dehisce through small apical pores (poricidal anthers). Bees extract pollen from poricidal anthers through a complex motor routine called floral buzzing, whereby the bee applies vibratory forces to the flower stamen by rapidly contracting its flight muscl...
An estimated 10% of flowering plant species conceal their pollen within tube-like anthers that dehisce through small apical pores (poricidal anthers). Bees extract pollen from poricidal anthers through a complex motor routine called floral buzzing, whereby the bee applies large vibratory forces to the flower stamen by rapidly contracting its flight...
Bees and other Hymenoptera utilize thorax vibration to realize an extensive range of behaviors ranging from flight to pollination. Strong indirect flight muscles contract to deform the thoracic walls and the resulting oscillation is sustained through a mechanism called stretch activation. While the mechanics of the insect thorax and muscles have be...
Alternative reproductive tactics (ARTs) occur when there is categorical variation in the reproductive strategies of a sex within a population. These different behavioral phenotypes can expose animals to distinct cognitive challenges, which may be addressed through neuroanatomical differentiation. The dramatic phenotypic plasticity underlying ARTs p...
We describe the nesting biology of Centris (Paracentris) burgdorfi, a solitary bee that nests in sandstone in northeastern Brazil. The nest consists of a shallow tunnel with access to the brood cells. Females of C. burgdorfi made 1–7 brood cells per nest with each cell requiring 2.58 ± 0.40 ( X¯ ± SD) days to construct. The average cell-building co...
Body size is an important trait linking pollinators and plants. Morphological matching between pollinators and plants is thought to reinforce pollinator fidelity, as the correct fit ensures that both parties benefit from the interaction. We investigated the influence of body size in a specialized pollination system (buzz‐pollination) where bees vib...
Sexual selection on male body size in species with a female-biased sexual size dimorphism is common yet often poorly understood. In particular, in the majority of bee species, the relative contribution of intrasexual competition and female choice to patterns of male body size is unknown. In this field study, we examined two possible components of m...
Floral sonication is a behaviour in which certain bees generate substrate-borne vibrations by contracting their flight muscles in order to extract pollen from poricidal anthers. Sonication vibrations, or ‘buzzes’, also contain a corresponding audible sound that results from vibrations radiating from the exoskeleton into the surrounding air. Acousti...
Figure S2. Maximum clade credibility tree from the time‐calibrated Beast phylogenetic analysis. Posterior probabilities are indicated above each branch.
Figure S3. Maximum clade credibility tree from the time‐calibrated Beast analysis. Error bars indicate the 95% Highest Posterior Density interval for the estimated age of each node. Numbers above each error bar indicate the mean of the estimated age.
Table S3. Prior probabilities of the minimum, maximum and mean age set for each calibration point along with the fossilized species and age of the fossil that the calibration point is based on.
Figure S1. Maximum clade credibility tree from the MrBayes phylogenetic analysis. Posterior probabilities are indicated above each branch and numbers in red circles show the placement of calibration points used in the divergence time analyses.
Table S2. GenBank numbers of sequences used for the phylogeny that were not from Cardinal and Danforth (2013).
Table S4. Sampling probabilities assigned to each clade to account for non‐random incomplete taxon sampling in the diversification rates analysis done using BAMM.
Table S1. List of taxa reported to sonicate flowers.
Over 22,000 species of biotically pollinated flowering plants, including some major agricultural crops, depend primarily on bees capable of floral sonication for pollination services. The ability to sonicate (“buzz”) flowers is widespread in bees but not ubiquitous. Despite the prevalence of this pollinator behavior and its importance to natural an...
Heteranthery is thought to reflect a division of labor, with some anthers serving a pollinator-feeding function and others serving a pollinating function. Mutualism theory predicts that each participant should try to maximize the benefit it receives from its partner: plants should allocate more pollen to pollination, and pollinators should collect...
The floral visitors of the boojum tree [Fouquieria columnaris (Kellogg) Kellogg ex Curran] in the Sierra Bacha, Sonora were studied and compared with Humphrey's data collected 30 years ago. The boojum, a species protected by CITES, has a distribution restricted to Baja California and the Sierra Bacha, Sonora. In the later locality, the richness of...
Bees foraging for floral rewards are one of our most thoroughly studied examples of generalist foraging ecology. Generalist bees rely considerably on instrumental (associative) learning to acquire routines that allow them to collect nectar efficiently from diverse plant species. Although such bees must also collect pollen from diverse species, few...
Pollinating animals (mostly bats, bees, beetles, birds, butterflies, flies, moths and wasps) provide almost incalculable economic and ecological benefits to humans, flowering plants and wildlife. Bees are the world's dominant pollinators, as the approximately 17 000 known bee species7 collectively interact with most of the planet's quarter million...
Do honey bees compete for food with other bee species in nature? This question has been the focus of considerable scientific and political attention in recent years, especially, but not exclusively in Australia. In this article we provide the background and rationale of the argument and present scientific studies which have attempted to provide evi...
Buzz pollination is a fairly well known syndrome arising convergently in angiosperms numerous times, but there has been little discussion about some basic aspects of the syndrome. For example, the presence of poricid anthers is a telltale sign of vibrational dehiscence, but how often has effective buzz pollination by insects been observed? If plant...
In Central Europe and other temperate regions the lipophilic bee hive product propolis normally originates from the bud exudate of poplar trees that is collected by the bees. Based on bee observations, various other sources have been discussed in particular for tropical regions, but in only few cases the origin has been proved by analytical methods...
The understanding of physiological and molecular processes underlying the sense of smell has made considerable progress during the past three decades, revealing the cascade of molecular steps that lead to the activation of olfactory receptor (OR) neurons. However, the mode of primary interaction of odorant molecules with the OR proteins within the...
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This research considered native Mayan stingless bees, Melipona beecheii, with special attention to decrease in their managed colonies. From a total of 155 beekeepers located in 60 communities, 58 were randomly selected to survey in 2011. Their experience ranged from less than one to 50 years, and initial colonies from one to 100. Both structured an...
Early successional landscapes along or adjacent to infrastructure installations have been highlighted as potential pollinator conservation zones that provide environmental benefits and ameliorate some of the negative impacts of wildland conversion. Habitat development and management initiatives in this field are active, but vetted support for parti...
During the past decade a few artists and even fewer entomologists discovered flatbed scanning technology, using extreme resolution graphical arts scanners for acquiring high magnification digital images of plants, animals and inanimate objects. They are not just for trip receipts anymore. The special attributes of certain scanners, to image thick o...
Males of Habropoda pallida searched for recently emerged females at a location in central Arizona where many females had nested in the preceding year. Patrolling males exhibited a variety of mate locating tactics ranging from inspecting existing emergence holes to patrolling flights around flowering creosote bush. These tactics appear to be under t...
This project provides information on new biological and pollination ecology for military natural resource managers to employ when managing their natural resources in accordance with their Integrated Natural Resource Management Plan (INRMP) as per the Sikes Act. Land managers can utilize findings from this project to help plan, conserve, protect and...
and Summary
The post–insemination display of males of the anthophorid bee, Centris pallida , is described with special reference to its acoustical component. Males of the anthophorid bee Centris pallida do not release their mates immediately after having transferred sperm to them but instead engage in a complex post–insemination display involving t...
Within the past 5 to 10 years, pollinating animals and rare plants have become the focus of new programs and priorities by the Department of Defense (DoD) along with other federal land management and research agencies and Non-Government Organization (NGO) conservation and restoration organizations. Laurie Davies Adams, Executive Director of the Pol...
Bombus sonorus Say (Hymenoptera: Apidae) forages for nectar and pollen at a wide variety of flowers of desert plants (Milliron, 1973; Hurd and Linsley, 1975) and, as most bumble bees around the world, is catholic in its floral choices. Although bumble bees may use nutritional sources other than flowers, for example by puddling at damp patches of so...
Large numbers of males of the bee Centris pallida Fox have been observed patrolling areas in which females are emerging. Males locate specific sites at which a buried bee is about to emerge and dig down to meet the other individual, male or female. If it is a female, mating is initiated when she scrambles into the excavation pit created by the male...
A major goal of population biologists involved in restoration work is to restore populations to a level that will allow them to persist over the long term within a dynamic landscape and include the ability to undergo adaptive evolutionary change. We discuss five research areas of particular importance to restoration biology that offer potentially u...
Carpenter bees ( Xylocopa californica arizonensis ) in west Texas, U.S.A., gather pollen and ‘rob’ nectar from flowers of ocotillo ( Fouquieria splendens ). When common, carpenter bees are an effective pollen vector for ocotillo. We examined ocotillo's importance as a food source for carpenter bees.
The visitation rate of carpenter bees to ocotillo...
Data on worker traffic, size and concentration of nectar loads, and size and composition of pollen loads were collected for a colony of Bombus pennsylvanicus sonorus Say in the Chihuahuan Desert in Arizona, U.S.A.
Foraging activity increased through the morning to a peak level in early afternoon and then declined steadily thereafter. Pollen collect...
Plants in many genera of Iridaceae, Krameriaceae, Malpighiaceae, Orchidaceae and Scrophulariaceae possess specialised oil-secreting organs (elaiophores), and genera of Cucurbitaceae, Melastomataceae, Solanaceae, Primulaceae and Gesneriaceae may contain oil flowers, which are found most abundantly in neotropical savannas and forests. Oil flowers are...
The floral biology of night-blooming Peniocereus cacti and Datura plants was studied in North America's Sonoran Desert. In populations of two rare cactus species ( Peniocereus greggii and Peniocereus striatus), individual plants bloom synchronously on less than five nights per year and are self-incompatible. In contrast, the abundant Datura discolo...
Previous studies have shown that the nectar-feeding bat, Leptonycteris curasoae, is the major pollinator of Pachycereus pringlei (cardon), a columnar cactus whose populations are either gynodioecious or trioecious in the Sonoran Desert. On the basis of evidence of pollinator limitation in females and low flower visitation rates, a hypothesis has be...
Vibration accelerations and displacements were measured in Bombus spp., Xylocopa spp., Apis mellifera L., and Eristalis tenax (L.) (a syrphid flower fly) including the first measurements of thoracic displacements during untethered free flight, and floral sonication by Bombus terrestris (L.). For all except A. mellifera the thoracic displacement dur...
Pollen ranges from 2.5% to 61% protein content. Most pollen proteins are likely to be enzymes that function during pollen tube growth and subsequent fertilization, but the vast range of protein quantity may not reflect only pollen-pistil interactions. Because numerous vertebrate and invertebrate floral visitors consume pollen for protein, protein c...
Mature pollen possesses or lacks starch grains. Many wind-pollinated and self-pollinated species possess starch grains. This apparent association has led some researchers to hypothesize that starchiness of pollen is functionally related to pollen consumption by pollinators. This hypothesis assumes that starchy pollens contain less oil than starchle...
Following reports of dramatic declines in managed and feral honey bees from nearly every region of North America, scientists and resource managers from the U.S., Mexico, and Canada come together to review the quality of the evidence that honey bees as well as other pollinators are in long-term decline and to consider the potential consequences of t...
Following reports of dramatic declines in managed and feral honeybees from nearly every region of North America, scientists and resource managers from the US, Mexico and Canada came togther to review the quality of evidence that honey bees as well as other pollinators are in long-term decline and to consider the potential consequences of these loss...
The indirect flight muscles of bees are used to produce a variety of actions in addition to flight, including sonication, which has a higher frequency than flight. We observed the dynamic movement of the scutum during sonication and the transition from tethered flight to sonication. During sonication, the scutum oscillated above its rest position,...
1. Sonication is a seemingly effective method for foraging insects to extract pollen rapidly from poricidal anthers. However, without a dispensing mechanism to limit the pollen extraction a single forager might be able to glean all of the pollen from a flower in a single visit. 2. The vibratory release mechanism of a buzz-pollinated flower species,...
Do honey bees compete for food with other bee species in nature? This question has been the focus of considerable scientific and political attention in recent years, especially, but not exclusively in Australia. In this article we provide the background and rationale of the argument and present scientific studies which have attempted to provide evi...
Consider this: Without interaction between animals and flowering plants, the seeds and fruits that make up nearly eighty percent of the human diet would not exist.In The Forgotten Pollinators, Stephen L. Buchmann, one of the world's leading authorities on bees and pollination, and Gary Paul Nabhan, award-winning writer and renowned crop ecologist,...
Although Rhododendron spp. anthers have apical pores and should be expected to be buzz pollinated, bees do not normally sonicate them to release pollen. Stamens were examined to determine their pollen release mechanism; the filaments were shown to have natural vibration modes that cause pollen to be forcibly ejected by vibration, providing the poll...
A hypothesis is proposed and field data presented indicating that in long-distance navigation, honey bee foragers use horizon landmarks to determine the direction of their home site. Metal tags were recaptured from marked foragers released at various distances and directions from their nests located in mountainous or flat terrain. The proportion of...
Although Rhododendron spp. anthers have apical pores and should be expected to be buzz pollinated, bees do not normally sonicate them to release pollen. Stamens were examined to determine their pollen release mechanism; the filaments were shown to have natural vibration modes that cause pollen to be forcibly ejected by vibration, providing the poll...
1. The genus Prosopis consists of woody leguminous trees and shrubs of interest for fuelwood and agroforestry purposes in arid and semi-arid regions. Prosopis velutina is common to the south-western United States and northern Mexico. Its flowers are an important food source for several native insects, as well as Apis mellifera used in the honey ind...
During their complex foraging trails, central place foragers often integrate distances traveled and angles turned to update continuously their estimation of home direction. This system, called path integration, allows them to head directly home even from an unfamiliar site [i]. Path integration has been particularly well studied in ants [21. Honeyb...
Males of many bees in the subfamily Nomiinae (Halictidae) have numerous secondary sexual characters, which provide much systematic information. Similarly, the use of these structures by males during sexual behaviour may provide useful characters, but the courtship and copulatory behaviour of most of these bees is not known. Structures and behaviour...
Sugar concentration in nectar foraged by 13 Euglossini, 16 Meliponini and 8 Centridini (Apidae) was monitored in floristically rich habitats. For 6 Meliponini, sugar solution profitability by imbibement rate was compared to nectar choice (figs 1-4, tables I-IV). In addition, foraging assays tested meliponine response to 10 amino acid solutions (tab...
The phenological relationships between nesting behavior of a specialist, solitary bee, Dieunomia triangulifera, and the flowering of its primary pollen source, Helianthus annuus, were studied for 3 yr at a site in northeastern Kansas, which contained between 50 000 and >150 000 nests. Activity patterns of D. triangulifera are closely synchronized w...
We describe the breeding system of an autotetraploid trioecious cactus, Pachycereus pringlei, provide estimates of the fitnesses of males and females relative to that of hermaphrodites, and discuss the role played by pollinators in the maintenance of three sexual morphs. Relatively high frequencies of females (45%) and males (26%) exist in coastal...