This post comes from Cliff Brock, who is a graduate student in the Contreras (plant breeding), Langellotto (pollinators), and Lambrinos (invasive plants) lab groups. Cliff is studying the impact that plant breeding has on invasiveness and pollinator visits in butterfly bush (Buddleja davidii) and its cultivars. Having three co-advisors can be extremely challenging. However, Cliff has been a true joy to work with, and seems to have navigating the complexities of three labs, quite well.
Cliff decided to write about flies as pollinators. When I asked him why he wanted to write about flies, he mentioned that they usually pollinate flowers that have foul smells, or that may not be as attractive as other flowering plants. He said that he has a special place in his heart for these ‘botanical underdogs’ ~ a sentiment that I thought was sincerely sweet.
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While bees deservedly get most of the attention regarding their pollination services, many of our most important crops and wildflowers are primarily pollinated by flies. Generally speaking, fly-pollinated flowers are dark maroons to reds and emit earthy, fermented, or putrid aromas. The coevolution of plants and flies has resulted in some of the most amazing and unusual flowers. The largest flowers in the word, Amorphophallus and Rafflesia, are almost exclusively pollinated by flies and beetles.And even our beloved chocolate requires a small midge fly for its sole pollinator.
Rafflesia is a genus of parasitic plants from SE Asia. Some have blooms 39″ in diameter. Photo Source: https://en.wikipedia.org› wiki › Rafflesia
Here in the US, many of our most beloved spring ephemerals have coevolved with flies. While many Trillium are bee pollinated (e.g. the abundant white Trillium ovatum), species with red and brown flowers are primarily pollinated by fungus gnats. The iconic American pawpaw (Asimina triloba), which has seen a resurgence in popularity, smells of rotting flesh and is irresistible to a whole host of fly species.
Here we see Trillium erectum (or stinking Benjamin) absolutely covered with fungus gnats. Photo from Brooklyn Botanic Garden
Asarum, or wild ginger, is a generally diminutive herbaceous plant often grown as a groundcover. The odd flowers are born close to the ground and are usually hidden from human view. Yet I find them particular beautiful, and every year I look forward to rediscovering them beneath the mottled foliage. Asarum takes fungal mimicry to a new level. Panda ginger, one of the Asian species, is especially funky. The flowers mimic the colors, textures, and smells of toadstools.
Asarum maximum (as seen on the left)might have evolved to mimic a woodland fungus somewhat like the black morel, below. Wild ginger photo from Plant Delights Nursery. Morel photo from Ohio mushroom society.
Every June – August, from 2017-2019, we collected bees from 25 Portland area gardens. As I start to build out a Bee Guide for Portland Gardens, I wanted to highlight some of the notable bees that we collected. We are still waiting for our 2019 bees to be identified. The details, below, are for bees that were collected in 2017 and 2018 and identified by Sarah Kornbluth (2017) or Gabe Foote (2018).
We collected five species of bee in the genus Megachile:
Megachile
rotundata (2 females and 1 male)
Megachile
angelarum (8 females and 5 males)
Megachile
perihirta (1 female)
Megachile
fidelis (3 females)
Megachile
centuncularis (1 female)
Worldwide, Megachile bees are extremely diverse: an estimated 1,400 species of Megachile bees can be found, globally and an estimated 140 species of Megachile can be found in the United States. These bees are in the Family Megachilidae, which includes the leafcutting (e.g. Megachile species), mason (e.g .Osmia species), and wool carder bees (e.g. Anthidium species). In the family Megachilidae, females carry pollen on their abdomen.
In this post, I wanted to cover Megachile fidelis, Megachile perihirta, and Megachile angelarum.
Bee Species
Origin
Diet
Sociality
Nesting
Megachile angelarum
Native
Generalist (Prefers Lavandula, Perovskia, Vitex)
Solitary
Cavity
Megachile perihirta
Native
Generalist
Solitary
Soil
Megachile fidelis
Native
Generalist (Prefers Asters)
Solitary
Cavity
Megachile angelarum was the most common bee in this genus that we collected from Portland area gardens.
Megachile angelarum female.
Diet: Although this species has been collected from a broad array of floral hosts (see list from Discover Life), Frankie et al. (2014) note that this species prefers lavenders (Lavendula), Russian sage (Perovskia), and chaste tree (Vitex).
Sociality: This species is solitary, which means that each individual female builds her own nest, collects nectar and pollen to provision her young, and lays her own eggs. In bees with advanced social structures, such as honey bees, the workers collect nectar and pollen to feed the young, and the queen lays the eggs. Solitary bees die soon after they build their nest, load nest cells with pollen and nectar, lay their eggs, and seal the nest cell shut. Many solitary bees may nest in close proximity to each other. Thus, solitary bee doesn’t mean loner bee; it means that the female does all of the work on her own, without cooperation or collaboration from other bees in her species.
Nesting: Megachile angelarum nests in cavities. Rather than cutting leaves, females collect resins and gums to partition nest cells. Since this bee does not cut leaves, it lacks teeth on its mandibles, unlike other bees in the genus. The bee has been found in drilled pine wood (10cm deep holes, 0.5 cm in diameter; Dicks et al. 2010). Other studies have found this species in nest blocks with a 3/16th hole size (Galasetti 2017).
Appearance: Like many bees in this genus, it is a robust-sized bee, with females typically spanning 10-11 mm in length and males a bit smaller, at 8-9 mm in length. The lack of teeth and cutting edges on the mandibles can be helpful for identification.
Megachile angelarum. The mandibles are a bit hard to see, by they are in the lower portion of the face. Note that there are no teeth, or serrated edges on the mandibles, which is a characteristic of this bee.
Notes: Across 2017-2018, we collected this bee from seven different Portland area gardens, or nearly 1/3 of our sampled gardens. Megachile angelarum is likely parasitized by another bee, Stelis laticincta. Stelis laticincta is a social parasite, or cleptoparasite of other bees. What this means is that Stelis laticincta invades the nest of another bee, and lay their own eggs, just as cuckoo birds do with other birds. Once the Stelis laticincta eggs hatch, the larvae kill the Megachile angelarum larvae, and eat the pollen and nectar provisions that have been provided by the Megachile angelarum mother.
We collected a single Stelis laticincta in 2017-2018, and it came from a garden where we collected four Megachile angelarum specimens. Having a healthy Megachile angelarum population increases your chances of having more bee species, by supporting cleptoparasites, such as Stelis laticincta.
Megachile perihirta is commonly known as the Western leafcutter bee.
Diet: This bee is a generalist, and will collect nectar and pollen from many different types of flowering plants.
Sociality: Solitary (see notes for M. angelarum).
Nesting: Unlike many Megachile bees, this species does not nest in cavities, but instead digs shallow nests in the soil (Frankie et al. 2014, page 102). I had thought that all bees in the genus Megachile were cavity nesters. (Actually, I thought that all bees in the family Megachilidae were cavity nesters). But, Eickworth et al. (1981) report that soil excavation was widespread in the family Megachilidae and in the genus Megachile.
Appearance: This was the largest Megachile species we collected. Females typically spanning 13-14 mm in length and males span 12-13 mm in length.
Megachile perihirta female.
I am soooooo sad that we didn’t collect a male of this species! The males have enlarged forelegs, covered with hairs (photos of the males can be found here and here), which the MALES USE TO COVER THE FEMALES EYES DURING MATING!!!! Biologists suggest that this helps to keep females calm and receptive, during mating (Frankie et al. 2014, page 103).
Notes: We only collected a single specimen of this bee. It came from our smallest garden (1,800 square feet in size), in an industrial area of Northeast Portland. And seriously: how cool is it to have a bee species where the mating ritual includes the male covering the females eyes with his super-hairy forearms!!!??
Megachile fidelis
Diet: Frankie et al. (2014) note that this species seems to prefer plants in the Asteraceae, including Aster, Erigeron, Rudbekia, Cosmos, and Helenium). Hurd et al. (1980) note that this species is commonly collected from sunflowers (Helianthus).
Sociality: Solitary (see notes for M. angelarum).
Nesting: This is a cavity nesting bee that tends to occupy larger holes (0.65 to 0.80 cm in diameter (Barthell et al. 1998). Unlike Megachile angelarum, which does not cut leaves or petals to line their nest cells, UC Davis has a great photo of a female Megachile fidelis carrying a piece of Clarkia petal. In his native bee research, Aaron Anderson would regularly find bees cutting neat discs from Clarkia flowers. I wonder, now, if collecting petal discs from Clarkia flowers is characteristic of M. fidelis.
Appearance: This species is another robust-sized bee. Females typically spanning 11-13 mm in length and males span 10-12 mm in length.
Megachile fidelis female.
Once again, I am beyond bummed that we didn’t collect a male of this species! Males of this species also have enlarged forelegs covered with long hairs, although not as pronounced as in male M. perihirta. Once again, biologists suspect that the males use their hairy forearms to cover the females eyes during mating (Frankie et al. 2014, page 103).
Notes: We collected one specimen from a 0.2 acre, flower-filled garden that is adjacent to a golf course in Canby. The other two specimens were collected from a 0.1 acre, flower-filled garden in Northeast Portland.
Although I have been studying garden bees for the past three
years, I was never focused on honey bees. From a biodiversity point of view,
they are not very interesting to me. They are non-native and abundant. In fact,
honey bees were the most abundant bee species that we collected in
Portland-area gardens (332 individuals collected), even though we took great
care not to collect more than one individual per visit, when hand-collecting.
Some of the 300+ individual honey bees that we collected from Portland area gardens, even though we took great care to not hand collect more than a single individual honey bee per garden, per site visit.
Honey bees, which hail from Europe, are only one of 20,000 bee species, worldwide. In North America, there are 4,000 species of bee. In Oregon, we have between 400-500 species of bee. From Portland area gardens, we have documented 86 species of bee (with our 2019 bees still awaiting identification).
Unlike some native bees, honey bees are not at risk of extinction. Compare this to bumblebees. We found 17 species of bumblebee in Portland gardens, two of which (12%) are at risk of endangerment or extinction, due to declining populations: Bombus fervidus and Bombus caliginosus. Across North America, more than 25% of bumblebee species are thought to be at risk of extinction.
Frontal view of Bombus fervidus, a threatened bumblebee species that can be found in Portland area gardens.
Dorsal view of Bombus fervidus, a threatened bumblebee species that can be found in Portland area gardens.
By focusing ‘save the bee’ campaigns on honey bees, we may
be neglecting the bee species that really need our help. In fact, researchers
have started to call out organizations and advertising campaigns that promote
feel good stories about honey bee conservation as a form of ‘bee washing’. You
can visit www.bee-washing.com to learn
more about companies that promote their product or organization as being
bee-friendly, in a less than genuine way.
Researchers have documented at least seven different ways that honey bees may harm native bee species (summarized in Cane and Tepedino, 2016):
Honey bees monopolize and deplete nectar and pollen from local plant communities, which can reduce native bee reproduction.
By depleting local plant resources, native bee females have to devote more time and energy to fly and find new resources, which also reduces native bee reproduction.
Unlike honey bees, most bees are solitary, which means that they do not live in colonies and they do not have a queen. Solitary females who have access to fewer floral resources produce fewer daughters and more sons. Since female bees are needed to maintain a population, this skewed sex ratio can slow population growth and recovery in native bees.
When females collect less nectar and pollen, they have less food to feed their young. These bees grow up to be smaller, and are more likely to die over winter, compared to well-fed bees.
The longer a solitary bee mom is away from her nest, the higher risk that parasites and predators will attack her unguarded young.
Honey bees can physically block native, solitary bees from preferred pollen hosts.
Honey bees have many diseases. Some honey bee viruses have been found in native bee communities. Researchers think flowers that are visited by both native bees and honey bees are analogous to an elementary school water fountain: a place where repeat visitors can pick up a pathogen.
Please note that I am not suggesting that you extinguish honey bees from your garden. What I am asking, instead, is that you take the time to learn about and to notice some of the other 80+ species of bee that you might find in your garden. My group is creating a ‘Bees of Portland Gardens’ guide that we hope can help you in this journey. In the meantime, there are some great guides that are currently available. One is Wilson and Carrill’s ‘The Bees in Your Backyard: a guide to North America’s bees’. This book is available at Powell’s City of Books, as well as on Amazon. The second is August Jackson’s ‘The Bees of the Willamette Valley: a comprehensive guide to genera’. This free guide can be found online.
The first step to
saving something you love is to be able to recognize it and to call it by name.
References
Cane and Tepedino. 2016. Gauging the effect of
honey bee pollen collection on native bee communities. Conservation Letters10:
205-210.
Jackson. 2019. The Bees of the Willamette
Valley: A Comprehensive Guide to Genera. Self-Published, Online: https://tinyurl.com/y4qfssrl.
Wilson and Carrill. 2016. Bees in Your Backyard:
A Guide to North America’s Bees. Princeton University Press.
A few weeks ago, I tweeted about the difference that the Alda Center for Communicating Science has made in my teaching. To my sincere surprise and delight, Mr. Alda, himself, quoted my tweet, in one of his own. It made my day.
And today, after my last lecture of the term, the lab instructor sent me this note:
“I have students here putting in extra time (!!) on their [insect] collections, and they’re talking about how much they loved your class, and the applause you got at the end of class today. One of them is saying how it’s about time she had a class that was 100% relevant to Ag. I’m so happy for you, Gail, . . . I wish you could hear their conversation 🙂 “
To fully appreciate how much these comments mean to me, you have to understand how much of a struggle it is for me to teach. I score very high on the introversion scale. I hate the idea of teaching as performance (why do I have to entertain them?). I’m a stickler for academic rigor. My classes have a reputation for being difficult. And, I teach a required course that all majors must take (whether they are interested in entomology, or not), that is scheduled for M/W/F at 8am. All of these things, added together, make me a fairly unpopular teacher.
The Alda immersion program did all of these things, and more. The premise of the workshop is that ‘Connection is the Key’ to effective science communication. The workshop instructors (including Alan Alda) use improv exercises in small groups and with partners to teach storytelling, message design, and how to really listen to, empathize with, and engage with your audience. Key messages were embraced over the recitation of hypotheses and theory. A heavy focus was put on connecting with your audience, so that even if they were not ready to listen to you in that moment of time, you might be able engage them at some point in the future.
There were two turning points to the workshop, at least for me.
The first was when we partnered up with someone to explain our science in 2 minutes, then 1 minute, then 30 seconds. Between each round, our partner gave us feedback on how to refine our message. When we came back together as a group, each person had to explain their partner’s science, rather than their own. In almost all cases, folks did better explaining someone else’s science ~ because we didn’t get bogged down in details. This really helped me to limit how much information I present in my classes. Instead of teaching *everything a person should possibly know* about a topic, I focus on key points, and how those points relate to students’ lives.
The second was when Mr. Alda demonstrated how he would discuss science with someone who believes the earth is flat. There was such a genuine kindness in the ‘conversation’ he had with the flat-earther ~ acknowledging their experience (the earth looks flat to them) while adhering to the science that demonstrates that earth is a sphere. It made me realize that I had become so accustomed to being right and defending my interpretation of science, that I rarely listened to others who disagreed with me. I was too busy formulating my retort, to truly listen to and understand their perspective.
This revelation was coupled with an exercise that was called ‘My Dear Friend’. In this exercise, you spend a few minutes ranting at your partner about something that drives you crazy. I ranted about the state of higher education, today. Your partner then has to share your rant with the group, by saying something like ‘this is my dear friend, Gail, and she cares passionately about the education that her students receive.’ I use this exercise, nearly every week. In fact, when I returned to the office from the workshop, there was an anonymous letter in my mailbox that was signed by ‘a disgruntled Master Gardener’. I reread that letter, and instead of feeling attacked, I could see how much the person loved this program that I help to coordinate, and how they wanted to share their passion for the program.
In terms of my teaching, the Alda workshop helped me to slow down, focus on key messages, and truly care for my students. This term, I am 6 classes behind where I would normally be. But, I think my students learned and retained more than they have in the past.
I stopped worrying about students who missed class, or who might try to cheat. Instead, I designed my class so that students who had to miss class (for whatever reason) had built in buffers that could help them absorb or make up lost points. These included things like dropping your two lowest quizzes, or earning extra credit points for lecture participation. I built an array of assessments into the class, including TopHat clickers from mobile devices, and adding ample short answer and essay sections to my exams. These things both made it more difficult to cheat, but also offered students with different learning styles different chances to do well.
I started bringing in breakfast on Fridays. I did this because Thursday is the traditional ‘party night’ on a university campus. In the past, my 8am Friday classes often had 15 or fewer people in attendance. (There are 50 enrolled in the course). I wanted to bring a small breakfast to say ‘thank you for showing up’. Over the course of the term, more and more students started to show up, and not just on Fridays. They went out of their way to thank me. Some told me that they were hungry, and that the small meal made a big difference to their day. Being a Filipina who loves to feed people, by nature, that’s all I needed.
There were a few other things, as well . . . students who shared some difficulty that they were going through that made it difficult for them to do well in class. Instead of my past approach of ‘not my problem’, I tried to help where I could.
Mostly, when I stopped feeling like I was there to serve as some sort of academic guardian . . . keeping all but the most-worthy students out . . . that’s when everyone (including myself) became invested in learning.
When I said goodbye to my students today, I heard the applause . . . but I was so confused. Was someone watching YouTube videos, in the back? It honestly makes me tear up to think that it might have been because they loved the learning environment that we built, together.
Aaron Anderson is repeating his original survey on native plants and pollinators. This time, he is trying to understand how knowledge of a plant’s ecological function may alter impressions of native plants.
The survey takes about 25-30 minutes to complete. Folks who have taken the survey thus far have commented on how much they learned from taking the time to answer the questions.
If your time and interest allows, we would be extremely grateful if you could take the time to respond to this survey. The direct link to the survey is:
With all due respect to Beyonce, insects were recognized as ‘The Little Things that Run the World‘ by entomologist E.O. Wilson, decades before Beyonce’s 2011 hit song. As Wilson wrote in his iconic perspective piece:
The truth is that we need invertebrates but they don’t need us. If human beings were to disappear tomorrow, the world would go on with little change.
In fact, Wilson noted, the Earth ‘would set about healing itself‘. But if invertebrates were to disappear, Wilson predicts that ‘I doubt the human species could last more than a few months‘.
California Tortoiseshell, taken in a Portland-area garden on August 22, 2017.
These articles covered recent science papers that have caused a lot of concern, and generated a lot of attention. In the ENT 518 class that I am teaching this term (Current Topics in Entomology), our class spent time dissecting and discussing the science papers, as well as popular press coverage of each study.
The first paper, published in 2017 by Hallman and colleagues, documented a 76% decline in insect biomass over a time period spanning nearly three decades. In the peak summer season, the decline was even larger (82%). These researchers had been sampling protected areas in Germany using Malaise traps. This group is working to identify the insects that they collect ~ but, because it takes so much time and specialized expertise to identify most insects to species ~ they also took data on the collective weight of the insects that they collected. This is how they were able to show a 76% decline in insect biomass, between 1989 and 2016.
Mardon Skipper taken in a Portland-area garden on August 22, 2017.
What caused this massive decline in insect biomass? To address this question, They constructed a series of models to try and identify what factors might explain this precipitous drop in insect biomass (which is being used a proxy for insect abundance). They did not find evidence (from their mathematical models) that climate factors (e.g. temperature, precipitation, wind speed), habitat factors (e.g. site conditions, plant species), or habitat factors (e.g. amount of forest, grassland, water) were responsible for insect declines. Because they did not find evidence that climate change, landscape conversions, or habitat changes reduced insect biomass, they concluded that factors which they did not measure were responsible for insect declines. Specifically, they hypothesize that agricultural intensification (pesticide use, year round tillage, increased use of fertilizers) was a plausible cause.
Students taking the ENT 518 class were mostly convinced that the researchers had documented a large and significant decrease in insect biomass over the time period of the study. Students agreed that the loss of biomass reflects a loss in insect abundance, and probably reflects a loss of insect diversity. Students were more reserved in their assessment of the authors’ suggestion that agricultural intensification was the cause of the decline. Although they agreed that it is a plausible explanation, they wanted to see data to address this hypothesis, rather than having the authors arrive at this conclusion because they eliminated other potential causes of insect decline (e.g. climate change, landscape conversion, habitat change).
Western Tiger Swallowtail, taken in a Portland-area garden on July 27, 2017.
The second paper, published in 2019 by Sanchez-Bayo and Wyckhuys, was a review of other papers that studied insect declines. The authors searched science databases for the words ‘insect’ AND ‘decline’ AND ‘survey’, and then reviewed the hundreds of papers (653!) that they found to limit their survey to 73 long-term studies that took place for 10 years of more. The authors then summarize the details of each study, according to major insect groups (e.g. butterflies, bees, beetles, flies). Ultimately, they report that 41% of all insects are in decline, and that across all insect species, the annual rate of decline is 1% per year, and the annual rate of insect extinction is 1% per year. Like the Hallman et al. paper, Sanchez-Bayo and Wyckhuys suggest that agriculture is to blame:
‘Overall, the systemic, widespread and often superfluous use of pesticides in agricultural and pasture land over the past 60 years has negatively impacted most organisms, from insects to birds to bats . . ‘.
The students in ENT 518 honed in on the fact that the authors searched for the words ‘insect’ AND ‘decline’. Accordingly, there was a level of bias in their search procedures. Students seemed convinced that many insect groups are in decline, but were less willing to agree that the overall level of decline, rate of decline, and rate of extinction reported by the authors were accurate estimates. In addition, although students agree that pesticide use is likely to blame for insect declines, they would have been more convinced, if there were better data tying the two together.
Students then discussed how the science papers were translated into a narrative for the NY Times and Atlantic articles. We talked about the elements of a story, and how as scientists, we don’t worry about setting the scene, developing characters, or of conflict in a plot. But, many of us are also science communicators via our work in Extension or through other outreach efforts. If we can paint a picture that people can relate to ~ if we can get them to notice and to share their experience with noticing fewer insects in their yard or their town ~ will they care more about insect conservation?
One of the major reasons that we do the work that we do in the Garden Ecology Lab is because we believe that how we manage our gardens can truly make a difference to insect conservation. If we can take better notice of those ‘little things that run the world’ and share these experiences with our friends and family . . . will that make a difference? I believe that it will. In fact, it is the reason that I come to work, each and every day, excited to learn more about how we can make this world a better place through gardening.
If you love bees, and you have not yet subscribed to PolliNation, you’re missing out! OSU Professor and PolliNation podcast host, Andony Melathopolous, does a wonderful job assembling a diverse array of guests to talk all things pollinator.
Aaron Anderson recently joined Andony on episode 94 of thePolliNation podcast, to talk about his research on native plants, different insect groups, and gardeners.
Aaron talks about the 100+ study plots that he manages (two of which you can see, below), as well as which plants were most attractive to bees (such as the California poppy, on the left) versus those that were more attractive to gardeners (such as the Oregon iris, on the right).
In other news, our lab group has been very busy. All of the 2017 and 2018 bees from our garden pollinator study have been identified to species (unless they are truly recalcitrant to being ID’d to the level of species). Gabe has been working with Lincoln Best to identify the 2018 bees. The 2017 were verified by Sara Kornbluth, and provided a great reference collection against which we could compare the 2018 bees. Gabe has been a short-time member of our lab group, but his expertise has been a huge benefit to our program. He leaves us at the end of April to start field work in the College of Forestry. After that, he heads to UC Davis to do his Ph.D.
This summer will also be Aaron’s final year of field work at the North Willamette Research and Extension Center. This final year will help to resolve some of the differences we saw between his 2017 and 2018 data set.
After two years of amazing assistance in the lab and in the field, Isabella has started an independent research project on campus. She has planted some of Aaron’s study plants in gardens on campus, and is looking to see if bee visitation and bee communities markedly change, when you take them out of single-species plantings (like Aaron is studying) and put them into a garden setting.
Mykl is working to write up his urban soils data for publication. We are also hoping to do a side publication, comparing the soil types that we’re finding in home gardens, and seeing how they align with the types of soils that nesting bees prefer.
Lauren is writing up her capstone paper, and is preparing to defend this term. She surveyed gardeners to try to understand how well they can identify bees from other insects, and how well they knew bee-friendly plants from those that offered few or no nectar/pollen resources to bees.
Signe is taking the data that we are collecting, and working our findings into the online Master Gardener course. The best part of our work is being able to see gardeners put some of our research-based recommendations into action. Signe plays a huge role in translating our work for the general public.
Angelee is a relatively new member of the lab. She comes to us from the OSU STEM Leaders program. She’s learning lab protocols and lending a hand on just about every project. She has been a joy to work with.
Lucas has moved on from the lab, but still helps us with remote data-basing work, on occasion. He was a joy to work with, and I feel lucky that he stuck with us for a few years.
This entry is from Angelee Calder, and undergraduate Agricultural Science student at Oregon State University. It highlights a bumblebee that can be found in Oregon gardens, but that is currently listed as ‘Vulnerable’ to endangered species status, due to documented population declines (Hatfield et al. 2015).
Dorsal view, Bombus fervidus. This bumblebee was collected from a Portland area garden in August 2018. Photo Credit: Angelee Calder and Isabella Messer
Anterior view, Bombus fervidus. This bumblebee was collected from a Portland area garden in August 2018. Photo Credit: Angelee Calder and Isabella Messer
When we think of bees, we usually conjure up the image of a cute fuzzy black and yellow puff of an insect. Bombus fervidus, which is also known as the Golden Northern Bumble Bee,looks just like that cute bee stereotype. This bumble bee has a black face, yellow body, and single black band across its body near its wings (Discover Life 2019). Although Bombus ferviduscan be found across most of the whole United States, studies have shown that their population numbers are declining (Colla and Packer 2008). This bee is attracted to clover, which is one reason to tolerate (or even embrace) clovers in residential lawns.
We spent 120 hours hand collecting bees from 24 Portland area gardens in 2017 and 2018. In addition, across these two years we set out water pan traps to collect bees for an additional 3,450 hours of passive collection. In all this time, we only collected two Bombus fervidus. Both were collected from the same yard in August 2018. This yard is our largest garden, and it sits adjacent to Forest Park. It could be that this species, known to be in decline, does best with larger patches of habitat, that are close to a natural area.
The Northern Golden Bumble Bee is in the running for cutest bee, so make sure to take a look while he is out foraging. The peak viewing times to catch a glimpse of these cuties May to October (BugGuide.Net 2019).
References
Colla and Packer. 2008. Evidence for decline in eastern North American bumblebees (Hymenoptera: Apidae), with a special focus on Bombus affinis Cresson. Biodiversity and Conservation 17: 1379. https://doi.org/10.1007/s10531-008-9340-5.
Isabella Messer has been a member of the Garden Ecology Lab for more than two years, where she primarily assists with the garden pollinators study, but will is also developing her own research project. Her independent research project will look at bee visitation to some of the plants we are studying in controlled research trials, when these same plants are in a mixed garden setting. Controlled research trials are important, because they let us document the attractiveness of plants to bees, in a setting where study plants are not competing with other plants for pollinators. Controlled research trials are also valuable, because they let researchers have better control over environmental conditions, such as irrigation. Isabella is going to see whether and how bee visits on plants in a garden context is different than what Aaron is documenting in his controlled research trials. This will be one of the first, if not the first time, that we will have direct and contemporaneous measures of bee visits on focal plants in each situation: in a research field, and in a garden.
In addition to her work in the lab, Isabella is also a member of the ‘Research Retinue’: a group of Oregon State University undergraduates, who review and discuss papers on the PolliNation Podcast.
In this episode, the retinue discusses two papers that look at the impact of a common herbicide (glyphosate) on bees, via indirect impacts of glyphosate on the microbiome (bacterial community) that can be found in honey bee guts.
Aaron’s webinar on his Ph.D. research has been posted on YouTube.
He highlights some really interesting results from his 2017 and 2018 field seasons, including recommendations for what to plant, if you are interested in attracting native bees to your garden. I’ve asked him to write a blog post, summarizing the results to readers.
