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‘.
Insects, the most abundant and numerous of all invertebrate animals, play a particularly important role in our world and in our life. Not counting the enormous contributions of non-native honey bees, which annually help to bring $235 and $577 billion dollar worth of food to the global market, native insects contribute $71 billion dollars (inflation adjusted to 2019) worth of ecological services to our economy and to our society.
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.
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).
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.
For the garden bee project, we have >50 verified species of bees collected from Portland-area gardens, with a few more at the morpho-species level. This summer will be our final year of collections.
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 fall, Jen will be joining our group as a new M.S. student. We will also be close to launching the first course in the online Urban Agriculture certificate program, which is being spear-headed by Mykl. We should also be pushing out a few more papers from our garden work, to join our first concept paper on the value of urban garden bees to urban and peri-urban agriculture.
The first distinct connection to food I remember was in the late 90s while living in İzmir, Turkey. We had a large mulberry tree in our yard which bore delicious fruit. I also remember the bazaar in the Buca province. Cart after cart of people selling mounds of all manner of produce. After leaving Turkey, and for maybe half of my childhood summers, I lived on the farm of my paternal grandparents’ in Worland, Wyoming. I saw many aspects of high, dry farming of row crops: sugar beets, alfalfa, barley, and dent corn. I could only catch fleeting glimpses into the life of my grandfather, a commodity farmer. But in my recent years I’ve been openly told that these American farmers vehemently hoped their children were “too smart to get into farming.” Their wish came true. Of four children and nine grandchildren, I’m the only one in agriculture.
I turned on to agriculture when a friend and I built a 400 square-foot poly-tunnel in our backyard in Colorado. We didn’t know anything more than that we wanted to grow our own food. I remember feeling so incredibly accomplished, fulfilled, and validated picking personal salads straight into dinner bowls. I took that inspiration to fuel my travel to the Pacific Northwest, a place I knew I could immerse myself in the world of tending plants. I pushed every aspect of my network to get more involved in farming and to gain space to garden. I’ve worked on three organic urban farms since moving to Oregon. I went back to school and retrained from political science to agricultural science. I continued my education with a graduate project which firmly oriented my interests to the world of urban agriculture.
I am now an instructor of urban agriculture here at Oregon State University. My current duties are to develop new online courses to train and empower new urban growers to produce food within the confines of their modern environment. This work is challenging, as urban agriculture suffers from a distinct lack of focused research. One of the most relevant discoveries from my graduate research project is that nearly all advice extended to urban growers is simply copied from traditional agriculture. Even if suggestions are altered with respect to the scale and local environment of urban growers, the research supporting these suggestions is still wholly based upon traditional agricultural methods of food production. I am developing my courses with this mismatch in mind. I have changed my approach from seeking to broadly support food production and instead specifically analyze and adapt traditional recommendations to work in an urban environment.
I use scientific research to inform my course development on many levels. At the macro-level, articles like one by Oberholtzer, Dimitri, and Pressman (2014) have reported that most farmers, and new farmers especially, struggle with complications in managing the farm’s business much more than the challenge of growing their crops. I used these findings to inform the outline of a new course that I am developing: Introduction to Urban Agriculture. Rather than spending time covering the how or why of plant growth in much detail, I’ve instead focused on how urban growers can adapt agricultural principles to their unique environment. I strive to keep students aware of how these factors should influence their management activities and always keep the concept of ‘value’ in their mind. On a more micro-level, I have built the lectures regarding soil and plant growth with adaptations of my own previous graduate research.
My method of teaching is heavily influenced by a new wave of teaching research which is well represented by James Lang’s book: Small Teaching. Broadly, this approach suggests frequent review of material as well as a more piecemeal and cyclical approach to teaching topics rather than large chunks of lecture punctuated by intermittent exams. Further, I refuse to accept that an online classroom is limiting. Modern students are demanding more than just lectures laid over powerpoint slides. I am exploring numerous avenues to increase engagement and foster social connection, all facilitated by digital platforms. I expect my courses to provide foundational pillars of knowledge for new urban growers as they pursue OSU’s new and entirely online certificate in urban agriculture. I hope to see every student embark on their own path to grow food within their urban environments. I look forward to reports of former pupils starting and operating successful urban farming businesses.
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).
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 fervidus can 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).
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.
BugGuide.Net. 2019 “Species Bombus fervidus – Golden Northern Bumble Bee”, https://bugguide.net/node/view/23135. Accessed February 27, 2019.
Discover Life. 2019. “Bombus fervidus“, https://www.discoverlife.org/mp/20q. Accessed February 27, 2019.
Hatfield, R., Jepsen, S., Thorp, R., Richardson, L., Colla, S. & Foltz Jordan, S.2015. Bombus fervidus. The IUCN Red List of Threatened Species 2015: e.T21215132A21215225.http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T21215132A21215225.en. Accessed February 27, 2019.
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.
The paper that they discuss is linked, below:
- Motta, V. S. E, Raymann, K, and Moran, N. A. (2018) Glyphosate perturbs the gut microbiota of honey bees. Proceedings of the National Academy of Sciences (PNAS), (41): 10305-10310
It’s been a while since I’ve posted a field update about my native plant – pollinator study, so this post will be a recap of the entire 2018 field season! Sampling this year was successful, though it was a much shorter bloom season for almost all the flowers species, perhaps due to a combination of the heat, low rainfall, and lack of supplemental irrigation. I performed some summary statistics on the data, and there are some intriguing results from this year.
Below is a summary of some of the highlights:
- Only two (Gilia capitata and Nepeta cataria) flowers made it into the top-five most attractive in 2017 and 2018. The full results can be visualized in the two histograms below.
- Three of the non-native garden species were found in the top five in 2018 (though I noted this visitation seemed strongly driven by honey bees).
2017 overall bee abundance by plant species:
2018 overall bee abundance by plant species:
Because of this, I removed honey bees from the dataset and recreated the graphs.
- The 2017 visitation data is largely unchanged (though Nepeta cataria is less attractive, and Eschscholzia californica jumps into the top-five).
- When only native bees are considered, the top-five most visited 2018 plants are almost completely different. Eschscholzia californica, Aster subspicatus, and Phacelia heterophylla are the three most attractive flowers.
- It seems like the native wildflowers are being visited more frequently by native bees.
2017 native bee abundance by plant species:
2018 native bee abundance by plant species:
I also take vacuum samples from each plot so that we can identify pollinators (and other insects) to species. I’m excited that my 2017 and 2018 bees have been identified by taxonomist Lincoln Best!
Across those two years, we collected 36 bee species (from 540 samples, which doesn’t include all the honey bee individuals). You might ask – is this many bees, or only a few? Simply put – we don’t know! Without knowing how many bee species are found at our site at NWREC, its hard to tell what this number means. However, I was excited to find that we collected two bumblebees that are on the IUCN Red List, Bombus fervidus and Bombus calignosus.
Below are a two pollinator interaction matrices to visualize these data, but I should note that these are very preliminary – they are not scaled by number of sampling events but are still a neat way to visualize interactions and richness data. (Darker squares represent higher abundance; a white square means no bees were collected off that flower).
Bumblebee Richness and Abundance:
Other Native Bee Diversity and Abundance:
Its obvious from looking at these data that the answer to the question “which plants attract the most pollinators?” isn’t simple! Are we interested in certain suites of bee species – honey bees, or bumblebees? Are we interested in high overall abundance, or high species richness? Some species attract many individuals but few species, while other plants attract a higher species richness but fewer overall individual bees. Additionally, there are also seasonal changes in bee populations to consider, as well as seasonal changes in flower phenology and floral display.
Luckily we’re going to have a 2019 field season, which will help account for this temporal variation and allow us to acquire data for species that didn’t flower in one or both of the previous years.
Original “Plant of the Week: Douglas Aster” post available here: http://blogs.oregonstate.edu/gardenecologylab/2017/11/07/plant-week-doulgas-aster/
Last November I took a look at a Pacific Northwest favorite, the Douglas aster (Symphyotrichum subspicatum (1)). What I didn’t know then was just how popular this species would be with the bees we had been sampling in the field. It turns out that while surveyed gardeners ranked Douglas aster 14 out of 27 in terms of attractiveness, based on the 2017 data it boasted the third highest number of bees (2). This means that it is the most attractive native perennial species for bees that we sampled, and the 2018 data shows this as well (3). Based on the gardeners’ ranking, however, which placed it in the bottom 50% of all the species we sampled, it also looks as though the Douglas aster is in need of some public relations help.
It is my personal belief that it isn’t just the showiness of the blooms or the potential benefits to X, Y and Z that brings plants into our gardens, but rather the stories we tell about them. Familiarity after all is more than just recognition; it is also marked by appreciation and understanding. One of the stories we can tell through our work in the Garden Ecology Lab about Douglas aster is of its relationship with our native bees. As gardeners we are uniquely positioned to both benefit from and to be of service to these insects.
Here are some of their “faces”:
The most common genus of bees collected from Douglas aster in the field, Melissodes are true summer and fall flyers, easily recognizable by their long antennae. These bees are solitary ground nesters, although they have been observed forming nesting aggregations in the soil (4). While we collected potentially five species of Melissodes in total, one species in particular, Melissodes microsticta, was especially common. Many Melissodes species are generalists, but can usually be found visiting members of the Asteraceae family (such as sunflowers and our Doulgas aster) because of their late season blooms.
The second most commonly collected visitor of Douglas aster, the yellow-faced bumblebee is really a remarkable native pollinator. While many native bees are considered solitary, bumble bees are social insects, with a queen and workers (4). Like non-native honeybees, they have been investigated for their potential as commercial pollinators, being used in greenhouse production (5). Isabella Messer wrote a post for the “Pollinator of the Week” series highlighting these ubiquitous bees that can be found here: http://blogs.oregonstate.edu/gardenecologylab/2017/08/29/pollinator-week-yellow-faced-bumble-bee/
Ligated Furrow Bee
The third most commonly collected visitor of Douglas aster is the ligated furrow bee. Found throughout North America, Halictus ligatus is special amongst native pollinators (like the yellow-faced bumblebee) for its social nature (4). Sociality is rare amongst native bees, as it is in nature in general, but amongst the Halictus the situation is even more unique. This is because, unlike other social species, Halictus have been seen to switch back and forth between solitary and social behaviors over time as environmental conditions differ (4). Isabella wrote a post about these bees a while back for the “Pollinator of the Week” series that can be read here: http://blogs.oregonstate.edu/gardenecologylab/2018/04/30/pollinator-week-mining-bee/
Virescent Green Metallic Bee
The fourth most commonly collected visitor of the Douglas aster is none other than my personal favorite, the virescent green metallic bee. These stunning bees are communal soil nesters and are members of the Halictidae family, cousins of the ligated furrow bee introduced above (4). I wrote a post about them for the “Pollinator of the Week” series last November that can be found here: http://blogs.oregonstate.edu/gardenecologylab/2017/11/13/pollinator-week-virescent-green-metallic-bee/
In addition to these bees, we also collected striped-sweat bees (Agapostemon texanus/angelicus), brown-winged furrow bees (Halictus farinosus), metallic sweat bees (Lasioglossum sp.), and common little leaf-cutter bees (Megachile brevis). We also collected with a number of long-horned bees (Melissodes) that have yet to be identified to species.
Walking the streets of Portland and seeing Douglas aster’s purple flowers still in bloom this late in October brings a smile to my face because it tells me that people are indeed planting this species. If only for its benefit to wildlife and pollinators in particular, that is still good news. As you may be able to tell from the information given above, we are still learning about these bee species while we are simultaneously working to save them — not just for future generations but for ourselves as well. Hopefully, by putting a “face” to the bees that visit and depend on these plants and our gardens, the bond that links us to them can be strengthened and our preference for them in our landscape enhanced.
- Geraldine A. Allen 2012, Symphyotrichum subspicatum, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=88843, accessed on October 30, 2018.
- Langellotto, G. (2018, September 12). Do Gardeners Like the Same Flowers as Bees? [Blog post]. Retrieved from http://blogs.oregonstate.edu/gardenecologylab/2018/09/12/do-gardeners-like-the-same-flowers-as-bees/
- Anderson, A. (n.d.). First Look: Research Into Native Plants in the PNW Garden. Webinar. Retrieved from http://blogs.oregonstate.edu/gardenecologylab/2018/10/23/webinar-on-willamette-valley-native-plants-and-pollinators/
- Wilson, J. S., & Messinger Carril, O. (2016). The Bees In Your Backyard. Princeton, NJ: Princeton University Press.
- Dogterom, M. H., Matteoni, J. A., & Plowright, R. C. (1998). Pollination of Greenhouse Tomatoes by the North American Bombus vosnesenskii. Journal of Economic Entomology, 91(1), 71-75. doi:https://doi.org/10.1093/jee/91.1.71
- Oregon Department of Agriculture: Bee Pollinators of Oregon. (2016). Retrieved October 30, 2018, from https://odabeeguide.weebly.com
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.
In case you missed the webinar on our garden bee research, I’ve embedded the video, below. The entire webinar is about an hour.
And, make sure to mark your calendars for Monday, October 22nd at 11am PST. Aaron Anderson will be presenting a FIRST LOOK webinar on his research on native plant-pollinator associations. Visit the hypertexted link, above, to register for this FREE webinar.
Aaron was sharing some of his latest data with me, just this past week. His data, collected at replicated field plots in Aurora, Oregon, echoes what we’ve seen in home garden sites around Oregon: for native bees, Douglas Aster was a top performer.
Lauren Bennett, a Master’s student at OSU, is doing her capstone project on pollinators She has a short survey (10-15 minutes) on pollinators and pollinator plants.
If you could spare a few moments of your time, we would appreciate your participation in this study. More information this study can be accessed, by following the link, below.
FYI ~ this study was deemed ‘quality improvement / assessment’ and not ‘scholarly and journalistic’ by the OSU IRB. Thus, we do not need or have IRB oversight for this study.