The Ethics, Politics, and Science of Lethal Insect Sampling

Posted on November 7, 2024 by Gail Langellotto

A version of this blog post was written for the Hardy Plant Society of Oregon (HPSO) Quarterly Magazine, and was greatly improved by comments and feedback from the HPSO team of editors.

I had been to my mom’s hometown of Bagamanoc many times, but never before as a budding entomologist. In 1993, I packed my bags with the many tools used to collect and curate insects: glassine envelopes to store and sort butterflies, insect pins and boxes, a pinning block, and nets. Once on the ground in this rural region of the tropics, I set out to catch and kill new specimens for my personal insect collection. My prized find was a large birdwing butterfly, with black and red markings and wingspan of more than 6 inches: Atrophaneura semperi. I nearly vibrated with excitement as I caught her in my net. I carefully pulled her out and held her between my thumb and forefinger, so that I could pinch her thorax and break her flight muscles; a trick that was passed down to me by more experienced entomologists. This would ensure that she could no longer move, an activity that might scrape off scales or tear her wings. Pristine specimens are the standard for insect collections.

A large, red and black Philippine Batwing Butterfly. You can see a hand holding the butterfly's wings. — Philippine Batwing Butterfly. Photo from iNaturalist. © LARKSPUR ALFORQUE, some rights reserved (CC-BY-NC)

By the time I boarded a plane to return home, my prized find had been decimated. Ants had found her, and eaten her abdomen. I was crestfallen and ashamed that I had killed her. Since that time, I largely stopped collecting insects for my personal collection. I limit my collection to two taxa (longhorned beetles and metallic wood boring beetles), to keep from killing and pinning every insect that I see. But I have been involved in the lethal collection of many insect specimens for my work, and it is not without the occasional pangs of guilt.

A recent news story profiled Master Gardener volunteers who had collected 25,000 bees in Pennsylvania to further scientific understanding of wild bee abundance and diversity in the state.¹ As the story was shared on social media, the comments and concerns related to lethal sampling accumulated: why was it necessary to kill the bees we are supposed to be helping?

In this article, I briefly examine the science, politics, and ethics of lethal sampling.

The Science

I know of only one study that has directly examined the impact of repeated, lethal sampling on insect communities.² In this study, the authors sampled wild bees every two weeks throughout a season, or once per season. They found no effect of repeated sampling on any of the response variables they measured, including bee abundance, species richness, or community composition. They suggest that density-dependent competitive release may explain their results: decreased survivorship by some is compensated by increased fecundity from others. In essence, as you remove bees from the community, it reduces the intensity of competition and allows surviving bees to produce more offspring than they would have been able to if they had to compete with other bees for resources.

Lethal sampling has long been the rule in studies of insect biodiversity. In homage to the “lock and key hypothesis,” which suggests that genital morphology acts as a reproductive barrier that ultimately defines a species, identifying an insect to species may mean dissecting out genitalia for microscopic examination. In fact, there is a piece of equipment that some entomologists use, that is designed to inflate and harden insect genitalia, called a phalloblaster or vesica everter. This penis pump for insects cost $2,727 in 1997.

A shift away from lethal sampling has been happening for quite some time, particularly for butterflies and other large insects that can be identified by sight. On iNaturalist, many insects are identified to species by combining advances in machine learning and computer vision with crowd-sourced verifications from the iNaturalist community. The platform has led to the discovery and rediscovery of multiple insect species.^{3, 4}

A few of the 2,691 specimens collected for a recent study of garden bee biodiversity. Photo credit: Gail Langellotto.

The Politics

Insects are generally exempt from regulatory oversight. But recent stories of insect declines and the emergence and growth of the insect farming industry has led at least one law school to teach a course on insect law. Institutional Animal Care and Use Committees (IACUC) govern the ethical care of animals used in research studies, but exempts invertebrates from oversight, except for cephalopods (octopus, squid and cuttlefish).

Few laws govern the collection of insect specimens. However, in the state of Washington, insects are classified as wildlife. Permits are required to collect insects for scientific study. This has complicated the launch of the Washington Bee Atlas, run by the Washington Department of Agriculture, which must secure permits from the Washington Department of Fish and Wildlife for every bee collected.

The Ethics

The cephalopod exemption to IACUC oversight is notable, and is based on the recognition that cephalopods are sentient, self-aware, and capable of feeling or fearing pain. Insects don’t have a brain, per se. Instead, they have three clusters of nerve fibers, which form the supraesophageal ganglion. This fact has sometimes been used to argue that insects can’t feel pain, but reviews of recent studies suggest that there is evidence that some insect adults may feel pain,⁵and that some may feel emotional states such as stress.⁶

Another high-profile study found evidence that bumblebees play.⁷ Play is classified as an activity that does not result in an obvious reward or adaptive outcome, among other criteria. In this study, researchers documented bumblebees interacting with balls in ways that satisfy the criteria for play. The bees received no reward for this behavior. As in many other animals, younger bees played more often than older bees. If insects are sentient, the field of entomology would undergo a revolution of practice.

Conclusion

Insects are so diverse. Many have yet to be discovered and described, and many others look remarkably similar. The only way to identify most insects to species is to have a physical specimen in hand that you can manipulate and examine under a microscope. And it’s notable that a landmark study of insect declines over 27 years used non-selective Malaise traps to enable the capture and counting of what must be tens of thousands of insects.⁸ It is extremely difficult to study many questions of insect ecology without lethal sampling.

But scientists are increasingly using and improving nonlethal methods in entomology,⁹ including the use of DNA barcoding, catch and release, and camera traps. Because the study of insects has largely been exempt from regulatory oversight, most entomologists have yet to reflect on the moral considerations of catching and killing insects. However, as we learn more about insect cognition, the time may be coming to carefully weigh the costs and benefits of lethal collection methods and to invest in technologies that advance the use of non-lethal options.

Aa solar-powered camera trap, to study insect visits to an artificial flower platform. On a single pole is mounted (from top to bottom) a solar panel, camera in protective white housing, and yellow flower platform. — An example of a solar-powered and open sourced camera trap, to study insect visits to an artificial flower platform. Photo by Maximilian Sittinger. (CC-BY-SA-4.0).

¹Stimpston, Ashley. 2024. Twenty master gardeners have collected 25,000 bees. Here’s why. The Washington Post (October 24, 2024).

²Gezon, Zachariah J. et al. 2015. The effect of repeated, lethal sampling on wild bee abundance and diversity. Methods in Ecology and Evolution, 6(9): 1044-1054.

³Tugwell, James, Masashi and Gaston, Kevin J. 2024. Sixteen insect species photographed for the first time by citizen scientist. ABC News, Australia (October 19, 2024).

⁴Mesaglio, Thomas. 2021. First known photographs of living specimens: the power of iNaturalist for recording rare tropical butterflies. Journal of Insect Conservation, 25: 905-911.

⁵Gibbons, M. et al. 2022. Can insects feel pain? A review of the neural and behavioral evidence. Advances in Insect Physiology, 63: 155-229.

⁶Lambert, H. et al. 2021. Wouldn’t hurt a fly? A review of insect cognition and sentience in relation to their use as food and feed. Applied Animal Behavior Science, 243: 105432.

⁷Galpayage Dona, Hiruni Samadi et al. 2022. Do bumblebees play? Animal Behavior, 194: 239-251.

⁸Hallman, Caspar A. et al. 2017. More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLOS One, 12(10): e0185809.

⁹Lovei, Gabor L. and Ferrante, Marco. 2024. The use and prospects of nonlethal methods in entomology. Annual Review of Entomology, 69: 183-198.

Garden practices for a wildlife-conscious fall

Posted on October 15, 2024 by Jen Hayes

1. Don’t use fake spider webs

Fake spider webs can be dangerous for wildlife both small and large. The webbing is fine enough to trap insects like bees and butterflies, and strong enough to ensnare small mammals and large birds like Western Screech Owls. Wildlife rehabilitators receive calls to rescue birds, chipmunks, and other animals from webs every fall (Cotroneo, 2020). Consider allowing spiders themselves to set up webs in your bushes, or keeping your fake webs as an indoor-only décor item.

2. Keep your pumpkin out of the landfill

Have you considered where your pumpkin goes, once it’s begun the inevitable post-Halloween rot? According to the USDA, 22.4 million pounds of pumpkin went unused last year (USDA, 2024). This number accounts only for pumpkins unharvested (left in the field). But this statistic doesn’t consider the pumpkins we waste by throwing them into the trashcan at the end of the season. You can reduce the number of pumpkins that wind up in landfills by 1) eating your pumpkin, 2) composting it’s remains or placing it in a yard-waste bin, or 3) donating your pumpkin to feed livestock, such as pumpkins for pigs! Every part of a pumpkin is edible, even pumpkin guts.

3. Leave the leaves, if you can

Leaves play an important role in both carbon storage and natural decomposition cycles (Ferlauto et al., 2023). Fallen leaves also provide shelter for many invertebrates that aren’t active through the winter, including queen bumble bees, firefly larvae, and caterpillars. If you must remove leaves from pathways, consider using them to mulch garden beds, or otherwise keeping them on your property, rather than disposing them.

4. Turn off lights for migrating birds

Fall is one of the two peak seasons annual bird migrations. Nocturnal migrators may be drawn into urban areas by artificial light, which can lead to disorientation and possible death. Collisions with buildings kill hundreds of millions of birds across North America annually (Van Doren et al., 2021). You can reduce your impact on light pollution by turning your exterior lights off, and pulling down blinds in rooms with windows where lights cannot be turned off or dimmed. In Oregon, peak fall migration is expected to be between September and October (Bird Alliance of Oregon).

5. Plant species with multiple benefits

Fall is one of the best times of year for introducing new plants into garden spaces. When planting this fall, consider plant species that bring beauty to your garden and provide resources for wildlife. Many shrubs and trees that support pollinators also provide seeds and berries that can feed birds or small mammals. Some of the top Pacific Northwest annuals and perennials for pollinators may also provide pest control services by supporting beneficial insects and predators.

6. Share something you learned here with others

We’ve created a companion Instagram post to share the information presented in this blog. Share our post to help spread helpful information that could positively benefit wildlife this fall!

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References

Anderson AG, Locher L, Hayes JJ-M, et al. 2022. Native Plant Picks for Bees. Corvallis, OR: Oregon State University Extension Service Report No.: EM 9363. Available from https://extension.oregonstate.edu/sites/default/files/documents/12581/native-plant-picks-bees-090122.pdf.

Cotroneo C. Why Those Fake Spider Webs Are a Bad Idea. Treehugger. Available from https://www.treehugger.com/fake-spider-webs-bird-deaths-danger-4863065.

Ferlauto M, Schmitt L, Burghardt K. 2024. Legacy effects of long-term autumn leaf litter removal slow decomposition rates and reduce soil carbon in suburban yards. PLANTS, PEOPLE, PLANET. 6(4):875–884. https://doi.org/10.1002/ppp3.10499.

Lights Out. Bird Alliance of Oregon. Available from https://birdallianceoregon.org/our-work/protect/habitat-and-wildlife/urban/reducing-wildlife-hazards/bird-safe-building/lights-out/.

Mitchell SR, DeBano SJ, Melathopoulos A. 2023. Shrubs and Trees for Bees. Corvallis, OR: Oregon State University Extension Service Report No.: EM 9391. https://extension.oregonstate.edu/sites/default/files/documents/12581/shrubs-trees-bees-em-9391.pdf

United States Department of Agriculture, National Agricultural Statistics Service. 2024. Vegetables 2023 Summary 02/12/2024. United State Department of Agriculture National Agricultural Statistics Service Vegetables Annual Survey.

Van Doren BM, Willard DE, Hennen M, et al. 2021. Drivers of fatal bird collisions in an urban center. Proc. Natl. Acad. Sci. U.S.A. 118(24):e2101666118. https://doi.org/10.1073/pnas.2101666118.

All photos were taken by Jen Hayes and may not be reproduced in any form without explicit permission.

Calling All Gardeners in Corvallis and Portland

Posted on April 25, 2024 by Nina Miller

My mother introduced me to gardening at a young age, growing parsley, tomatoes, marigolds, and basil. With spending much time in the garden, so came spending time with the insects. We would catch bumble bees in little jars to look at before letting them continue with their day. We would ooh and ahh over the butterflies that would visit our lilac bush in the late spring. With learning to garden came an interest in insects that I could not shake. With optimism that I would find a field that I would connect with, I started my voyage within academia in general Biology. Through a series of university transfers and focusing my passions, I graduated with a bachelor’s degree in Botany and Entomology from Oregon State University in September of 2023. During my time as an undergraduate student, I came across a paper discussing pollinators in the Arctic. I knew little about the process of pollination in an environment of such varying climates, and soon came to learn that flies were one of the most predominant pollinators in this curious ecosystem.

I took this image in 2021 of the garden space I was lucky to spend my time in. Featured is my beautiful dog, Francis, who is also a fan of insects!

Thus began my exploration into the world of fly pollinators. Underexamined and typically unassuming, I became enamored by these curious insects. As I was living between temperate and continental climates, moving from British Columbia, Quebec, New York, and Oregon, I looked to the ecosystems that I interacted with. Though “flashier” than the arctic muscid fly, as seen in the compelling report by Tiusanen et al. (2016), flower flies became both my academic and personal ardor. Also known as hover flies and syrphid flies, flower flies are integral pollinators in urban environments. Stopping at the flowering bushes and herbs during the blooming seasons to hunt for the flower flies and watching videos about them during the colder months, I ceased to subdue my fascination.

A beautiful image of the flower fly, Eristalinus aeneu. Photo by: Gabe Schp (CC0 1.0). Source: https://www.inaturalist.org/photos/206410832

During the final term of my undergraduate degree at Oregon State University, I met Dr. Langellotto who shared my adoration for flower flies. Dr. Langellotto introduced me to the predatory nature of flower fly larvae, expanding my once-exclusively lens of flower flies as pollinators to flower flies as essential managers of insect pests, such as aphids and mealybugs. Under the expert advisement of Dr. Langellotto, I began my master’s degree at the beginning of April 2024 and have dedicated my thesis project to my flower fly friends. As an ode to all invertebrate and vertebrate pollinators, entomologists, gardeners, citizen scientists, and nature-enjoyers, I hope that my research project calls to you.

Image of predatory Dioprosopa clavate larva consuming aphids. Photo by: Juan Carlos Fonseca Mata (CC BY-SA 4.0). Source: https://commons.wikimedia.org/w/index.php?curid=121246911

Thus comes my announcement for folks who garden. For this Summer 2024, the researchers of the Garden Ecology Lab are looking for people who garden in Corvallis or Portland, Oregon, to participate in a study of flower flies. In this study, student researchers of the lab will be examining how garden size, tree cover, and floral abundance changes the composition of flower flies. Excellent at mimicry, voracious predators of plant pests as larvae, and valuable pollinators as adults, flower flies are important insects in urban garden systems. Also known as hover flies or syrphid flies, they are often seen on warm and sunny days collecting nectar. We are looking for gardens of many kinds; whether it is entirely covered by trees, without trees, a garden with a great variety of flowering plants, an edible garden, a highly maintained garden, or a minimally maintained garden. A wide range of garden types will allow us to see patterns in what attracts flower flies to urban gardens.

If you are interested in volunteering your garden for the experiment of flower fly species composition, click on this link: https://docs.google.com/forms/d/e/1FAIpQLSeM01F-V1xL4LkU3FWXaADl62tgO0SVNT58IBiT4IgLM_EZww/viewform?usp=sf_link

In a second, more informal experiment, student researchers of the lab will be looking at food preference of flower fly larvae. We will look at flower flies that predate on aphids and if there are aphid species of greater interest to the larvae. To narrow down this study, we will look at Brassicas in edible gardens. Brassicas are a family of plants that include broccoli, cabbage, brussels sprouts, arugula, radishes, collards, mustard greens, and turnips.

If you are interested in volunteering your garden for the Brassica experiment, follow this link: https://docs.google.com/forms/d/e/1FAIpQLScIc5treQ5QezWxx58yovHdmPyfUZjKyVQP0aLrfwel_kxbpQ/viewform?usp=sf_link

If you are interested in sharing your garden in either of these studies, please submit your interest by May 20^th, 2024, following the surveys above. After this date, we will close the surveys and contact participants if they were selected by June 1, 2024. If selected, your garden will be surveyed once a month between mid-June and mid-October 2024.

References:

Tiusanen, M., Hebert, P.D.N., Martin Schmidt, N., & Roslin, T. (2016). One fly to rule them all- muscid flies are the key pollinators in the Arctic. Proceedings B, 283: 1839. https://doi.org/10.1098%2Frspb.2016.1271

Queer Entomology

Posted on July 26, 2023 by Jen Hayes

On the last day of pride month, I read an article that brought me to tears: Can Entomology Emerge as a Role Model Field of Study for LGBTQ+ Inclusion and Visibility? by Michael C. Cavallaro. This year has been extremely difficult for the LGBTQ+ community, and to read about the successes and progress made in my field towards LGBTQ+ inclusion warmed my heart and gave me hope for my fellow queer bug lovers.

Before we dive in to the article, I want to share why this topic is important to me. I identify as a queer entomologist in two ways: 1) I am queer and I am an entomologist, and 2) I am interested in the ways that entomology expands and defies western understanding and expression of gender. The natural world, especially insects, teaches us that queerness is inherently natural and expressed in diverse ways.

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Image description: An intersex bee from the genus Agapostemon. The right side presents characteristics that typify a female Agapostemon: green metallic abdomen, robust legs with pollen carrying hairs, shorter, thicker antennal segments. The left side presents male characteristics, including a yellow and black striped abdomen, yellow legs with fewer hairs, and elongated antennal segments.

Cavallaro begins the article discussing “Shared Traits: Entomologists and LGBTQ+ Folks” by Rae Olsson, which mirrors many conversations I have had with my fellow queer entomologists. Us folks who grow up chasing, collecting, and admiring insects tend to be viewed as weird, odd, or even outcasts. Queer folks are often far too familiar with the feeling of being marginalized, othered, and at odds with society. But, there is an odd comfort in knowing that you are a weirdo studying something weird.

The article continues, noting the advances that ESA (The Entomological Society of America) has made in providing an inclusive environment for LGBTQ+ folks and elevating their voices. We have seen these advances in the form of inviting people to include their pronouns on the annual event badges, introducing symposia on Diversity, Equity and Inclusion (DEI) issues, and removing states with anti-LGBTQ+ laws from potential future meeting locations. He also points out recently identified insects that have been bestowed names of queer icons, which I wrote about during last year’s pollinator week post.

IMAGE DESCRIPTION: A Cowpea weevil, which has long antennae and brown and white spots on its elytra. female cowpea weevils are known to mount other female cowpea weevils. Photo © Gene H on iNaturalist.

Cavallaro reports that 7.2% percent of ESA members have identified themselves as LGBTQ+, which reflects the U.S. national average. He notes that STEM still has many barriers to overcome as it is “rooted in a competitive and heteronormative culture” and “workspaces for queer-spectrum STEM professionals and students can be unsupportive and exclusionary.” Both STEM and entomology still have a long way to go in terms of acceptance, encouragement, and representation of queer folks.

As someone who attended a prestigious field entomology program and was called a “disney princess” on the first day, I can attest to the flippancy with which queer folks and femme-presenting folks are often treated in professional entomological spaces. It is, however, validating to witness the largest entomological organization in the U.S. taking the time to address, welcome, and better their ability to support their LGBTQ+ membership.

Petal-cutting Bees!

Posted on January 27, 2023 by Mallory Mead

A study of leafcutter bees and a PNW native flower, through the lens of iNaturalist.

The Clarkia Project team: Mallory Mead, Jen Hayes, Sarah Erskine, and Ali Filipovic

If you are a subscriber to our blog, you have likely seen our photos and videos of one of our favorite plant-pollinator interactions: the petals of Farewell-to-Spring (Clarkia amoena) being harvested by leafcutter bees!

After observing this eccentric harvest behavior in the research garden, we got curious about the bees behind the petal-nest craft, and how we could study this interaction further.

Leafcutter bee mid-petal-harvest! Photo by Devon Johnson.

Crescent-shaped petal-cuts left behind by leafcutter bees.

iNaturalist is a popular community-supported biodiversity database that the Garden Ecology Lab has been experimenting with in recent years. Jen realized that the leafcutter bees’ distinct crescent-shaped mark are visible in many iNaturalist observations of Clarkia amoena. She wondered how we could use the already sizeable iNaturalist database of Clarkia amoena observations to study the interaction over a wider geographic and chronological scale than that of the research garden. Jen and Gail agreed to mentor me in producing an undergraduate research thesis on this subject.

The study’s objective is to use iNaturalist’s data on Clarkia amoena to see if there is a difference in leafcutter bee usage of Clarkia amoena petals based on whether the flower is a native versus a cultivar type, and whether the flower is found in an urban or non-urban environment.

In this process we have found that iNaturalist is easy for anyone to contribute to, but the information it provides is limited compared to the wealth of contextual information gained when being in the actual, living presence of a specimen. So, to get a greater feel for the intricacies of this flower, I embarked on what we called “Ground-Truthing Field Trips” to check out some Clarkia amoena populations in the “real world”.

I went out during peak pollinator season, following the coordinates of recently posted iNaturalist observations. Each specimen I visited was incredibly different from the next. I found the delicate blossoms in natural areas, the borders of farmland, restoration sites, and gardens.

Data from these trips will not be published in my thesis because the contexts are not exactly comparable, and my sampling was exploratory rather than precise. Nonetheless, I gained contextual insight and inspiration watching diverse pollinator assemblages in beautiful meadows of pink.

Mallory at a meadow restoration site near Corvallis with *Clarkia amoena* and tarweed (*Madia* elegans).

The field trips have helped us more clearly see through the window of iNaturalist and have informed the methodology we use.

For example, I saw examples of hybridization between two species of Clarkia in a seeded restoration site, and cultivar-hybrid escapees in natural areas. It’s been important to navigate identification of cultivars and hybrids in iNaturalist.

In a restoration prairie seeded with two different Clarkia species, pollinators cross-pollinate them, giving rise to sterile hybrids (Lewis & Raven, 1958). Note the malformed stigma and anthers.

Simultaneously, our field crew recorded petal-cutting behavior on the Clarkia amoena natives and nativars at Jen’s research garden this summer. Below are the three cultivars in the garden, and if you look closely you can see “petal-cuts” which we counted and recorded weekly. We will analyze the difference in leafcutter usage between the cultivars and native type.

This hot pink, stripy *Clarkia* doesn’t look like either the native or cultivars we had planted!

Clarkia amoena is an annual that reseeds itself effectively, so last year’s seeds gave rise to this season’s blooms. To our surprise, however, Clarkia amoena of all different colors started popping up in our research plots this Spring! Last season’s bees had combined pollen from the garden’s varieties bringing rise to all sorts of intermediate forms.

Clarkia amoena is prone to hybridization between members of the species or cultivars in the same proximity. These intraspecific hybrids are fertile. We seek to explore how cultivar genetics may be moving into natural populations.

Through the winter, our team is working with the iNaturalist data to quantify leafcutter bee petal usage. We expect to share our results in June 2023, so stick around to hear about our findings!

Work Cited:

Lewis, H., & Raven, P. H. (1958). Rapid Evolution in Clarkia. Society for the Study of Evolution, 12(3), 319–336.

What are bees doing right now? Fall Edition

Posted on October 13, 2022 by Mallory Mead

The sunny days are diminishing as summer rolls into autumn, and as the sun descends, the bees’ flight lulls to rest. Bees sense and respond to light and use the sun to orient themselves and navigate. Along with their two large compound eyes that are used for vision, bees have three simple eyes that sit atop their their heads in a triangular formation. These are called ‘ocelli’ and they sense light.

Originally posted by postgraduate student Hamish Symington, this video shows bees being studied by fellow student Kristina Buch in the Cambridge University Botanic Garden.

Ocelli can be seen atop the head between the compound eyes. Photo of bee from the genus Triepeolus by Mallory Mead.

There is a video circulating the internet of honeybees flying in an enclosure in a laboratory. The video shows the researcher turning off the lights in the enclosure, causing the bees to drop to the ground instantaneously, showing how honeybees will not fly in the absence of light.

We notice similar behavior in the field on days where clouds pass over the sun intermittently. When the sky is bright, our plants bustle with pollinators, and when shadows come over, most bees are suddenly out of sight. It makes sense that as the days get shorter and colder the sight of pollinators will become more and more fleeting!

Some bees are still coming out during the warm October afternoons, and collecting their final energy reserves for the winter. Goldenrod, Douglas’ aster, California poppy, bee balms, and black-eyed Susan, amongst other late blooming pollinator plants are still providing bees with nectar and pollen during this time of transition.

Purple Aster and goldenrod in a natural meadow. Photos by Mallory Mead.
Goldenrod in meadow.
A long horned bee and a sweat bee on black-eyed Susan (Rudbeckia hirta).
Metallic green sweat bee on Scabiosa.

During this season, honeybees and bumblebees predominate the landscape, while long-horned bees (genus: Melisoddes), leafcutter bees (genus: Megachile) and sweat bees (family: Halictidae) can still be seen as they finish up resource collection in the Willamette Valley.

Social bees

Honeybees must make enough honey before temperatures drop and they can no longer leave the hive, so you’ll find them foraging for pollen and nectar as late in the season as possible.

In late summer and fall we begin to see an influx of bumblebee queens. During the summer, the queens are busy reproducing in their underground hives, while worker bees take to the landscape. However, near the end of the foraging season, new queens hatch and fly out to find mates and food. You may see bumblebee queens getting their last bits of food energy before overwintering, while the rest of the colony (males and workers) dwindle away.

Black tailed Bumble Bee (Bombus Melanopygus) © Erin Forrester, some rights reserved (CC-BY-NC)

Check out this guide to Bumble Bees of the Western United States to see which Bombus species are found in your region and what time of year they are active.

Solitary Bees

Leaf, mud and petal nests are capped and ready for winter! Photos by Mallory Mead.
Petal nest in bamboo.

Many solitary bees are finishing their last nests where they’ve laid eggs for the next generation of their species.

If you care for nest boxes in your garden be sure to take appropriate steps to bring your bees indoors and clean their cocoons. Check out the Linn Master Gardener Association Bee Notes email list to receive timely emails about the seasonal steps of caring for mason bees.

When solitary adult bees finish reproducing and nest building, their work is done, so they die off. But small carpenter bees, from the genus Ceratina, are an exception. Ceratina females remain as late into the cold season as they can muster in order to guard their nests.¹ These protective mothers fend off predators, pests and parasitoids that try to invade the nests.

*Ceratina acantha* © vespidmacro, some rights reserved (CC-BY-NC)

This fall, we hope you are able to see some of the last glimpses of bees of the year!

This post concludes our series on what the bees are doing right now! Thank you for taking part in this seasonal journey through the lives of bees in the Willamette Valley.

Source Cited:

1: Danforth, B. N., Minckley, R. L., & Neff, J. L. (2019). The solitary bees: Biology, evolution, conservation. Princeton University Press.

The Underappreciated Syrphid Fly

Posted on August 23, 2022 by Devon Johnson

A syrphid flying over a clarkia, photo by Devon Johnson

We have been seeing syrphid flies (family: Syrphidae) in great abundance this summer over at the Garden Ecology lab’s research garden, so much so, that our field research team has begun to call it the year of the syrphids! These bee-mimicking, skittish pollinators have particularly loved the native and cultivar yarrow we have planted in our plots. Although their abundance has recently dipped–likely because Yarrow (Achillea millefolium) is done with its first round of bloom–we still see them buzzing around.

Syrphid flies, also known as flower flies or hover flies are a common visitor of gardens. You may see them buzzing around bright flowers or fighting mid air. They are important pollinators and feed off of nectar and pollen in their adult stage. Additionally, in their larval form, they are great at reducing aphid populations, but are extremely susceptible to pesticides.

Line drawing of *Toxomerus* spp. life cycle, credit to Brett Blaauw, Department of Entomology, Michigan State University

The life cycle¹ of syrphids start with the adults laying eggs in leaves of infested plants. After about three days, they hatch into their voracious, blind, larval stage.

The larvae feast on small pests like aphids, leafhoppers, scales, and thrips. The larvae do this by moving along plants, lifting their heads to try and seize and pierce their prey with their triple-pointed dart inside their mouth². After slurping their prey dry, they will discard the exoskeleton.

Larvae will develop through a few instars and after 1 to 3 weeks will go into a pupal stage on the host plant or on the soil. After two weeks, an adult emerges.

Syrphid larvae with an aphid in its grasp. Photo by Oregon State University

Hover fly pupa. Attribution © Adam Grimwade, all rights reserved⁵

In the pacific northwest, our common syrphid is Scaeva pyrastri. It is unique in that rather than overwintering as a larvae, S. Pyrastri overwinters as an adult. Three to seven generations occur in a year, with possibility for the higher counts depending on the region and species. Another species, originally native to Europe, the drone fly (Eristalis tenax³) is named after male honey bees because it is mimics them so well. Other mimics in Syrphidae lay their eggs in the nests of bumblebees or social wasps, where the larvae eat dead bees and detritus.

Their quick movements and bee-like appearance can make syrphid flies hard to identify.

To identify a flying insect as a syrphid, look for a single pair of wings. Flies (Order: diptera) do not have a second pair of wings like bees. Instead they have a vestige of hind wings called halteres that look like little nubs beneath their wings. These act like gyroscopes to help the fly balance during unique in-flight maneuvers. Also look for large, forward facing compound eyes typical of any dipterans. In our lab, we’ve see a wide range of size and different colors. Syrphids can be anywhere from a tenth of an inch to half an inch long, and have black or brown bodies with white or yellow spots and stripes. Fun fact: most hover fly mouths are extendable ‘sponges’ that mop up nectar and pollen.

Common oblique syrphid (*Allograpta obliqu*a). Notice the nub-like halteres below the wings. Photo by Ron Hemberger

Flower flies are extremely important to pest control and pollination, 40% of syrphid species larvae feast on the previously mentioned prey, and each larvae can eat up to 400 aphids during development!

Unfortunately, the larvae of syrphids are similar to many other species so are hard to identify. However, they are usually on pest infested plants and may be seen near adult syrphids. Look for their typical ‘stretching’ behavior while they are on the hunt. If you have a pest problem, avoid using pesticides or insecticides! These kill the syrphids that can help with pests. Instead, promoting syrphids or other pest eaters like ladybugs and lacewings by providing a variety of insectary plants can help you in the long run.

A large syrphid on our native yarrow, with a threat nearby! Photo by Devon Johnson

As previously mentioned, yarrow (Achillea millefolium) has been our most successful syrphid-attracting plant in our lab this year. Syrphid flower preference varies based on the subfamily, according to studies. The subfamily Eristalinae is attracted to white flowers, Pipizinae prefer white and yellow, and Syrphinae is more general. Link to an article going more in depth on syrphid flower preference here⁴.

Not coincidentally, native yarrow is primarily white, while our cultivars are yellow and pink. Observationally, syrphids visit yellow yarrow at a similar rate as they do the native, while our pink cultivar saw next to no syrphid visitors. We recommend planting yarrow as well as a variety of native flowering plants to support these pollinators. Leave leaf litter and debris around flowering plants, too. These provide protected overwintering sites which syrphids rely on⁷.

Syrphid on our yarrow ‘Moonshine’ cultivar. Photo by Devon Johnson

Currently, no syrphid species are on the U.S. Endangered Species Act lists, but like many insects, this underappreciated pollinator is understudied and biodiversity of this group is not well tracked. In Britain, however, some hoverflies have been placed on their Biodiversity Action Plan.⁶

Whether syrphids are endangered or not, we can help biodiversity by promoting native pollinators and planting native plants in our yards and gardens.

Credits

New Summer Game- Pollinator Bingo!

Posted on August 10, 2022 by Svea Bruslind

We are entering the heart of summer, with blue skies, rising temperatures, blooming flowers, and growing gardens. As some of us are taking this time to relax in the bounty of our gardens and in whatever shade we can find, our pollinator counterparts are in the middle of their busiest season. The pollinators are out in full force, and it seems almost impossible to turn around in a garden without spotting a new butterfly, bee, or beetle. So for those among us who want to engage even further with the friends visiting our gardens around this time of year, we have the perfect game for you: Pollinator Bingo!

Our Pollinator Bingo-or should we say BEEngo- is a healthy mix between Bingo and a scavenger hunt!

Here’s how to play:

Select the Bingo Card you will use
Download it, or print it out, and get it ready to be filled out
Keep your eyes open for these visitors in a garden. When you spot a pollinator on your Bingo card, mark that pollinators square.
Once you fill an entire row (horizontal, vertical or diagonal) you’ve won your BEEngo!
Extra Credit Challenge: Try to black out the entire card!

We hope you have fun playing Pollinator Bingo outside, exploring and enjoying the natural world in some way. Good luck BEEngo players!

Pollinator Bingo Board 1 Download

Pollinator Bingo Board 2 Download

Below, we included some pollinator spotlights, so you can get to know some of the species on your Bingo card a little better!

Pollinator Bingo Spotlight List:

Tribe Eucerini, Longhorned bee

Eucerini, also known as long-horned bees, are favorites among our lab members. They are the most diverse tribe in the family Apidae, with over 32 genera. These bees are solitary and ground-nesting. What makes them distinct and a lab favorite are the long antennae the males are known for and from which they get their common name. The females are also recognizable, as they have long hairs, known as scopae, on their hind legs, giving them the appearance of wearing very thick pants.

2. Species Papilio machaon oregonia, Oregon Swallowtail butterfly

As with any in the Swallowtail family, Papilio machaon oregonia, or the Oregon Swallowtail, is big, beautiful, and eye-catching. It was officially named Oregon’s state insect on July 16, 1979. It is native to the northwest and is only found in Oregon, Washington, Idaho, and sections of British Columbia. For the purposes of Pollinator Bingo, any Swallowtail will count for its space. Keep an eye out for the Oregon Swallowtail and others, and see how many different species you can find!

3. Family Syrphidae, Flower Fly

Hoverflies, flower flies, and syrphid flies are all different names for the flies within the family Syrphidae. Syrphid flies come in a wide variety of sizes and colors, with some that resemble wasps and others that look nearly identical to bees. Most syrphids, however, can be found with some kind of striping on their abdomen. Syrphids are essential to any garden as they help with pest control and pollination. Some people are surprised that flies are pollinators too, but hopefully, this list can illustrate the wide variety of pollinators out there!

4. Species Trichodes ornatus, Ornate Checkered beetle

Trichodes ornatus, or the Ornate Checkered beetle, is an interesting species, as during the early stages of its life, instead of pollinating, it feeds on pollinators. These beetles will lay their eggs on plants such as yarrow, sagebrush, and asters. When these eggs hatch, the larvae attach themselves to a visiting bee, usually a leafcutter bee. They will then be transported to the bee’s nest, where they will eat the provisions left there for the host larvae before eating the host larvae and burrowing into nearby cells to do the same. As an adult, the Ornate Checkered beetle will feed on pollen but will not miss an opportunity to snack on other visiting pollinators when foraging for pollen.

Attribution © LapisOre some rights reserved (CC by lapis_the_mothman iNaturalist user)

5. Species Calypte Anna, Anna’s hummingbird

Calypte Anna or Anna’s hummingbird should be a familiar sight for many of us. This rambunctious bird is a permanent resident along the Pacific Coast, staying year-round through winters instead of engaging in migration as other species of hummingbirds are known to do. Males of Anna’s hummingbird are pretty talkative, often vocalizing with a buzzy song. The males have a brilliant red head with a green body, and the females have similar green plumage, but without the red coloration on their face and neck.

Attribution © selwynq some rights reserved (CC by selwynq iNaturalist user)

What are bees doing right now? Summer Edition

Posted on July 25, 2022 by Mallory Mead

Summer is the main active season for many bee species. After a wet spring in Western Oregon, the sun is out and our world is in bloom!

So what are summer bees up to right now? The main events of the season are…

Foraging for nectar and pollen
Finding mates and laying eggs
Excavating, finding and building nests for offspring.

Adult bees also experience predation by spiders and birds during this time. This Crab Spider caught a female long horned bee in its jaws!

A female long horned bee caught by a crab spider on Douglas’ Aster.

So who exactly is out and about in your garden at this time of year?

Bumblebees and honeybees visibly dominate the landscape throughout the summer, but lean in closer to your flowering plants and you’ll find the smaller sweat bees (family: Halictidae), long horned bees (genera: Melissodes and Eucera), leafcutter bees (genus: Megachile) and small carpenter bees (genus: Ceratina). Although there are many others amid the vast diversity of bee species science is only beginning to understand, these are some common garden visitors. We’ll go through each group and their summer activities.

Notice the two adomenal segments beneath the yellow stripe of this male yellow-faced bumblebee (Bombus vosnesenskii). Photo by Jen Hayes.

The presence of pollen on a bee especially carried in pollen baskets, is a good indicator that the bee is a female. Photo by Jay Stiller-Freeman

Bumblebees: By summertime, most queens have established colonies of workers who do the foraging for the hive, so we see less large queen bumblebees and more smaller workers as the season progresses. Later in the season, queens lay male eggs as well as eggs for the next generation of queens. Male bumblebees take to the landscape in mid to later summer, recognizable by their additional segments on their abdomen, long antennae, and by the fact that they don’t carry pollen like females do. Males do not have stingers, so if you can confidently identify male bumblebees, they are fun to play with while they’re waiting around for new queens with which to mate. You’ll find them sipping on nectar-rich plants like lavender, herbs, asters and heal-all.

Honeybees: Summer is prime time for honeybees! Worker populations are at their peaks; pollen and nectar are flowing. As hive population size rises and available hive space remains static, honeybees may organize a swarm. In this process, the current queen lays new queen eggs and part of the colony joins her to lift off and leave the colony in search of a new cavity to make their home. Swarming is considered a form of colony-level reproduction supporting the idea that honey bee colonies are super organisms. Swarming is common in spring and early summer. Beekeepers add new boxes to hives so prevent their colonies from swarming.

Late summer is mating season for honey bees. Males and new queen eggs are laid and emerge to mate with individuals from other colonies. Honeybees mate in the air at heights ranging between 15 and 60 m¹.

A yellow-faced bumble bee and a honey bee sip nectar from lavender. Photo by Devon Johnson.

Sweat bees

Sweat bee on California Poppy ‘White’. Photo by Tyler Sato Spofford.

A halictid dear to our hearts at the Garden Ecology Lab is the metallic green bee (genus: Agapostemon). While females provision nests in the soil, you can find males resting in congregations on flowers in the evening time and early morning!

Sweat bees are one of the most common groups of “small” bees you’ll find in your garden. They forage on a wide variety of plants and come in a wide range of sizes, but most have striped abdomens, and all carry pollen on their hind legs and nest in soil.

Agapostemon virescens male congregation.

A male long horned bee from the genus Eucera on a California Poppy ‘Purple Gleam’. Photo by Jen Hayes.

Long Horned bees

Long horned bees are most active on our research plots in the mid to late summer. I love this group because they are so easy to recognize. Males have antennae that are way longer than other bees’ relative to their bodies. The females, who bear antenna of normal lengths, are still easy to spot because they have long feathery scopa (or hairs) on their hind legs for collecting pollen that they absolutely pack with pollen while foraging.

Long horned bees are sometimes referred to as “sunflower bees” for their love of foraging on sunflowers.

Long horned bees nest in the soil², so when you see them take it as a reminder to leave some uncovered, undisturbed soil in your garden for these bees to persist!

Notice this female long horn’s feathery pants! Photo by Mallory Mead.

A relatively large small carpenter bee. Photo by Mallory Mead.

Small Carpenter bees

When I point out small carpenter bees (genus: Ceratina), most of my friends can’t believe they are bees. They think they are some kind of flying ant. Their bodies are sleek, and often shimmer with a green or blue reflective gleam.

Small carpenter bees are considered wood excavators as they dig out the pith from dry plant canes for their nests. Ceratina are a unique group in terms of their parenting style. Unlike other solitary bee mothers, Ceratina mothers guard their offspring even after their offspring have developed into adults. Mothers stick around as long as they can until Winter falls.²

Leafcutter bees

Leafcutter bees (genus: Megachile), as their names suggest cut leaves from their host plants! They use these bits of leaves to line their ground and cavity nests, to waterproof and protect their offspring.

Leafcutter bees are from the bee family Megachilidae, a family known for creative nest building. Bees in this family were supposedly able to expand their ranges due to their flexibility in nesting site and material. They’ve been found nesting in wood, porous stones, stems, galls, and even snail shells filling these various cavities with leaves, mud, plant resins, pebbles, straw and even petals². The fascinating nest building behavior we’ve gotten to witness in the field is petal cutting of Farewell-to-Spring (Clarkia amoena) blooms.

We can track the usage of Farewell-to-Spring petals by leafcutter bees due to the signature crescent shape left behind on the flowers.

Thank you for joining us on this exploration of some of Oregon’s summer bees and what they are currently doing! We will release one more blog post in this series. Be sure to subscribe so you don’t miss the next in the series!

Sources

1: Landscape Analysis of Drone Congregation Areas of the Honey Bee, Apis mellifera by Galindo-Cardona et. al, 2012. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3635128/

2: The Solitary Bees by Bryan N. Danforth, Robert L. Minckley, and John L. Neff. 2019.

Pollinator Week 2022

Posted on June 23, 2022 by Jen Hayes

Happy pollinator week and first official week of summer! ☀️🐝🦋

Pollinator week is an annual celebration in June to emphasize the importance of pollinators and their health, started by the Pollinator Partnership. To celebrate pollinator week, we’re going to share some information with you about a few of our favorite pollinators and a few others deserving recognition. June is also Pride Month, so we are going to start with a fun fact connecting pollinators and Pride! 🌈

Did you know there are pollinators named after drag queens? A new genus of soldier flies were discovered in Australia 2020 and given names that are indicative of their metallic and rainbow-colored bodies! Among Opaluma fabulosa, O. iridescens, O. opulens, O. sapphira and O. unicornis are O. rupaul, named after the drag queen RuPaul, and O. ednae, named after the Australian drag queen Dame Edna.

Soldier flies belong to the Stratiomyidae family, which include many flower-visiting flies! Many adult soldier flies visit flowers for nectar and subsequently transfer pollen on their bodies as they travel from one bloom to the next. Six of these seven Opaluma species were impacted by the Australian bushfires in 2019 and 2020; their recent taxonomic identification will allow them to be monitored in recovery efforts following the fires. The full citation for these stunning soldier flies can be found here.

To stay on the theme of iridescence, next we will share some information about my (Jen’s) favorite pollinators: Orchid bees! Orchid bees are in the same family as bumblebees and honey bees (Apidae) but are found within their own tribe, Euglossini. Within Euglossini, there are only five genera: Algae, Euglossa, Eulaema, Eufriesa, and Exaraete. Only one species of orchid bee is found in the United States (Euglossa dilemma), with the majority being found in Central and South America.

Not all orchid bees are iridescent– bees from the genus Eulaema are the exception, which are more similar in appearance to bumblebees than they are to the metallic members of Euglossini. I find orchid bees to be mesmerizing, not only because of their novel color forms, but also their unique adaptations. Some orchid bees’ tongues (proboscises) are more than 1.5 times their body length in order to access nectar located in long, tubular flowers! These bees often fly with their proboscis tucked under their body, and it may look like a small tail as it trails past their abdomen.

Photo © sixlegs on iNaturalist,
all rights reserved.

Euglossa have highly modified tibias on their hind legs. Male members of Euglossa species have a “pouch” on their tibia, used to collect and store floral fragrances from flowers in the form of essential oils. These oils are later used to attract potential mates. I like to think Euglossine males would be excellent candle makers.

Mallory’s favorite pollinators are long-horned bees, in particular those from the genus Melissodes, which are highly abundant in the latter half of our field season! Mallory loves long-horned bees because they have many traits that make them easily identifiable in the field. Males have elongated antennal segments which are indicative of their common name ‘long-horned’. They often have interesting colored eyes as well- some of the specimens we collect have green, blue or grayish eyes that contrast greatly with their often blond-colored hair (scopa). Her favorite trait, however, is the scopa on their hind legs. When full of pollen, long-horned females often look like they have ‘pollen pants’ on, in contrast to the neat and tidy pollen baskets seen on bumblebees! Svea thinks their pollen pants make long-horned bees look like they’re wearing a pair of western-style chaps. Melissodes primarily pollinate species from the Asteraceae, with specialization occurring on asters, daisies, and sunflowers. Sometimes Melissodes are called ‘sunflower bees’.

*Melissodes sp.* visiting a cosmo, photo by Mallory Mead.

Photo © armadillocommander on iNaturalist, some rights reserved (CC BY-NC).

Svea’s favorite pollinator is Anna’s hummingbird (Calpyte anna). C. anna is one of seven hummingbird species native to Oregon. Svea enjoys watching Anna’s hummingbird as a pastime at her parents’ house: they have a small, active community of hummingbirds that are very vocal and can be seen fighting over their nectar sources (including their butterfly bush and hummingbird feeder).

Svea also mentioned that the males are particularly pretty, though it requires a particular angle of light to make their iridescent copper-red colored throats glow. The ‘Anna’ in Anna’s hummingbird comes from the French Duchess of Rivoli, Anna Masséna, who was part of the court of France’s last empress (Eugénie de Montijo, 1853-1870). Anna’s hummingbirds are important pollinators in California, where they feed from coastal chaparral flora that share a similar phenology (breeding and feeding patterns) with the pollinator.

Nicole is another member of the lab whose favorite pollinator is a hummingbird! Nicole’s favorite pollinator is the Rufous hummingbird Selasphorus rufus. The USDA Forest Service describes the Rufous hummingbird as “small but feisty long-distance migrant[s]”. They are small in size and feisty in their protection of their feeding territories, they have been known to chase off other hummingbirds, large insects, and even people! Some of their preferred host plants include morning glory (Ipomoea arborescens), ocotillo (Foquieria spp.), shrimp plant (Justicia spp.) and red-colored blooms from the mint family, such as Salvia elegans and Stachys coccinea. Nicole loves the Rufous hummingbird because she regularly saw them while she was growing up. They could regularly be seen foraging and defending their territory in her parent’s yard.

Photo © Wendy Feltham (wendy5 on iNaturalist), all rights reserved.

Cara’s favorite pollinator is the Western Tiger Swallowtail Papilio rutulus. This magnificent butterfly can be commonly found at Cara’s research plantings of butterfly bush (Buddleja spp.), and can also be spotted basking on yarrow or slowly fluttering along the hedgerows at Oak Creek Center for Urban Horticulture. Despite the name ‘butterfly bush’, Cara has found butterflies to be infrequent visitors of Buddleja, though of the few butterfly visitors they receive, the Western Tiger Swallowtail is the most common. Cara additionally grew up seeing swallowtails every summer, which is why they are her favorite pollinator! To read more about this swallowtail, check out Lucas’s Pollinator of the Week Post.

Garden Ecology Lab

Socio-ecological research in urban and suburban garden systems

Category Archives: Beneficial Insects