Tag Archives: Cynthia Brast

More on Western Tent Caterpillars (Malocosoma californicum pluviale)

The Western Tent Caterpillar is probably one of the most studied and also one of the most loathed insects in the Pacific Northwest. I’m hoping to change attitudes by shining a light on some of the ecological facets of the species and how it connects to the larger food web. We often deem something a pest before really considering the whole picture. Is there anything good about a caterpillar eating leaves off a tree? It depends on a lot of factors. Why not take time to examine the web…and I’m not referring to the tent here either.

It was just last week in my community (San Juan Island), that I heard a story about a woman who fell and hit her head after getting on a ladder to BURN the tent caterpillars out of her fruit trees. Hmmm. Please don’t try this at home. It isn’t safe. Burning the tents out of trees can actually do more damage to the tree than the caterpillars do by eating the leaves.

The photos below show something that happens to the tent caterpillars we may not notice in our panic to eradicate them from our trees. The egg on the caterpillar was laid by a parasitic Tachinid fly. It chose the head, so the caterpillar can’t chew it off its body. The egg is shed when the caterpillar molts, but the fly is already developing inside the caterpillar. It will literally eat the caterpillar from the inside out. So, when you clip off those tents and throw them into the fire, you are also killing the natural and best pest predators along with them. Naturus interruptus! We do more harm than good by intervening.

Western Tent Caterpillar with Tachinid Fly egg on head
Western Tent Caterpillars (Malocosoma californicum pluviale) with deceased individuals in background likely affected by nucleopolyhedrovirus 

The Western Tent Moth caterpillars are affected by a few other parasitoids. Braconid wasps also attack them. Some lay eggs on the cocoons. There is also a nucleopolyhedrovirus that infects them when populations are high. In my rush to get this out, I may come back and edit, but I’ve referenced lots of great information below so you can read more about this on your own.

To add to all of this, over the weekend, my daughter and I found some tents in the orchard trees on our property. I might just be the ONLY resident in the San Juans excited to see them. Hmmm. Well, what I found was even more interesting. The tents had dead caterpillars inside and living family groups of earwigs. We also found a super cute jumping spider!

I was curious about this because earwigs are known to be garden pests, I did find some studies about earwigs that are PREDATORY on species of Lepidoptera. While these studies addressed other species of moths, the gist was that the plant species sends out a chemical signal that calls pest predators when it is being attacked by caterpillars. Every plant and pest predator sends and responds (respectively) to various signals, some very specific to each relationship. The plant is calling in the army! It may not always be earwigs, but there are wasps, flies, and others that come to aid the plant when it is under attack. Yes, it is very cool!!!

Earwigs and Jumping spider eat tent caterpillars

Oh, and those Western Tent Caterpillars turn into adult moths in mid summer. They are attracted to light. Turn off your outdoor lights. Nature will thank you and you will be less attractive to the mating moths. Many moth species also tend to fly off en-masse when they are mate seeking. These periodic, seasonal pulses of terrestrial invertebrates in our region end up in nearshore marine habitats when they fly out over the ocean.

Various studies have surveyed the stomach contents of Chinook and Coho Salmon, and other fishes in nearshore marine habitats during their first year at sea. Two studies I found reported finding Western Tent Moths and Spruce Budworm Moths (species considered as pests in northern boreal forests) in sampled gut contents. Brodeur et al., (1987) reported the following from one survey, “The incidence of several juvenile coho collected after the storm which had stomachs that were distended with over 100 of these insects exemplifies the ability of these juvenile coho to readily exploit these allochthonous inputs into the marine environment.” They were referring to the “pest” species, (Choristoneura occidentalis) or Spruce Budworm Moth in this instance. In Brennan et al. (2002), sampling of salmon in Central Puget Sound found insect prey included Western Tent Moths (Malocosoma sp.), and that “Lepidoptera in 2002 diets were gravimetrically dominated by tent caterpillar moths (Malocosoma sp.) 51% of Lepidoptera category by weight.” They also reported that Lepidoptera in their samples “were only abundant in 2002.” Coincidentally perhaps, this was a year of a recorded outbreak of tent caterpillars in WA state.

Other studies acknowledge terrestrial invertebrates as a better quality food than marine crustaceans for developing salmon. Periodic, cyclic, or seasonal events resulting in abundant insect flotsam in marine habitats may be missed, or difficult to record, but undoubtedly play a role in feeding fish in nearshore marine habitats.

Take away point here. Even bugs we see as pests have a role in ecosystems. Salmon and other species of wildlife don’t have grocery stores to visit when they need a meal. They rely on seasonal and periodic availability of food. It’s all they have, and it’s important for us to appreciate that.

Please take a moment to scroll through some of the photos below. Definitely check out the fantastic animation by April Randall about the adult moths flying out over the shoreline and being eaten by salmon! Don’t miss checking out those references and reading material too. If you are curious to know more, shoot me an email and I’m happy to send you literature for further reading.

Thank you!

Malocosoma californicum pluviale with Tachinid fly egg on head
Malocosoma californicum pluviale caterpillars affected by nucleopolyhedrovirus 

Jumping spider eating Malocosoma californicum pluviale caterpillar (photo credit to Alex Maas and artistic rendering by Cynthia Brast-Bormann)
Parasitized Malocosoma californicum pluviale cocoon (Tachinid fly parasite)
Animation by April Randall, Orcas Island

References and Further Reading

Bell, K., Naranjo-Guevara, N., Santos, R., Meadow, R., & Bento, J. (2020). Predatory Earwigs are Attracted by Herbivore-Induced Plant Volatiles Linked with Plant Growth-Promoting Rhizobacteria. Insects11(5), 271. https://doi.org/10.3390/insects11050271

Clark, E. C. (1958). Ecology of the Polyhedroses of Tent Caterpillars. Ecology39(1), 132–139. https://doi.org/10.2307/1929975

Ciesla, W. , Ragenovich, I.R. 2008. Western Tent Caterpillar. USDA Forest Insect and Disease Leaflet 119. https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_042847.pdf

Cooper, Dawn & Cory, Jenny & Theilmann, David & Myers, Judith. (2003). Nucleopolyhedroviruses of forest and western tent caterpillars: Cross-infectivity and evidence for activation of latent virus in high-density field populations. Ecological Entomology. 28. 41 – 50. 10.1046/j.1365-2311.2003.00474.x.

Dahlhoff, V. Woods, A. and B. Larkin. 2019. The Western Tent Caterpillar, Malocosoma californicum pluviale. MPG North Field Notes. https://www.mpgnorth.com/field-notes/2019/08/western-tent-caterpillar-malacosoma-californicum-pluviale

Furniss RL, Carolin VM. 1977. Western forest insects. U.S. Department of Agriculture, Forest Service, Washington, D.C. Miscellaneous Publication 1339. 654 p.

Knight, G. A.; Lavigne, R. J.; and Pogue, M. G. 1991. “The Parasitoid Complex of Forest Tent Caterpillar,
Malacosoma Disstria (Lepidoptera: Lasiocampidae), in Eastern Wyoming Shelterbelts,” The Great Lakes Entomologist, vol 24 (4) Available at: https://scholar.valpo.edu/tgle/vol24/iss4/7

Rodstrom, R & Resources, Greenwood & Portland, Oregon & John, J & Brown, John. (2017). FOREST AND WESTERN TENT CATERPILLARS Insect Pest Management in Hybrid Poplars Series. 10.13140/RG.2.2.24262.37442.

Stehr, F.W. & E.F. Cook 1968. A revision of the genus Malacosoma Hubner in North America (Lepidoptera: Lasiocampidae): systematics, biology, immatures, and parasites. Bulletin of the United States National Museum, (276): 1-321. https://archive.org/details/bulletinunitedst2761968unit/page/n6/mode/1up?view=theater

Witter JA, Kuhlman HM. 1972. A review of the parasites and predators of tent caterpillars (Malacosoma spp.) in North America. Minnesota Agricultural Experiment Station. Technical Bulletin 289. 48 p.

Additional References***Updated 06.23.2022

Brennan, J.S., K.F. Higgins, J.R. Cordell, and V.A. Stamatiou. 2004. Juvenile Salmon Composition, Timing Distribution, and Diet in Marine Nearshore Waters of Central Puget Sound in 2001-2002. King County Department of Natural Resources and Parks, Seattle Wa. 164pp.

Brodeur, R. D., Mundy, B. C., Pearcy, W. G., & Wisseman, R. W. 1987. The neustonic fauna in coastal waters of the northeast Pacific: abundance, distribution, and utilization by juvenile salmonids. Oregon State University Publication ORESU-T-87-001.

Brodeur, R. D. (1989). Neustonic feeding by juvenile salmonids in coastal waters of the Northeast Pacific. Canadian Journal of Zoology67(8), 1995-2007.

Brodeur, R. D., Lorz, H. V., & Pearcy, W. G. (1987). Food habits and dietary variability of pelagic nekton off Oregon and Washington, 1979-1984. NOAA Technical Report NMFS 57.  U.S. Department of Commerce National Oceanic and Atmospheric Administration National Marine Fisheries Service.

Cheng L, Birch M. 2008. Insect flotsam: an unstudied marine resource. Ecol Entomol 3:87–97.

Cheng L. 1975. Marine pleuston: animals at the sea-air interface. Oceanogr Mar Biol Annu Rev. 13:181–212.

Cheng, L., M. C. Birch. 2009. Terrestrial insects at sea.  Journal of the Marine Biological Association of the United Kingdom57, 4, (995-997).

DNR TreeLink. Tenting in the Trees. 2012. WSU Extension Puget Sound Stewardship E-Newletter 5:4

Drake, V.A., D. R. Reynolds, Radar Entomology: Observing Insect Flight and Migration (CABI, Wallingford, UK, 2012).

Duffy, E.J., D.A. Beauchamp, R. Sweeting, R. Beamish, and J. Brennan. 2010. Ontogenetic diet shifts of juvenile Chinook salmon in nearshore and offshore habitats of Puget Sound. Transactions of the American Fisheries Society. 139:803-823. 

Glick P. 1939. The distribution of insects, spiders, and mites in the air. Washington D.C.: US Department of Agriculture. 

Green K., 2011. The transport of nutrients and energy into the Australian Snowy Mountains by migrating bogong moths Agrotis infusaAustral. Ecol. 36, 25–34.

Gutierrez, L. 2011. Terrestrial invertebrate prey for juvenile Chinook salmon: Abundance and environmental controls on an interior Alaskan river. MS Thesis, University of Alaska Fairbanks, Fairbanks, AK. 

Hardy AC, Cheng L. 1986. Studies in the distribution of insects by aerial currents. III. Insect drift over the sea. Ecol Entomol. 113:283–90.

Helm RR. 2021. The mysterious ecosystem at the ocean’s surface. Plos Biology. Apr;19(4):e3001046.

Holland RA, Wikelski M, Wilcove DS. How and why do insects migrate? Science. 2006 Aug 11;313(5788):794-6. doi: 10.1126/science.1127272. PMID: 16902129.

Hu G, Lim KS, Horvitz N, Clark SJ, Reynolds DR, Sapir N, Chapman JW. Mass seasonal bioflows of high-flying insect migrants. Science. 2016 Dec 23;354(6319):1584-1587. doi: 10.1126/science.aah4379. PMID: 28008067.

Landry J. S., Parrott L., Could the lateral transfer of nutrients by outbreaking insects lead to consequential landscape-scale effects? Ecosphere 7, e01265 (2016).

Locke, A., S. Corey. 1986. Terrestrial and freshwater invertebrates in the neuston of the Bay of Fundy, Canada. Canadian Journal of Zoology64(7): 1535-1541. https://doi.org/10.1139/z86-228

Myers, J. 2000. Population fluctuations of the western tent caterpillar in southwestern British Columbia. Popul Ecol 42, 231–241. https://doi.org/10.1007/PL00012002

Peterson, C. 2013. Where Are the Yellow-billed Cuckoos? https://www.birdnote.org/listen/shows/where-are-yellow-billed-cuckoos

Satterfield, Dara & Sillett, T & Chapman, Jason & Altizer, Sonia & Marra, Peter. 2020. Seasonal insect migrations: massive, influential, and overlooked. Frontiers in Ecology and the Environment. 18. 10.1002/fee.2217.

Zaitsev, Y. P. (1971). Marine neustonology.

Radar Love

Hello Everyone!  Meet my new bug friend, Radar Love ❤️  He must have crashed the wrong party.  Radar gone wrong!  I found him floating in our pool, in the midst of those raucous “dippers” (the Diplotaxis beetles).  Radar Love was so happy I didn’t let him drown, and even happier that I didn’t stick him with a pin and add him to the bug equivalent of a stamp collection.  We hung out together for a bit and I took some photos and video to remember him by.  Radar Love was released into the forest so he can make more of his kind.  

Odonteus obesus
Odonteus obesus

Odonteus obesus
Odonteus obesus
Odonteus obesus

Location:  San Juan Island

ID: Geotruipidae (Odonteus obsesus)

Special thanks to my friend, Michelle Sloan Bos and Tyler Hedlund for ID assistance with this.  I was rushing to get ready for my special spider outing.  More about that later.  For now, enjoy this rare and exciting  sighting of a most special little beetle that calls San Juan Island his home.  

More Info: https://bugguide.net/node/view/160586

Odonteus obesus

What are extrafloral nectaries?

Ants (Lasius sp.) on Big Leaf Maple Extra-Floral Nectary – May 17, 2022, San Juan Island, WA

When you study insects, or even birds for that matter, you start to understand you have to get to know plants a bit too.  It’s all connected.  

Plants (including trees and shrubs) provide food and shelter for many different species of animals.  Admittedly, I just don’t know a lot about the parts of plants, beyond things like a tree trunk, bark, limbs, branches, leaves, or stems or flowers, nuts, fruit.  The obvious parts.  

There are some not so obvious parts.  Like these extrafloral nectaries.  Huh? Sounds weird.  Keep reading. 

Extrafloral nectaries (EFN’s) are glands occurring on more than 2000 plant species in 64 families.  Extrafloral literally means outside of the flower. When we think of nectar, we usually think of little bees and hummingbirds flying around, visiting pretty flowers to sip nectar and in the process, pollinate all of our plants.  It’s just that plants are a bit more complex.  These glands are located in various places on plants (including trees and shrubs), and may be found on the laminae of leaves, petioles, rachids, bracts, stipules, pedices, fruit, etc.  (Mizell, 2019).  

These glandular secretions are a fascinating part of how plants attract and sustain a diverse, ecological community, providing sustenance for a multitude of species, including both pests and predators.  You can find ants, aphids, beetles (including ladybugs), bees, wasps, and possibly even birds utilizing this excretory faucet to sip what consists of mostly carbohydrate-rich sugar, but also comprised of a wide array of amino acids and other nutrients.  

Why are these important? Well, scientists are still trying to fully understand all of the diverse relationships around extra-floral nectaries. It is thought perhaps, beyond attracting organisms to a food source, they play a role in orchestrating a plant’s defense strategy against predators. They also are believed to provide a source of food and/or beneficial nutrients for various organisms during the off-season – when flowering and pollen sources are not available. They may also reduce conflict between ants and other pollinators by partitioning resources (Villamil & Stone, 2019).

Lasius sp. Ants at Extra-floral nectaries on Big Leaf Maple, 05.17.2022, San Juan Island, WA

Ant and aphid hanging out on extrafloral nectaries on Cherry Tree, San Juan Island, 05.17.2022

References

Bentley, B. L. (1977). Extrafloral nectaries and protection by pugnacious bodyguards. Annual Review of Ecology and Systematics8(1), 407-427.

Holopainen JK, Blande JD, Sorvari J. Functional Role of Extrafloral Nectar in Boreal Forest Ecosystems under Climate Change. Forests. 2020; 11(1):67. https://doi.org/10.3390/f11010067

Mizell, R. 2019. MANY PLANTS HAVE EXTRAFLORAL NECTARIES HELPFUL TO BENEFICIALS.  UF IFAS Extension Bulletin. https://edis.ifas.ufl.edu/publication/IN175

Villamil, N., Boege, K., & Stone, G. N. (2019). Testing the Distraction Hypothesis: Do extrafloral nectaries reduce ant-pollinator conflict?. The Journal of ecology107(3), 1377–1391. https://doi.org/10.1111/1365-2745.13135

No Clowning Around in the Pool Without a Life Jacket.

Yesterday I was the lifeguard. And, I had swimmers needing saving!

Hister Beetle (Genus Margarinotus I believe) – April 7, 2022 San Juan Island, WA

Here’s one of the species I used a piece of cardboard to rescue from drowning. This is a beetle in the family Histeridae, also known as a Clown Beetle. I told him no more clowning around without a life jacket. 🤣 Watch as it wrings its hindwings out, rolling them in under the leathery elytra (the outer wings).

I believe this beetle is in the genus Margarinotus. For ID beyond this, I’d need more time and a lot of patience. However, I can tell you I’ve learned some species of Hister beetles are associated with the nests of rodents, birds, and even ants and termites. They are pest predators, meaning they eat other insects at all life stages. They also are especially adept predators of fly eggs. You can often find them in leaf litter, dung, carrion, and under tree bark, or living in those ant mounds where they may be fed by ants, eat the leftovers the ants discard, or in some cases, they eat the ants!

Some other curious tidbits about these beetles include their acting ability. They play dead (Thanatosis) to deter predators. The word Hister is derived from Latin and means “Actor.”

Hister Beetle (I believe Margarinotus sp) – San Juan Island, WA

References:

Caterino, M. S. (2010). A review of California Margarinotus Marseul (Coleoptera: Histeridae: Histerinae: Histerini), with descriptions of two new species. The Coleopterists Bulletin64(1), 1-12. https://bioone.org/journals/The-Coleopterists-Bulletin/volume-64/issue-1/0010-065X-64.1.1/A-Review-of-California-Margarinotus-Marseul-Coleoptera–Histeridae/10.1649/0010-065X-64.1.1.pdf?casa_token=FFQE6VfrPhwAAAAA:6hS4kWWWX-lGeUPQFiU-7Dc2atg_nhsgP0almrxzvWjgwhxDLMShzekiAS7HWEKT5_AL2n4i

Wenzel, R. L. (1960). Three new histerid beetles from the Pacific Northwest, with records and synonymies of additional species (Coleoptera: Histeridae). https://www.biodiversitylibrary.org/page/2847194

Porch Light Bug Viewing – Who’s Watching Whom?

Some of you might cringe at the idea of standing below a porch light while an eclipse of moths (yep, that’s what a group of moths are called) are whirling and gyrating around your head. I find it fascinating, even as they hit at my face or hair, before bouncing back towards the light or disappearing off in the dark night.

Camera in hand, I wait for them to settle on the wood siding beneath the glow. Stealthily, I focus my lens to capture the delicate shimmer of scales and patterns, or eyes and antennae of my subject. Last night, I actually felt I was the one being observed.

This particular moth is in the genus Hypena. The species is Hypena decorata. It is a medium sized (15-18mm), somewhat drab moth. This species is sexually dimorphic – meaning the males look differently than the females. Males are slightly larger than females, with sooty brown forewings marked with two white spots near the apex or bottom edge of the wing.

Male Hypena decorata moth

Females of this species are more mottled in coloration, some with a purply hue. They also have a small patch of raised dark scales in the median area. More about distinguishing male and female specimens can be accessed here http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-hypeninae/hypena/hypena-decorata/

On occasion, there can be an odd form, like this one I found in August of 2019 https://buggingyoufromsanjuanisland.com/2019/08/22/hypena-decorata/

Food/host plants for Hypena decorata are nettles  (Urtica spp.) in the Urticaceae. These moths range from BC to Southern California. There appears to be two broods per year (April and August). Adults come to lights and can be found flying from April to September.

While this may appear to be merely another drab, ordinary moth, I want to show you the photos I took of the male and the nearby female last night. I missed it when I first went through my photos, but the second time around, it definitely appeared that the male moth was turning his head to watch me. Sort of like how Drago, my dragon lizard will do the same thing.

It’s a mysterious world, and much more rich when we recognize we aren’t the only ones that are aware. Some humans (I’m ashamed of researchers for this) do horrible things like cut off moths antennae to try and figure out how they fly (or can’t fly after being mutilated in this way). If we could only recognize they have a desire to live, find mates, food, and shelter – just like humans, maybe we would care more.

References and Further Reading

Bradley H. Dickerson, Zane N. Aldworth, Thomas L. Daniel; Control of moth flight posture is mediated by wing mechanosensory feedback. J Exp Biol 1 July 2014; 217 (13): 2301–2308. doi: https://doi.org/10.1242/jeb.103770

Bugguide https://bugguide.net/node/view/511337

Bugging You From San Juan Island (Hypena decorata) https://buggingyoufromsanjuanisland.com/2019/08/22/hypena-decorata/

Pacific Northwest Moths (Hypena decorata) http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-hypeninae/hypena/hypena-decorata/

Thompson, A. 2007. Mystery of Moth Flight Uncovered. LiveScience https://www.livescience.com/4338-mystery-moth-flight-uncovered.html

Author’s note – When it comes to experimenting on living beings, the aim of science shouldn’t always be to prove a hypothesis. Sometimes we need only to experience the extraordinary wonder of meeting the spirit within some of earth’s most unassuming characters. Be kind to those around you. Even the ones with scales and chitin.

Dolerus sp. Sawfly

I found another species of Sawfly in our above ground pool today. This one is entirely black. Size is approximately 7-8mm. This looks to be in the genus Dolerus. From what I’ve found about host plants, it looks like the larvae feed on most grasses and horsetail. Females deposit eggs into the plant tissue where they hatch and the larvae will feed for approximately one month before exiting and pupating overwinter in the surrounding soil. There is one generation (univoltine) per year and adults emerge in early spring. Adults are recorded as feeding on tree sap from Maple (Acer), Apple (Malus), and Pear (Pyrus). They also take nectar from Willow (Salix) flowers, and from Cherry and Plum (Prunus) flowers. This means they do provide some pollination activity.

Looks like WWU Biology Department is working on a web page for Sawfly identification, but it’s not up and running yet. You can find their link below and bookmark it to check out at a later date.

Dolerus sp. Sawfly
Dolerus sp. Sawfly – San Juan Island, WA 03.29.2022
Dolerus Sawfly – Specimen #2

References and Further Reading

Baine Q, Looney C (2019) Plant associations for three sawfly species (Hymenoptera, Tenthredinidae) in the Pacific Northwest. Journal of Hymenoptera Research 74: 27–33. https://doi.org/10.3897/jhr.74.46795

bugguide.net https://bugguide.net/node/view/13561

Looney C, Smith DR, Collman SJ, Langor DW, Peterson MA (2016) Sawflies (Hymenoptera, Symphyta) newly recorded from Washington State. Journal of Hymenoptera Research 49: 129–159. doi: 10.3897/JHR.49.7104

Sawfly GenUS https://idtools.org/id/sawfly/factsheet.php?name=17498

WWU Biology PNW Sawflies http://pnwsawflies.biol.wwu.edu/accounts/login/

Strawberry Muppets

Orthosia transparens – the Transparent Quaker Moth

I’d really love it if I could rename this moth. Strawberry muppet heart moth is what I’d call it. Check out the little heart-shaped markings on it’s wings.

Orthosia transparens – with heart mark on wing

Orthosia transparens is a medium sized (15-17mm) , brownish red Noctuid moth that flies in our region in early spring. The common name for the species is Transparent Quaker Moth.   Caterpillar food plants include salal (Gaultheria shallon), madrone (Arbutus menziesii), and rhododendron (Rhododendron macrophyllum). This species is native to the PNW region and not considered pests of economic significance. A map of the geographic distribution can be accessed here – http://mothphotographersgroup.msstate.edu/species.php?hodges=10479

Noctuidae is the family with the awful common name, “cutworm,” which leads folks to deem them evil little garden gremlins that should be stomped on or tossed out on the ground for birds to scavenge. Not all cutworms are bad, and certainly many more of us would embrace them if we knew they were going to turn out to be so cute.

I’m fine with a bit of herbivory on our salal, madrone, and rhododendrons. These little Strawberry Muppets are welcome to fly to my porch light any spring night.

Check out the gallery below for more photos and if you’re interested in reading more about this moth, check out my friend, Dan’s nice write up on his blog here – http://10000thingsofthepnw.com/2022/02/03/orthosia-transparens-transparent-quaker-moth/

Thanks for reading!

Is He Stuck or Just Sleeping?

I found this tiny bee who looked to be stuck to a thorn on my Bois D’Arc tree this afternoon. At first glance, I thought perhaps a March fly, and a dead one at that, but it turned out this is a most likely a “he” Nomad bee, and he wasn’t stuck at all, but just sleeping.

Nomad Bee – Stuck or Just Sleeping (March 26, 2022)

I learned something new today about bees that I did not know. My friend, Eric Eaton’s wife (link to Eric’s book about wasps in my Read More section) , shared with me that some bees will often sleep in this manner, attached to a substrate like this thorn or a twig, by their mandibles. Thanks Heidi! 🙂

Nomad Bee – Stuck or Just Sleeping (March 26, 2022)

Nomad Bee – Stuck or Just Sleeping (March 26, 2022)
Nomad Bee (March 26, 2022)

My bee was definitely gripping the end of the thorn with its mandibles. Before I found out my bee was only napping, I wasn’t certain what was going on. I worried maybe the bee had fallen victim to some weird fungus and was now locked in a death vise. Worries unfounded! The little bee released his grip as I was about to clip the end of the twig (with bee attached) and take it into the house to view under the microscope.

Nomad bees are pretty cool. They are cuckoo bees, cleptoparasites of other bees (usually Andrena bees or Melitta bees) and target the nest provisions gathered by the host bees for their own young. Nomad bees will find the nests of host bees using olfactory and visual cues. The fertilized female will lay her eggs in these nests, where her offspring will develop after devouring the offspring of the host bee, and eating the food the host parent had provisioned.

Nomad Bee (March 26, 2022)

Check out the video footage of this little bee as he woke up this afternoon and read more about Nomad bees in the attached links in my Read More section.

Read More About Nomad Bees Here

  1. Bugguide.net – Nomada https://bugguide.net/node/view/5211
  2. Alexander, B. A. 1994. Species-groups and cladistic analysis of the cleptoparasitic bee genus Nomada (Hymenoptera: Apoidea). University of Kansas Science Bulletin 55: 175-238. (Full Text)
  3. Eaton, Eric. 2021. Wasps: The Astonishing Diversity of a Misunderstood Insect. Princeton University Press. https://press.princeton.edu/books/hardcover/9780691211428/wasps
  4. Rankin, C. 2021. Introducing the Nomad Bees. Natural History Society of Northumbria. https://www.nhsn.org.uk/nomad-bees/

Thanks for reading!

Cynthia Brast is an independent entomologist living on San Juan Island. Check out her YouTube Channel, Bugging You From San Juan Island to see more amazing 6 and 8-legged creatures found in the San Juans. https://www.youtube.com/user/buggingyoufromsji/featured

A Little Weevil House

Key Words: masting, Curculio, Quercus, mast seeding, acorn weevil, diapause

I picked up these acorns (Quercus sp.) when I visited my folks recently in Texas. They have several oak trees on their property and there was an abundance of acorns all over the ground this year, so I brought a few home with me in a ziplock bag. I like acorns. My mom used to draw little faces on them and I had acorn “people” to play with when I was a child.

Acorn “person”

I also found a very cool bug under one of those oak trees while I was there. This strange looking creature is one of the Nut and Acorn Weevils (Curculio sp). It has an extremely long snout. When you find out how this weevil uses it to DRILL, you may be amazed. The adult female weevil will use this drill on her very long snout to make a hole in those acorns!

Nut and Acorn Weevil (Curculio sp).
Nut and Acorn Weevil (Curculio sp).
Nut and Acorn Weevil (Curculio sp).

Keep reading. It really is amazing.

A female weevil will make a hole in the acorn so she can put her eggs inside it!

Hole drilled by Nut and Acorn Weevil

Because I like word games, I thought I’d point out to you that rearranging the letters in the word weevil will make the words “we live?” Well, those eggs hatch into baby weevils who LIVE in a little house that is an acorn (and sometimes in other nuts too). Some folks call them grubs or worms. They are actually the larvae of the adult weevil mom who selected the acorn for her nursery.

If you are assessing this situation from an agricultural perspective (say that nut is a pecan), invested in harvesting a profitable crop, you might be feeling very worried. Sometimes the worry may indeed be justified, but in many cases, like with these acorns, the tree has evolved a strategy to deal with occasional waves of weevils and other insects we consider pests. In actuality, they are just utilizing the resources of the tree like we do when WE (the humans) eat the nut or fruit.

Larvae of Nut and Acorn Weevil (Curculio sp).

I’m going to name the trees’ strategy of dealing with this bug FEAR NO WEEVIL. However, the actual scientific moniker for this strategy (and it applies to other pests and adverse weather stressors as well) is MASTING. The word mast has been used since way back in the Middle Ages to refer to the acorns and seeds of forest trees that drop and accumulate on the ground. It comes from Old English, mæst. Essentially, masting is an ecological term referring to the highly variable and often synchronized periodic cycles of fruiting/seeding in the reproductive processes of trees (both forest and fruit trees).

How is it a strategy for circumventing the deleterious affects of pests? Well, the idea is that in some years, bumper crops of nuts and seeds are produced in order to satiate the predators, so some are left to germinate and continue new generations. In this particular case, you could think of it as the oak trees sacrificing some of their offspring to the weevil gods. When there are more acorns than there are adult female weevils, some of those acorns will escape the weevil drill and makeover into little bug nurseries.

In reality, this relationship is much more complicated. In some cases, acorns parasitized by only a few weevil larvae will germinate, while those acorns with many larvae will not. The trees’ bumper crops of seeds and nuts will also cycle with years of low production, where resources are scarce for the weevil (and other organisms). Nature is incredibly dynamic though. Studies show some species of weevils have adapted a counter mechanism to circumvent the trees’ strategy of masting. It’s called prolonged diapause. This means these weevils are able to sleep longer (more than one year) as they develop in order to synchronize adult emergence with years when the trees’ seed/nut production is high.

If you are interested in reading more about the history and MYSTERY of masting, I encourage you to delve into the literature I’ve listed in the references below. It’s quite fascinating – especially going back in history to the link between masting and pannage. Way more than I can cover here. Check it out.

References

Baldwin, M. 2021. Pigging out in the forest: the Common of Mast (Pannage) in Britain https://www.wildlifeonline.me.uk/blog/post/pigging-out-in-the-forest-the-common-of-mast-in-britain

Bugguide 2021. Curculio. https://bugguide.net/node/view/6682

Higaki M (2016) Prolonged diapause and seed predation by the acorn weevil, Curculio robustus, in relation to masting of the deciduous oak Quercus acutissima. Entomol Exp Appl 159:338–346. https://doi.org/10.1111/eea.12444

Jefferson, R. 2006. Why Are More Acorns Falling? Excessive Drops of Nuts from Oak Trees Is Part of Normal ‘Mast Year’ Phenomenon. Scientific Times. https://www.sciencetimes.com/articles/33795/20211006/why-more-acorns-falling-excessive-drops-nuts-oak-trees-part.htm and https://youtu.be/EQ748TZcuqs

Jesse, L. No date. The dark side of collecting acorns. Plant and Insect Diagnostic Clinic. Iowa State University Extension and Outreach. https://www.extension.iastate.edu/news/2007/sep/072107.htm

Koenig WD. 2021 A brief history of masting research. Phil. Trans. R. Soc. B 376: 20200423. https://doi.org/10.1098/rstb.2020.0423 Koenig, W. D., & Knops, J. M. H. (2005). The Mystery of Masting in Trees: Some trees reproduce synchronously over large areas, with widespread ecological effects, but how and why? American Scientist93(4), 340–347. http://www.jstor.org/stable/27858609

Araneus diadematus, My Cross Orb Weaver friend named “Louisa.”

I first spotted this beauty on October 1, 2021 while I was taking a walk along our road on San Juan Island. There was a cluster of sun loving mullein (Verbascum thapsus) mixed with one or two thistles (probably Canada thistle) growing along the road. The glistening silk threads woven between them drew me over to investigate. There were several Cross Orb Weavers sharing the space here, but one of these was not like the other. The spider that caught my attention was quite a bit darker than the others. Describing it as brown just doesn’t do it justice. Brown sounds much too plain. She was a lovely brunette amongst a few redheads!

~ After you’re done reading, come back and check out this link to learn more about pigmentation in arachnids – https://www.bio.fsu.edu/~miller/Spider%20photos/spider_literature/color%20in%20spiders%20papers/Oxford_Gillespie_20xx.pdf

Since I often enjoy walking on our road on sunny days, I started looking for her when I passed her home – the Mullein “apartments.” It wasn’t just the spiders enjoying the sunny housing complex, but these units housed a few other species as well. I found some Stilt Bugs (Neoneides sp.) and some Pentatomidae hiding in the fuzzy star shaped trichomes (little hairs) of the Mullein leaves.

Now that autumn has ushered in falling leaves, falling temperatures, and a good bit of rain, I thought of my friend Louisa, the Orb Weaver out in the cold. Had she managed to find a sheltered spot to survive the recent storms? Several times over the past two weeks I’ve looked for her, but she was just gone. Since the lifespan for this species is only a year or less, I suspected she’d reached her end with our last dip in temperatures, gusty winds, and precipitation. I held out a tiny bit of hope though. Just a bit!

Today (November 6, 2021), my husband and I walked our road. It was sprinkling and the precipitation was cold. When we got down to the point on the road to turn around, shortening our walk to just the point where the old cabin used to be, I asked him to wait one second while I looked one more time at that patch of Mullein and the drying stand of thistles.

As I bent down to look closely, I saw a single strand of silk. Examining the attachment and following closely, it led me to Louisa. She was tucked under the dried nodding inflorescence of the thistle. Once a purply-pink sugar treat for pollinators, the now nodding blooms have been repurposed into a thatch roof to keep this little spider dry.

I’ve thought about relocating her so the county doesn’t mow her when they scalp the roadside vegetation. It is bound to happen at some point. For now, I’m going to leave her be, and just keep a close eye on her. Maybe I’ll make a sign! Be Nice to Spiders. ❤️ Louisa lives here!

Fun Fact! Did you know that 25% of the diet of Orb Weaver spiderlings is pollen? Check it out. Article linked in my list of sources below.

Araneus diadematus (Cross Orb Weaver) October 1, 2021 – San Juan Island, WA

Araneus diadematus (Cross Orb Weaver) October 1, 2021 – San Juan Island, WA

Araneus diadematus (Cross Orb Weaver) October 1, 2021 – San Juan Island, WA

Araneus diadematus (Cross Orb Weaver) October 13, 2021 – San Juan Island, WA
Araneus diadematus (Cross Orb Weaver) October 16, 2021 – San Juan Island, WA

This is “Louisa,” the Land Bank Orb Weaver Spider. She lives on a Mullein plant alongside the road. I’ve been watching her since October 1, 2021. Hoping she will not become a casualty of San Juan County’s pre-winter roadside mowing. She’s also an expecting mom!

This is “Louisa,” the Land Bank Orb Weaver Spider. She lives on a Mullein plant alongside the road. I’ve been watching her since October 1, 2021. Hoping she will not become a casualty of San Juan County’s pre-winter roadside mowing. She’s also an expecting mom!

Araneus diadematus (Cross Orb Weaver) November 6, 2021 – San Juan Island, WA
Araneus diadematus (Cross Orb Weaver) November 6, 2021 – San Juan Island, WA
Araneus diadematus (Cross Orb Weaver) November 6, 2021 – San Juan Island, WA

References and further Reading –

Eggs B, Sanders D (2013) Herbivory in Spiders: The Importance of Pollen for Orb-Weavers. PLoS ONE 8(11): e82637. https://doi.org/10.1371/journal.pone.0082637

Gucker, Corey L. 2008. Verbascum thapsus. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://www.fs.fed.us/database/feis/plants/forb/vertha/all.html [2021, November 6]. 

Horton DR, Lewis TM (2003) Numbers and types of arthropods overwintering on common mullein, Verbacsum thapsus L. (Scrophulariacae), in a central Washington fruit-growing region. Journal of the Entomology Society of British Columbia 100, 79–87.

Oxford, Geoff & Gillespie, Rosemary. (1998). Evolution and ecology of spider coloration. Annual review of entomology. 43. 619-43. 10.1146/annurev.ento.43.1.619.

Riaz, Muhammad, Zia-Ul-Haq, Muhammad and Jaafar, Hawa Z.E.Common mullein, pharmacological and chemical aspects. Revista Brasileira de Farmacognosia [online]. 2013, v. 23, n. 6 [Accessed 6 November 2021] , pp. 948-959. Available from: <https://doi.org/10.1590/S0102-695X2013000600012&gt;. ISSN 1981-528X. https://doi.org/10.1590/S0102-695X2013000600012.

Turker AU, Gurel E. Common mullein (Verbascum thapsus L.): recent advances in research. Phytother Res. 2005 Sep;19(9):733-9. doi: 10.1002/ptr.1653. PMID: 16222647. https://onlinelibrary.wiley.com/doi/10.1002/ptr.1653

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