Bugging You From San Juan Island

Canary thorn moth, (Neoterpes trianguliferata)

Posted on April 28, 2025 by "BUGGING" YOU FROM San Juan Island Leave a comment

I found the most beautiful creature at my moth light this morning. It is the Canary Thorn Moth (Neoterpes trianguliferata ). I was surprised to see anything there given the drop in temperatures we’ve had the past few days. After a few photos, I got too close and he flew out of the open barn area into some grass, struggling a bit in the wind, so I was able to carefully coax him back into an egg carton to shelter the day back undercover and out of the rain.

If you’re wondering about the egg carton, I use these in my moth light set up to give the moths a secure place to hide when they settle down under the light for the night. The egg cartons are in a 5 gallon bucket. I have the “low end” set up, so no major investments in equipment. Anyone could do this at home. It’s fun to “moth” and see what species live around us. If you’re interested, shoot me an email and I’ll coach you on getting set up yourself. For the record, all of my specimens are photographed with respect and care, and allowed to live free. I do not take specimens for pinning. I definitely believe they are here to be admired in the wild, not in a glass case.

More about this species:

Neoterpes trianguliferata is a species of Geometrid moth that ranges from southern British Columbia to southwestern Alberta, south to Colorado, Utah, and California. The hostplants for larvae (the caterpillars) are Currants and Gooseberry (Ribes). I’ve linked information for some of the native host plants below in the reference section.

Larvae are twig mimics. Pupae sleep through the winter wrapped in a leaf, another reason to “leave the leaves” and refrain from burning or bagging and discarding the leaves around your home. You could inadvertently impact overwintering species like these and others. Adults are approximately 14-20mm (forewing length). You will see adults in flight between April-June in our area. From what I have been able to find as to the etymological meaning of the name, Neoterpes may translate to “new delight” and trianguliferata refers to the triangle-shaped markings on the forewings. It was indeed a delight to see this beauty today! A bit of sunshine on a rainy spring day.

Canary thorn moth (Neoterpes trianguliferata)

References

Bressette, Dana Kelley. no date. Coast Black Gooseberry, Ribes divaricatum. Native Plants PNW. https://nativeplantspnw.com/coast-black-gooseberry-ribes-divaricatum/

Bressette, Dana Kelley. no date. Red Flowering Currant, Ribes sanguineum. Native Plants PNW. https://nativeplantspnw.com/red-flowering-currant-ribes-sanguineum/

Bugguide.net. 2023. Species Neoterpes trianguliferata – Hodges#6860. Bugguide. Iowa State University. https://bugguide.net/node/view/114007

Moth Photographers Group. Neoterpes trianguliferata (Packard, 1871). Mississippi State University. https://mothphotographersgroup.msstate.edu/species.php?hodges=6860

Nelson, Dan. 2021. Neoterpes trianguliferata. 10,000 THINGS OF THE PACIFIC NORTHWEST
Adventures of a Recreational Naturalist. http://10000thingsofthepnw.com/2021/08/08/neoterpes-trianguliferata/

Odonteus obesus, the Geo-trooper

Posted on April 28, 2025 by "BUGGING" YOU FROM San Juan Island Leave a comment

This is a post about one of the most unusual beetles I’ve ever found on San Juan Island. The species is Odonteus obesus. I’m hoping to attract a male specimen to my bug light after finding this female over the weekend, but haven’t had any luck yet. A few years ago, I found a male though. They are simply incredible, beautiful and weird all at once… like finding a unicorn in the forest. Literally! The male of this species has a sharply pointed unicorn horn that protrudes from the front of its head. If you are curious to see a male specimen, check out an earlier blog post I wrote about them here – https://buggingyoufromsanjuanisland.com/tag/odonteus-obesus/

These beetles are in the family Geotrupidae. “Geo” from Greek, meaning earth, and “trypetes” or “trupes” which means to bore or drill. In Europe, these beetles are referred to as dor beetles. “Dor” because they hum. Check out the etymology I’ve copied for you below for the word Dor.

Greek “dor” (δορ):. Primarily used in Proto-Indo-European languages, “dor” and “dorn” meant “bee,” “hornet,” or “drone,” as explained by Wiktionary. It’s related to the Middle English “dorre” and Old English “dora,” also meaning “humming insect,”.
English “dor” or “dor beetle”:

This term, derived from the Old English word, is used to describe a variety of buzzing insects, including some dung beetles. According to Collins Dictionary.

Geotrupid beetles live in the earth in burrows they excavate that can be up to 4 feet deep, often in material composed of dead leaves, cow or horse dung, or humus. We don’t have any horse or cow dung in our yard, so I’m guessing the decaying forest leaf litter is a suitable substrate for them or perhaps they are incorporating deer or the dung of other wildlife (fox, raccoon, or rodents) for use.

Why are Geotrupid beetles (and other dung beetles ) extremely beneficial? They are a source of food for other wildlife that eat them, but perhaps even more important for the role they play in improving soils by adding nutrients and removing animal waste. The beetle’s burrowing nature helps build healthy soil by incorporating organic matter, resulting in increased soil friability (it isn’t as clumpy), improved soil aeration, as well as improved water-holding capacity.

Additionally, these, and other species of dung beetles, have been found to be effective biological control agents for gastrointestinal parasites of livestock. In agricultural areas, they “clean” the pasture by removing manure or decomposing material as they burrow into the earth https://attra.ncat.org/publication/dung-beetle-benefits-in-the-pasture-ecosystem/.

Unfortunately, the increasing dependence of livestock producers on veterinary anthelmintic medications is threatening populations of nature’s best (and free) helpers. Many of the worming medications (like Ivermectin) given to livestock, pass through into the dung and then kill off the dung beetles when they feed. The result is an increased reliance on veterinary medications to control livestock pests and parasites and decreased pasture health because there is no beetle to break down the animal dung. As the pasture is littered with scattered dung, it becomes harder for the livestock to feed because they will avoid areas contaminated with dung.

To learn more about this species and other dung beetles, please check out the linked references below.

Thanks for reading!

Odonteus obesus

References and Further Reading

Brast, Cynthia. 2022. Radar love. Odonteus obesus. Bugging You From San Juan Island. https://buggingyoufromsanjuanisland.com/tag/odonteus-obesus/

Bugguide.net. 2023. Geotrupidae Earth-Boring Scarab Beetles. Iowa State University. https://bugguide.net/node/view/6810

Entomologist.net. No Date. Beetles Dor Beetle (Geotrupes stercorarius) https://entomologist.net/beetles/62-geotrupes-stercorarius.html

Jameson, Mary Liz. 2005. Geotrupidae. Generic Guide to New World Scarab Beetles. UNL State Museum. https://unsm-ento.unl.edu/Guide/Scarabaeoidea/Geotrupidae/Geotrupidae-Overview/GeotrupidaeO.html

Thomas, Michelle. 2001, and Rodriguez, O. 2020. Dung Beetle Benefits in the Pasture Ecosystem. ATTRA Sustainable Agriculture. National Center for Appropriate Technology. https://attra.ncat.org/publication/dung-beetle-benefits-in-the-pasture-ecosystem/

Counting Bugs: What’s at the light in the night? April 20, 2025

Posted on April 21, 2025 by "BUGGING" YOU FROM San Juan Island Leave a comment

Here’s a quick rundown of what I spied at my bug light when I checked this morning. I did move the bucket and light to a new location across from our house in our open air barn.

There were nine species of moths (31 individuals), two species of Coleoptera (beetles), and one wasp that I believe is Ophion sp.

Moths:

Egira perlubens = 1

Egira (either E. simplex or E. crucialis) = 3

Egira rubrica = 1

Orthosia transparens = 5

Orthosia hibisci = 8

Orthosia praeses = 8

Feralia comstocki = 2

Eupithecia graefii = 2

Melanolophia imitata = 1

Beetles:

Diplotaxis sp. = 2

Strophosoma melanogrammum = 1

Wasps:

Ophion sp. = 1

If I may, I’d like to leave you with something to consider. When you rake your leaves and clean your yard – especially if you are burning, chipping, or bagging and removing all those things that fall onto the ground, you are eliminating habitat for native species. If you can refrain the urge to spring clean around your property, you can help support life.

These may be somewhat drab colored moths and you may not even like them, but they sustain other organisms, including plants, because moths are also nighttime pollinators. Each species has a niche, and a role in the ecosystem (and ultimately the food web).

Please take note of nature around you. It’s actually beautiful and mysterious. Whether you like it or not though, nature is life. Nature matters. Little things like leaving the leaves can make a difference. Care.

Thanks for reading.

Moth Light/Bug Tally for 04.19.2025

Posted on April 20, 2025 by "BUGGING" YOU FROM San Juan Island One comment

Here are some photos of specimens found from my light trap set up last night. The official tally is listed here as well.

Light Trap Count – 4.19.2025
37 specimens. Moths from 8 different Genera; 11 species. 1 Wasp species, 2 Beetle species, and 1 spider species.

Moths:
Orthosia transparens – 3
Orthosia hibisci – 9
Orthosia praeses – 7
Venusia pearsalli – 2
Eupithecia graefii – 1
Egira rubrica -1
Egira simplex- 1
Egira unknown (possibly one of the other two listed here) – 1
Feralia – 3
Perizoma curvilinea – 2
Behrensia conchiformis – 1
Emmelina mondactyla – 1

Beetles from 2 families (Carabidae and Curculionidae)

Carabidae: Diplotaxis sp. – 3

Curculionidae: Strophosoma melanogrammum – 3

Spider:
Philodromus dispar (male) – 1

Wasp:
Ophion sp. – 1

Location: San Juan Island, WA

A spider with a hump

Posted on April 20, 2025 by "BUGGING" YOU FROM San Juan Island One comment

I thought I’d take a moment to profile a new-to-me spider found in my kitchen last week. This one was awfully small at about 4-5 mm, and threading the beginning of a web from my kitchen counter to the dishwasher. I needed a cup for my morning coffee, and the kitchen (at least our kitchen) is not a safe place for a free roaming spider. Not with Herman the Persian and his furry duster of a tail.

I collected her gently, took these photos, and released her outdoors on one of my mint plants. My efforts at ID-ing this unusual beauty, beyond family Tetragnathidae and possibly genus (Metellina) necessitated sending the photos to my friend, Rod Crawford at the Burke Museum, for further help.

Rod quickly wrote back with, “Metellina mimetoides, only local species in genus with humped abdomen.”

Metellina mimetoides is a species native to North America and found along the Pacific Coast from Southern California through Northern Washington. I would say these are not particularly abundant though. This was my first ever sighting of one on San Juan Island, WA.

And here she is!

Fantastic Fly Friday

Posted on April 11, 2025 by "BUGGING" YOU FROM San Juan Island Leave a comment

I thought I’d write up a short post about all the wonderful flies (and a few others) pollinating our plum trees in this cool spring weather. Why feature the flies? Well, for starters, the plum tree blossoms are white and flies love the color white. Another reason to feature the flies is because they are under-recognized and under appreciated, but very important pollinators. Some fly larvae even serve as pest predators, eating aphids. Others, like the tachinid fly below, use caterpillars that defoliate trees as hosts for their larvae to develop. Flies are also awesome because they do not sting! Some even “dance!” My favorite fly hasn’t shown up yet. It’s a Conopid Fly. More about that one later though…

Tachinid Fly (Epalpus signifier)

This past week in the media, there have been so many posts about the decline in honey bees. While there are some (unwanted) honey bees showing up on days when the temperatures climb above 50 degrees, honey bees aren’t active if it is cooler. Flies, on the other hand, are quite busy at work pollinating and do just fine when it might only be 40 outside. Flies are awesome! They need our support and appreciation.

I’d like to add (and I do know something about this because of my entomology background), that honey bees are just not necessary on San Juan Island. In fact, they might even be a very bad thing. They showed up at our plum tree as the temperature warmed up the other day, and as they arrived in increasing numbers, they kicked off ALL of the native pollinators that I had been observing. 😦

For honey bees to fly out of the hive and forage, they need temperatures above 50 degrees. In my experience keeping bees (as part of my graduate school work), they typically do not survive well on the island unless they are fed supplemental sugar water. Think about the ecological footprint of growing sugar to feed the bees!

Feeding honey bees attracts (and supports) the buildup of yellow jacket populations which are attracted to honey bee hive resources (including eating the honey bee brood developing in the hive), and honey bees also bring pests and pathogens that impact native bees (especially bumble bees). One more thing! If you are growing tomatoes, bumble bees are your pollinators, not honey bees.

I hope you will read and consider this recent study published about how honey bees were negatively impacting native pollinators on Giannutri Island in Italy. They were causing a decline in the populations of wild bees. In fact, the study cited an “alarming 80% decline in wild bee abundance over 4 years” (Pasquali et al. 2025). You can access this study to read it yourself here: https://www.cell.com/current-biology/pdfExtended/S0960-9822(25)00262-3

Enjoy the gallery of the native pollinators that I was fortunate to photograph and be able to share. Be a fly fan! Be a native bee fan! Learn about our unseen, but important night time pollinators (moths), and PLEASE LEAVE THE HONEY PIGS for the mainland industrial farm operations.

Golden Dung Fly (*Scathophaga stercoraria*)

(*Melanostoma mellinum* )Variable Duskyface Fly

Sericomyia chalcopyga Western Pond Fly

Bibionid Fly (Bibio sp.) and Hybotidae Dance Fly (Bicellaria sp.)

(Melanostoma mellinum) Variable Duskyface Fly

References

Anderson, H. L. D. (2024). Nocturnal moth communities and potential pollinators of berry agroecosystems in British Columbia (T). University of British Columbia. Retrieved from https://open.library.ubc.ca/collections/ubctheses/24/items/1.0447737

KEARNS, C. A. 2001. North American dipteran pollinators: assessing their value and conservation status. Conservation Ecology 5(1): 5. [online] URL: http://www.consecol.org/vol5/iss1/art5/

Pasquali, Lorenzo & Bruschini, Claudia & Benetello, Fulvia & Bonifacino, Marco & Giannini, Francesca & Monterastelli, Elisa & Penco, Marco & Salvati, Vania & Simbula, Giulia & Skowron Volponi, Marta & Smargiassi, Stefania & van Tongeren, Elia & Vicari, Giorgio & Cini, Alessandro & Dapporto, Leonardo. (2025). Island-Wide Removal of Honey Bees Reveals Exploitative Trophic Competition with Strongly Declining Wild Bee Populations. 10.2139/ssrn.5081459. https://www.sciencedirect.com/science/article/pii/S0960982225002623#:~:text=Article-,Island%2Dwide%20removal%20of%20honeybees%20reveals%20exploitative%20trophic%20competition,strongly%20declining%20wild%20bee%20populations

Ssymank, A., Kearns, Bonn & Carol. Flies – Pollinators on two wings. The Diptera Site. https://diptera.myspecies.info/diptera/content/flies-–pollinators-two-wings

Diptera

April 7, 2025 – A Million or More

Posted on April 7, 2025 by "BUGGING" YOU FROM San Juan Island Leave a comment

I woke up this morning feeling like my head is going to explode. Migraine sufferers will identify. The throbbing continues, regardless of whatever you might throw at it. I managed to get little Olivia to the vet by 09:40 to get her spay stitches out and our vet cleaned her ears. She had a lot of wax buildup and came home with some antibiotic ear drops to ward off any potential infection that might be developing. Olivia is our latest rescue cat. She’s a sweet little Tortie Persian. Age 2. It’s been a delight to have her sharing our space and she’s made fast friends with our other two resident kitties (Herman and Nimbus).

Olivia the cat

After I got back home from town, I went back outside to walk around the yard a bit hoping the cool air would calm down my headache. I wandered over to look in the above ground pools we have for water catchment. One is in the shade and the other is in the sun. It’s pretty cool how they each have their own mini ecosystems going on.

Hypogastrura sp. Springtails and a millipede raft

The shaded pool was the active one today. It was literally covered with a million or more of these teeny aquatic springtails. Initially, I believed the species to be Podura aquatica in the family Poduridae, but someone has suggested a different family (Hypogastruridae) altogether as a possibility. I may have to revisit my ID. Springtails or Collembola are tiny hexapods. The ones in my photo looked to be approx. 1mm in size. The blue-ish ones you see in the photo are mature specimens and the pinkish/orange ones are juveniles. I believe this could be a mating aggregation (Sánchez-García et. al, 2018). *** note *** Updating ID to family Hypogastruidae (Genus Hypogastrura) after looking at these under a microscope and seeing they have a reduced furcula (the little appendage on the back end that helps them jump).

There were so many of these that it looked as if the surface of the pool had been sprinkled with pepper. I found some in a water dish I had on the ground that were easier to photograph. There were a few rafting on a poor little millipede that somehow ended up in the water. It was still alive, so I fished it out and moved it to a nice damp spot in the soil.

An aggregation of tiny springtails (Hypogastrura sp.)

Hypogastrura sp. springtails

Some species of springtails are semi aquatic, living in fresh water. Others are common in soil and leaf litter where they influence decomposition processes and nutrient availability. Some are arboreal and are abundant in rain forest canopies. There are even springtails living successfully in polar regions (Hopkin,1997 ; Sanchez-Garcia et al, 2018).

Springtails hanging out with a deceased backswimmer (Notonectidae)

Raft of Hypogastrura sp. springtails photographed March 27, 2025 – San Juan Island, WA

Check out the reference list I have attached below for further reading. Some of these are really interesting!

References

Ádám Egri, György Kriska. 2019. How does the water springtail optically locate suitable habitats? Spectral sensitivity of phototaxis and polarotaxis in Podura aquatica. J Exp Biol 222 (9): jeb199760. https://journals.biologists.com/jeb/article/222/9/jeb199760/688/How-does-the-water-springtail-optically-locate

Bellini, B. C., Weiner, W. M., & Winck, B. R. 2023. Systematics, Ecology and Taxonomy of Collembola: Introduction to the Special Issue. Diversity, 15(2), 221. https://doi.org/10.3390/d15020221

Bugguide. 2025. Hypogastrura.

Childs, G. H. 1915. Some observations on the life history of the water springtail (Podura aquatica – 1758). MSc thesis, University of Minnesota, Minneapolis.

Heckman, C. W. 2018. Ecological Strategies of Aquatic Insects. Boca Raton: CRC Press, Taylor & Francis Group.

Hopkin SP. 1997. Biology of the Springtails (Insecta: Collembola). New York: Oxford Univ. Press.

Möllerke A, Brasse G, Bello J, Vidal DM, Dettner K, Zettel J, Berg MP, Scheu S, Leinaas HP, Schulz S. 2024. The unique epicuticular chemistry of Collembola – A cross-species analysis. iScience. 27(8):110416. doi: 10.1016/j.isci.2024.110416. PMID: 39139403; PMCID: PMC11321324.

Noble-Nesbitt, J. 1963. A site of water and ionic exchange with the medium in Podura aquatica L. (Collembola, Isotomidae). J. Exp. Biol. 40, 701-711.

Ortega-Jimenez VM, Challita EJ, Kim B, Ko H, Gwon M, Koh JS, Bhamla MS. 2022. Directional takeoff, aerial righting, and adhesion landing of semiaquatic springtails. Proc Natl Acad Sci U S A. 119(46):e2211283119. doi: 10.1073/pnas.2211283119. Epub 2022 Nov 7. PMID: 36343251; PMCID: PMC9674249.

Silje Marie Kristiansen, Katrine Borgå, Jan Thomas Rundberget, Hans Petter Leinaas, Effects on Life‐History Traits of Hypogastrura viatica (Collembola) Exposed to Imidacloprid Through Soil or Diet, Environmental Toxicology and Chemistry, Volume 40, Issue 11, 1 November 2021, Pages 3111–3122, https://doi.org/10.1002/etc.5187

Rusek, J. 1998. Biodiversity of Collembola and their functional role in the ecosystem. Biodiv. Conserv. 7, 1207-1219. https://doi.org/10.1023/A:1008887817883

Sánchez-García A, Peñalver E, Delclòs X, Engel MS. 2018. Mating and aggregative behaviors among basal hexapods in the Early Cretaceous. PLoS ONE 13(2): e0191669. https://doi.org/10.1371/journal.pone.0191669

Schulz, S., Messer, C., & Dettner, K. 1997. Poduran, an unusual tetraterpene from the springtail Podura aquatica. Tetrahedron Letters, 38(12), 2077–2080. doi:10.1016/s0040-4039(97)00341-9

Silje Marie Kristiansen, Katrine Borgå, Jan Thomas Rundberget, Hans Petter Leinaas, 2021. Effects on Life‐History Traits of Hypogastrura viatica (Collembola) Exposed to Imidacloprid Through Soil or Diet, Environmental Toxicology and Chemistry, Volume 40, Issue 11, Pages 3111–3122, https://doi.org/10.1002/etc.5187

Yule, Catherine & Yong, Hoi Sen. (2012). 33. Collembola. https://www.researchgate.net/publication/233727118_33_Collembola

April 6, 2025 – A Wet Spring Day

Posted on April 6, 2025 by "BUGGING" YOU FROM San Juan Island One comment

Last night, I did manage to get my moth light working again and set things up to see what I might find this morning. While I didn’t really want to get out of bed at 7:30, keeping a routine is important to me. I find it tremendously helpful in managing the ups and downs of one’s mental perspective. You’ll have to bear with me a bit though. I will get to the moths, but have to vent about something that upset me. One of my three cats was chattering at the sliding door when I walked towards the kitchen. I looked out to see what he was watching, and there was a little bird on the ground, obviously suffering from some unfortunate injury (most likely from our neighbor’s free roaming cat). That made me feel sad and angry and it wasn’t the best start to my day.

Don’t get me wrong. I love cats, but I don’t agree that it is OK to allow your feline friend to maim and kill wildlife. I do take my kitties outside with me into our fenced area for supervised recess, but I DO NOT ever leave my cats out alone and certainly do not allow the killing of wildlife. Not even bugs. Drago the lizard may get away with bug murder on occasion, but his impact is quite minor compared to the magnitude of damage done by free roaming cats when it comes to decimating wildlife.

We need to get people to change and become more responsible pet owners. If you disagree with me on this, I might add that I also saw someone’s cat was literally ripped apart on their front porch by two unleashed huskies in Friday Harbor yesterday. That also makes me sad and angry. I blame the cat owner AND the dog owner. It was senseless and preventable.

I think humans need a license to own a pet. We also need ANIMAL CONTROL in San Juan County. There is none and these huskies have been loose and killed cats before. However, if the cat owner was allowing the cat to roam outside unsupervised and unprotected, that’s another layer to the incident. What if someone had left their baby in a stroller long enough to run inside for keys, a purse, etc.? No one should own a husky as a pet. They are notorious for getting loose and killing things. But humans are not all that smart are they?

I did go out to check on the bird. It sort of looked like a finch, or maybe even a female cowbird (except it was too small to be a cowbird). Let’s just say the head looked like a female cowbird’s, but the body was more finch like in size.

It can hop. I put a bit of seed out on the ground and left it alone. It would just stress the bird for me to try and capture it. Maybe it will recover.

Please don’t say, it’s just nature, because cats are not native here. Also, my neighbor’s cat dug up all of my garden pea starts last year and pooped in the garden bed. Pea starts are expensive. People need to keep their cats indoors, or in a catio, or just supervise them outside so they don’t cause problems or be killed by dogs that should not be owned by humans as pets.

After I checked on the bird, I did go and look at my moth bucket. There were 7 specimens. Not many, but I went through them and here’s what I found. Six moths and one wasp.

*Cerastis enigmatica*, the Enigmatic Dart Moth

*Orthosia hibisci*, the Speckled Green Fruitworm Moth

*Egira crucialis* , I believe. Egira for certain though

Orthosia sp. I am undecided about species for this one.

The next moth below looks like it has a little pixie cap on. It’s one of my favorites. The red colors are so pretty. It’s in genus Orthosia like some of the others above, but I believe this one is Orthosia transparens.

I saved the best one for last. I have only seen this moth on two other occasions, but it one so remarkable, you remember it well. This is an owlet moth called Behrensia conchiformis. I would love to discover what makes the interesting metallic colors in the wings. The larvae of this species are foodplant specialists. They feed only on honeysuckle (Lonicera spp.) and snowberry (Symphoricarpos spp.) in the Caprifoliaceae.

Thanks for reading…especially for reading my rambling rants of the day. While I’d like to stick to just bugs, I am finding it somewhat therapeutic to include my feelings here, and to interject some of my opinions. They are mine and yours may be different. I respect that, but I hope perhaps upon reflection, even someone who might initially disagree with my perspective, might have a change of heart.

Uncategorized

April 5, 2025 – Herman finds a fly

Posted on April 5, 2025 by "BUGGING" YOU FROM San Juan Island Leave a comment

That’s right! Herman the Persian found something interesting in the yard when we were outside sunning ourselves a bit this afternoon. He found one of the Bibionid March flies (a female). If you read my post yesterday https://buggingyoufromsanjuanisland.com/2025/04/04/nuptial-gifts/, you might note that Bibionid flies were being hunted by Empis flies who rolled them into little balls as nuptial gifts used to woo the lady Empids to mate.

Female Bibionid fly digging chamber to lay her eggs.

Evidently, a few of these Bibionid flies escaped that destiny and actually mated with their own kind. THIS one, that Herman found, was hard at work digging her own death chamber where she would expire soon after laying her eggs. Incidentally, the adults are very short-lived, and in fact, live only about 5-7 days with the primary objective of mating, and for the adult female to lay her fertilized eggs. In spite of their brief existence, adults are also thought to be important early pollinators of orchard trees. Yes, you heard me right! Flies don’t get nearly as much credit for pollinating as they deserve to receive.

I watched her digging with her fossorial forelegs. It seemed to be an impossible task, but she made slow and steady progress. She was still hard at work before we went back into the house about half an hour later. I marked the spot with a rock so I could go back and check, but I suspect even with the rock nearby as a marker, it will be next to impossible to detect any disturbance in the soil tomorrow. We’re supposed to get rain this evening.

In approximately 30-35 days, the eggs she lays will hatch underground. The larvae will live in the top layer of soil and feed gregariously on leaf and needle litter, decaying organic matter, and sometimes on below-ground parts of plants.

If you’re curious, you can read more about Bibionid flies in the attached links. I did see some additional Empis fly males dancing about today with their Bibionid “balloons” or nuptial gift balls for prospective mates.

Thanks for reading. 🙂

References

Bugguide.net. 2025. Family Bibionidae – March flies. https://bugguide.net/node/view/3834

Morris, H. No date. The larval and pupal stages of the Bibionidae. Entomological Department, Institute of Plant Pathology, Rothamsted Experimental Station, Harpenden. https://core.ac.uk/download/pdf/212009582.pdf

Nuptial Gifts

Posted on April 4, 2025 by "BUGGING" YOU FROM San Juan Island 3 comments

Empis Dance Fly with Bibionidae fly as nuptial offering for a female Empis fly

This afternoon I would rate a 10/10 for entomological adventure. It happened outside, just behind our barn about 3:30pm. I went out to feed our resident raven and took a stroll over to a sunny corner of our property. As I neared an old barbed wire fence line, I noticed an aggregation of flies bobbing around over one of the native Ocean Spray (Holodiscus discolor) shrubs. Moving closer, as stealthily as possible, I saw these were Empis dance flies and I got very excited. There seemed to be about 15-20 in the group.

Empis Dance Fly (male) with Bibionid fly nuptial gift

I watched as I stood in the sun. The sun’s warmth felt really good on my body. Hopefully, we will have more sunshine and some days of vitamin D will infuse my cells and pull me out of this funk I have been wallowing in. The flies dancing in the sun were a sight. I crept forward a bit closer, trying not to slip into the fencing, but enough so as to get some video to share.

You will have to forgive me for the shake in the footage. It is not easy to remain steady and focus on a nervous fly that leaves its perch if you so much as breathe too deeply when you are moving the camera close enough to zoom in for a good macro shot. I think I was holding my breath a lot while I was trying to take pictures.

Empis Dance Fly with nuptial offering

This fly should be classified in the genus Empis. Last year, I found Empis barbatoides in our orchard. You can read an earlier blog post I wrote about them here https://buggingyoufromsanjuanisland.com/category/dance-fly/empis-barbatoides/ I believe these may be the same species, but I say this with a caveat. I am hoping to get my hands on a copy of the revisions by Sinclair, Brooks, and Cumming I have referenced below. It appears I may need this and the updated keys to try and ID my fly beyond genus level, so I’ve emailed the lead author and hopefully will hear something back.

If you look closely, you’ll see in some of the photos the fly is holding a balled up insect. This is a species of March fly in the family Bibionidae. I saw a few hiding around in the tall grass like this one in the photo below.

March fly (Bibionidae) hiding in the grass

Evidently, they were being picked out by the male flies and rolled up into a nice nuptial gift to present to a female Empis fly to entice her to mate. The male Empis fly will carry this balled up dead insect and “dance” around to attract a female. That’s what I found so fascinating to actually watch in person. It isn’t every day you see something like this! Since flies seem to be attracted to certain spots for mating aggregations (it’s called hilltopping), perhaps this is a spot where I might be lucky enough to see this action again.

References and Further Reading:

Alcock , John. 1973. The mating behaviour of Empis barbatoides Melander and Empis poplitea Loew (Diptera: Empididae), Journal of Natural History, 7:4, 411-420, DOI: 10.1080/00222937300770301

Bugguide. 2023. Family Empididae – Dance Flies. https://bugguide.net/node/view/6578

Pehling, D. 2004. Empis Dance Flies Empis spp. Bug of the Month . Scarabogram. https://crawford.tardigrade.net/bugs/BugofMonth40.html

Sinclair BJ, Brooks SE, Cumming JM. Revision of the western Nearctic species of Empis subgenus Enoplempis (Diptera: Empididae). Zootaxa. 2025 Mar 31;5615(1):1-200. doi: 10.11646/zootaxa.5615.1.1. PMID: 40173481. https://pubmed.ncbi.nlm.nih.gov/40173481/