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.
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.
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/
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).
Hypogastrura sp. springtails
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!
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
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 MothEgira crucialis , I believe. Egira for certain though Orthosia sp. I am undecided about species for this one. Ophion wasp.
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.
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.
Morris, H. No date. The larval and pupal stages of the Bibionidae. Entomological Department, Institute of Plant Pathology, Rothamsted ExperimentalStation, Harpenden. https://core.ac.uk/download/pdf/212009582.pdf
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
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/
I didn’t turn on my moth light last night. I thought about it, but supposed I just wasn’t feeling all that motivated. If I’m completely honest with myself, I am feeling a bit blue. Maybe more than a bit. I wrestle with feeling shut out of the “enviro” community on the island and have felt snubbed by some of the folks in certain organizations. Life on an island can be great, but there are times when it feels like you’re in a fishbowl. Some people don’t get beyond 8th grade social networks. Shrugging here. 🤷♀️ I am just going to continue to do my bug thing and if people want to connect, they are always welcome. Sometimes I get really great emails and feel like my efforts to share what I know about bugs matter. I hope so. We need bugs. Even the ones that aren’t perceived as charismatic as a butterfly or a bee.
Here’s a moth that made me think of a funny story to share. This one’s for my daughter. I hope she will get a laugh out of it. We used to have a rabbit named Izzy. Her full name was Izzy Belle Cottontail. She was supposed to be a wild rabbit. How did we come to have her? A neighbor’s dog killed her nest mates and she was the only one to survive. They brought her to me asking for help. She wasn’t but days or maybe even hours old. Her eyes were closed and her umbilical cord stump was still attached. I tried to give her to my rehabber friend, but she was overwhelmed. I ended up caring for Izzy. Bottle feeding every hour or so, even through the night. When she was old enough, we tried to release her. She ran back in the house and that was that. She came with us when we moved to Washington…all the way from Texas. If you want to see a video of Izzy, you can check out the YouTube link here: https://youtu.be/6S0qnwgzLbM?si=JsMYN8rG1Hfu67FB
Izzy Belle the Cottontail
So why does this moth in the video below remind me of Izzy? Well, Izzy had a really bad habit of chewing things. Rabbits have to wear their teeth down, but I think young rabbits just want to try everything out. One morning my daughter got up and came to get me. She said, “Mom, Izzy gave me sprigs.” She did indeed have “sprigs” of hair sticking up where Izzy had chewed off pieces in the night. Izzy gave me sprigs a few times too. In spite of her chewing and other unfortunate habits, we loved Izzy dearly and she lived a very long and happy life with us.
This little moth is Orthosia hibisci, the speckled green fruitworm moth. As you can see, it has little “sprigs” sticking up from the top of its head too. Those aren’t antennae, but they are cute! Orthosia hibisci is a moth in the Noctuid family. The caterpillars are sort of a generic green. They like chewing too, but fortunately, it’s limited to leaves. You might find them on willow, birch, maple, or other various deciduous trees (including fruit trees like plum and cherry). The adults are typically one of the earliest species to emerge in spring.
Orthosia hibisci, Speckled Green Fruitworm Moth, Observed April 1 2025 on San Juan Island, WA Orthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm MothOrthosia hibisci, Speckled Green Fruitworm Moth
Check out the links below to find out more about Orthosia hibisci
I hope it’s safe to say that Spring has finally arrived in the San Juans. We have enjoyed tiny blips of sunshine the past two afternoons, enough to awaken life in miniature around our home. I’ve found these tiny lives going about business on the “highway” around the top of our above ground pool, crumbled mounds of dirt in hard-packed soil where little mining bees have excavated their way to the surface from a long winter sleep, and a suite of species of flies (our best early spring pollinators) sipping at the miniature chickweed flowers that opened overnight. I’ve also seen my first tiny “sugar” ant in the house, most definitely a harbinger of spring!
In these days where we are likely weary of the many assaults on our souls – from reading that we are at the precipice of mass species extinction to the news reports of fires and other natural disasters (intensifying from climate change), and the horror of what we face watching our nation torn apart and not really knowing what the fateful consequences of unchecked power will be, I hope you will do as I am trying to do…take each day moment by moment, and find some beauty wherever you can. Remember the dandelion that blooms in the crack in the concrete. If you’re reading this, go outside and B-R-E-A-T-H-E.
Yesterday I saw the first Yellow Rumped Warbler of the season. The Violet Green Tree Swallows are going to show up any day now. Go soak yourself in nature while we still have nature around us.
Golden Dung Fly (Scathophaga stercoraria)Face Fly (Genus Musca) on Drago’s backCluster Fly (Pollenia sp)Cluster Fly (Pollenia sp)Seven Spotted Lady Bug (Coccinella septempunctata)Seven Spotted Lady Bug (Coccinella septempunctata)Blowfly (Calliphora sp)Face Fly (Genus Musca and I believe Musca autumnalis)Cluster Fly (Pollenia sp)Fungus Gnat (Family Mycetophilidae )Vinegar Fly (Genus Scaptomyza) Fungus Gnat (Family Mycetophilidae )Pea/Bean Weevil (Genus Bruchidius)Pea/Bean Weevil (Genus Bruchidius)Fungus Gnat (Mycetophilidae)Fungus gnat (Mycetophilidae)Fungus Gnat (Mycetophilidae)Darkling Beetle (Tenebrionidae)Dark Winged Fungus Gnat (Sciaridae family)Nut Leaf Weevil (Strophosoma melanogrammum)Slender Springtail (Orchesella cincta)Nut Leaf Weevil (Strophosoma melanogrammum)Harvestman (Phalangioidea)Narrow Barklouse (Genus Graphopsocus)This is either a Diapriidae Wasp (some use Mycetophilidae fungus gnats as hosts for development) or Braconidae (maybe Aphidiine) Mining Bee (Andrena sp)Mining Bee (Andrena sp.)Mining Bee (Andrena sp.)Mining Bee (Andrena sp.)Mining Bee (Andrena sp.)Mining Bee (Andrena sp.)Mining Bee excavationMining Bee excavationCarpet moth (Larentiinae) hoping to escape last night’s deluge
I’ll leave you to shadow dance with this happy little Cereal fly on my blue garden chair….💙
I went for a walk yesterday on Three Corner Lake Road just to get out of the house. Springtime on San Juan Island has been cold and dreary, but sometimes there’s a moment or two when the sun peeks out, giving a bit of hope that the winter doldrums are coming to an end. Don’t get me wrong, I love the Pacific Northwest, but the Visitor Center’s claim that San Juan gets 247 days of sunshine a year is a stretch. I think they actually count the days when it is overcast and rainy as long as the sun peeks out for just a minute before the clouds darken the day again.
It was cold and I wasn’t expecting to see any insect activity, so I was surprised to find this long time ant colony with a mass of individuals near the top of the nest. The sun had been out intermittently, so I believe what was happening was the workers were at the surface to warm themselves (thermoregulating). There were a few straggling workers carrying thatch debris (conifer needles) to the nest from the forest. If the weather had been nicer, I would have enjoyed plopping myself into a chair to ant watch for an hour or so. They are quite pretty when you see them up close.
Western Thatching Ants (Formica obscuripes) are native to our region. They seem to like forest edge habitat, and you’ll find the nests situated in areas where there is some clearing to take advantage of the sun’s warmth. These ants are considered general omnivore-predators. They scavenge or prey upon insects and other arthropods for food. Foraging activity takes place both on the ground and on vegetation, including high in trees. Thatch ants also harvest honeydew from aphids and other homopterans as well as from extrafloral nectaries. You can read more about extrafloral nectaries or EFN’s (little nectar producing glands on plants) here https://bygl.osu.edu/node/1774 or check out one of my earlier blog posts about them here https://buggingyoufromsanjuanisland.com/2022/05/17/what-are-extra-floral-nectaries%EF%BF%BC/
Extrafloral nectary on Fruitless Cherry Tree
The ant workers are considered weakly polymorphic, which means they have only slight variations in size and shape within the worker caste as opposed to other species where workers may be monomorphic (all the same size and shape), or strongly polymorphic (a high degree of variability between worker sizes and shapes). You can read more about polymorphism in ants here https://www.antwiki.org/wiki/images/1/1c/Wheeler_1908f.pdf .
Given all the information you’ll find from pest control companies online about these ants and others, you might ask, why or if there is any benefit to having these ants around. The answer is YES! Western Thatching ants are beneficial in ecosystems because they not only aerate the soil with their burrowing practices in nest construction, but they also provide FREE pest control, helping regulate populations of other insects that defoliate forests, fruit trees, and even our vegetable gardens. They also help clean up the environment through scavenging dead animals. There is no need to eradicate these nests and if you get into ant watching, they might provide a bit of intriguing summer entertainment. Pull up your lawn chairs and sit and watch with your friends. As long as you aren’t poking the nest, they are not inclined to bother you at all.
This was Wednesday’s bug of the day. I’m a day behind writing up my post. Although I have tried to get out for a quick bug search every day, it’s been overcast and/or drizzly here this past week. I was excited to see this little fly hunkered down on a twig of our fruitless cherry tree, the tree that I whacked off as an unwanted upstart for several years before I discovered how interesting it is.
Western Forest Sedgesitter, (Platycheirus trichopus), I believe
That tree is a mini ecosystem: floral nectaries that feed the aphids, aphids, slave making ants that have fights to the death (winning) with the carpenter ants that try to invade our home every spring, and the birds that rip the leaves apart trying to get the aphids. Now I can add Syrphid flies to the list!
That’s what this is. A syrphid fly. Syrphid flies eat aphids. It would make perfect sense for this adult to lay eggs on the tree, though I’m not sure what would happen because the ants that farm those aphids are certainly willing to die defending them. I could definitely see the ants overtaking the syrphid fly larvae. Nevertheless, the fly flew off. Somewhere.
This species, as mentioned earlier is pretty small at only about 6.8-9.4 mm. Geographic distribution ranges from the Rocky Mountains west from Alaska to Mexico (bugguide.net). Adults of this genus are known to feed on the pollen of wind pollinated plants like Willow (Salix sp.) and various grasses (Poaceae), and sedges (Cyperaceae). It is believed they are better adapted to activity in cooler temperatures and that fits with yesterday’s rather gloomy spring day.
Bugging You From San Juan Island 