This is one of my favorite garden residents (Eudioctria sackeni), or the Sacken Longhorn Robber. I remember the first time I saw one of these, I thought, “Wow, it’s an Ombre Fly!” If you didn’t know, “ombre” means the blending of one particular color hue to another, often from light tints to dark. The coloration in this particular fly is distinctly “ombre,” though it varies in individuals within the species.
Eudioctria flies are in the family group, Asilidae or Robber flies. They are voracious predators of small insects that can be pests of gardens and orchards. Here, you see this one enjoying a small dipteran (fly) of some variety, perched on the leaf of one of my mint plants. The mint is a popular scouting platform. On any given day in the summer, I’ll see 4 or 5 of these flies in a six foot strip of mint which has become quite abundant in the yard over the past few years. The mint seems to be quite attractive to pollinators, and it also provides shelter for other bugs and critters. Our little tree frogs love to sit in the mint too.
I’m going to start a new bug series called “What’s Biting Me?”
I’m starting this series because I have such bad reactions to bug bites in general, and I’m exasperated when people blame mosquitoes and spiders for everything. Also, if you’re one of those who is tired of it getting crowded here in the San Juans, feel free to share this with anyone who is thinking about moving here – or with anyone you WISH would move off the island. Maybe they’ll decide to live somewhere else. 😉
Epidode ONE, the San Juan Sniper
This is one of the Rocky Mountain Bite Flies (Symphoromyia sp.). It’s a Snipe fly in the family Family Rhagionidae, and it bit my husband today. Those are NOT my hairy legs. They’re my husband’s.
Rocky Mountain Bite Flies (Symphoromyia sp)
After getting some pictures, I went inside to look up what information I could find about the Genus and narrow down what species are in WA state. In doing so, I came across this interesting, and disturbing medical case report of a woman who had a severe allergic reaction to the bites of these flies. Now this was in the 70’s, in Forks, WA, but if this fly had bitten ME instead of my husband, it’s very likely I’d be the next case write up.
Attaching the paper in the link here if you care to read it. The woman could have D-I-E-D from anaphylactic shock.
You’ve been warned.
No worries, just stay indoors and you’ll avoid being bitten by the San Juan Sniper.
Symphoromyia Genus
Size: 4.7-9mm
Food: Females of some species of this genus are blood feeders. Symphoromyia females are common biting pests in the west. Males do not take blood meals. Both adults and larvae will prey on small insects.
Habitat: Adults are commonly found in woods near moist places, often found on foliage or grass, positioned with head resting head downward. Larvae occur in moist meadow soil, moss, decaying wood (incl. galleries of wood-boring insects), under bark, occasionally in water (bug guide.net).
References and Further Reading
Aldrich, J. M. 1905. A Catalogue of North American Diptera. Smithsonian Miscellaneous Collections 46:680.
Turner WJ. A case of severe human allergic reaction to bites of Symphoromyia (Diptera: Rhagionidae). J Med Entomol. 1979 Feb 8;15(2):138-9. doi: 10.1093/jmedent/15.2.138. PMID: 448692 https://www.tesble.com/10.1093/jmedent/15.2.138
I had my moth light up last night and found a handful of specimens still hanging out this morning at 06:30 when I got up, grabbed my coffee and went to check the station since the birds tend to start counting my specimens if I don’t beat them to the job. The problem with the birds counting is they EAT as they count. It’s even more irritating when the Yellowjackets are competing for tally rights.
Here’s a moth that was new to me. This is the Apical Prominent moth (Clostera apicalis). It is in the family Notodontidae (Prominent Moths),Subfamily Pygaerinae.
Clostera apicalis uses birch, poplar, and willow as host plants for larval development and sometimes the larvae form communal nests woven of silk threads.
The geographic range of this species is recorded from the northeastern and western U.S., across Canada, and north into the Northwest Territories. In the North, the species is univoltine ( one generation per year), and in the south, bivoltine (two generations per year). You will find adults flying from the months of May to August and larvae developing in August and September.
Lots of folks are asking, “Where are the pollinators?” I’m getting comments and questions about the absence of bees. Should we be concerned? Probably.
It’s been a weird spring/summer with lots of temperature fluctuations. That impacts when things bloom and what food is available. Bumble bees can fly when the temperatures are lower and I did see and hear them when our Golden Chain tree was in full bloom about two weeks ago. They may be on other blooming florals right now – like blackberries. If you have Catmint (Nepeta), Lavender, and Tomatoes or Nasturtiums about, the bumble bees should find these in another week or so. Usually I see them on Foxglove (Digitalis) and also in our Rhododendrons, but Foxglove is biennial and we don’t have any blooming this year, and I believe the Rhododendrons are already done blooming for the season.
In general though, I am noticing an overall decline in abundance of many insect species. We have two above ground, freshwater pools for water catchment and in years past, there have been lots and lots of insects needing rescue because they fell in and couldn’t get out. I was skimming bugs twice a day and this year, I might have found 4 or 5 needing rescue. That’s 4 or 5 total – when I used to find 20-30 floating in the morning.
That said, there are a few species where populations seem quite abundant. I’ve found lots of the tiny and very cute Broom Seed Beetles (Genus Bruchidius) everywhere in the yard. If you see these little black peppercorn-sized beetles, they are friends (a biocontrol for scotch broom).
Broom seed beetles on Nasturtium
So, is the overall decline in invertebrate populations because of climate change or something else? I think the decline of invertebrate species is due to a multitude of factors: habitat loss due to land use changes, weather fluctuations/climate change, introduction of pathogens as species move into previously unoccupied territory (due to climate shifts), but especially from pollution and contamination by all the products we use. These are additive and include anything and everything that leaves trace residues behind. It’s multifactorial and complex. Humans and our practices are altering ecosystems.
How to help? I don’t have any great answers. Can the few who actually care initiate changes and change the minds of the masses of people who don’t care and don’t want to change? Our education system isn’t helping. We continue to promote attitudes (even as adults who should know better) that evoke fear responses around insects, spiders, (and don’t even get me started on snakes) in our children. Instead of teaching children about ecology, biology, and life sciences, we shriek when we see a spider or a roach or mosquito and grab the can of raid. We want to garden and seek out gardening advice, but historically, even the extension communities have been pretty un-environmental in their approach to insects. For that matter, most of our Land Grant Universities’ agricultural and entomology departments have been funded by the large agrochemical industry. They have promoted use of pesticides over cultural practices. The agrochemical industry makes tons of pesticides that are applied all over the world every year. It’s a huge part of our economy. MONEY trumps nature.
My advice? Be curious about what you are using. Learn about ecology and food webs. OBSERVE nature. Investigate where your food comes from. When you buy garden or landscape plants, ask the company about what practices they are using to grow these plants. Choose native plants for landscaping. Look around your home and read the labels on what products you are using – especially for any products going down the drain. If you have pets, look up the ingredients on the products you use for treating fleas and ticks. Flea and tick treatments have neonicotinoids that are excreted in urine and poo. Ask your vet about alternatives. We all need to think about the implications of this. Neonicotinoids are killing our pollinators and other invertebrates.
References and further reading
Bonmatin JM, Giorio C, Girolami V, Goulson D, Kreutzweiser DP, Krupke C, Liess M, Long E, Marzaro M, Mitchell EA, Noome DA, Simon-Delso N, Tapparo A. 2015. Environmental fate and exposure; neonicotinoids and fipronil. Environ Sci Pollut Res Int. Jan;22(1):35-67. doi: 10.1007/s11356-014-3332-7. Epub 2014 Aug 7. PMID: 25096486; PMCID: PMC4284396. https://pubmed.ncbi.nlm.nih.gov/25096486/
Webb DT, Zhi H, Kolpin DW, Klaper RD, Iwanowicz LR, LeFevre GH. 2021. Emerging investigator series: municipal wastewater as a year-round point source of neonicotinoid insecticides that persist in an effluent-dominated stream. Environ Sci Process Impacts. May 26;23(5):678-688. doi: 10.1039/d1em00065a. PMID: 33889902; PMCID: PMC8159912. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8159912/
This is one of my “Know your pest predators” posts, featuring one of our PNW flies. Flies are all too often maligned and under-appreciated. We think of flies as spreading disease and being a nuisance, yet many of them perform incredibly important jobs as pollinators and pest predators. Yesterday I was sleuthing flies in the yard and found these metallic green beauties. Here is a Dolichopus (“doe-LICK-uh-pus”) male and female. The “dolicho-“ part means “long”, and the “-pus/-pod” part means “leg” or “foot.”
Some species of Dolichopus males (like this one) have little “flags ” or “mitten” front feet they wave or flap around to woo the ladies. Reading about this very large group of flies has been interesting and you can learn more about their courtship behaviors in Van DuZee et al. (1921).
Dolichopus sp. male fly
These flies are predators of small, soft-bodied invertebrates as adults and during their larval stage. You can thank them for helping keep populations of aphids under control in your garden.
Dolichopus sp. fly (male)
You’ll find these flies in northern latitudes in North America. “Dolichopus species are among the largest and most common members of the family Dolichopodidae in North America. The majority of Dolichopus species prefer humid habitats and some are restricted to saltmarshes,” (Pollet et al. 2004).
MARC A.A. POLLET, SCOTT E. BROOKS, JEFFREY M. CUMMING. 2004. “CATALOG OF THE DOLICHOPODIDAE (DIPTERA) OF AMERICA NORTH OF MEXICO,” Bulletin of the American Museum of Natural History, 283, 1-114,
Van Duzee, M. C., Cole, Fr R., and Aldrich, John Merton. 1921. “The dipterous genus Dolichopus Latreille in North America.” Bulletin of the United States National Museum. i–vi, 1-304, 16 pls. https://doi.org/10.5479/si.03629236.116.i
Something happened in the yard yesterday afternoon. We have a fruitless cherry tree in a cage that I didn’t plant. At least I think it’s a fruitless cherry tree. It sort of popped up on its own.
In the beginning, I didn’t really want it there, so I cut it down – a few times. It kept coming back, intent on sticking around. A couple of years ago, I just stopped trying to get rid of it. I even put a little cage around it. That was actually for the juncos that built a nest in the grass below that little tree though, to keep them safe from the mower.
Aside from me personally whacking it down a few times, the little tree has suffered other adversities. It has been attacked by cherry slugs (sawfly larvae). They ate its leaves.
Sawfly larva or Cherry Slug
It has had a few tent caterpillars munching too. One year that it was super dry, it lost its leaves and I thought it was dead. Only it came back again. I started to pay more attention to this little tree, even watering it in the summer. It’s not very tall, but this year it looks more healthy than ever before.
Last year, I noticed in the spring that it put out these cool little red bumps on the stem just above the leaf.
extrafloral nectariesFormica ascerva ant at extrafloral nectaries
Those little bumps soon had little red and black ants visiting. I learned the red bumps are extrafloral nectaries. They produce nectar that attracts pollinators to the tree. I haven’t seen any flowers, so I’m not sure what would be pollinated. Maybe the tree isn’t old enough yet. I’m still learning. I sure need to figure out if I’m right that it’s a fruitless cherry.
Well, the other thing that is interesting is shortly after the little red bumps attract the red and black ants, there are little black aphids. I’ve seen this for 2 years in a row now. The ants tend those little aphid flocks like sheep. They are guarding them in exchange for the sugary honey dew the aphids produce.
The aphids and the ants seem to multiply. I have seen 2 or 3 ants per leaf with aphids. Not all the leaves have aphids, but maybe 1/3 of the tree does, and each guarded by the ants. The ants are Formica ascerva species.
They are interesting in their own right because aside from guarding the “sheep,” they also are fierce warriors, driving away (and killing) the large Camponotus sp. carpenter ants that try to invade every spring.
This colony of Formica ants lives under a bedroom of our home. They are welcome to stay since they don’t eat wood.
Today, when I looked out the window though, I saw something challenging the fearsome Formica ants. There were birds inside the tree caging and they were hungrily pecking and even tearing at the leaves with aphids. I grabbed and clumsily set up my camera to video the scene.
Birds attacking aphids farmed by Formica ascerva ants
I saw finches first, then there was a chickadee, and even a hummingbird. I thought I saw bumble bees, but they wouldn’t have been eating the aphids. Perhaps they were visiting the extrafloral nectaries or maybe even sipping honeydew produced by the aphids, but I wasn’t close enough to be certain.
Afterwards, I went out to survey the damage. I saw one leaf with lots of shreds. Aphid parts scattered about. Ants wandering somewhat aimlessly. Another leaf had an ant that died courageously in battle protecting his little flock.
I wanted to share my observations with you because a lot of folks really dislike aphids. Others also dislike ants and don’t understand their role in nature’s ecosystems. Maybe this will help others to understand there are a lot of hungry birds that eat aphids (and ants). Without them, the birds might not find enough food to feed their nestlings. It’s all part of the cycle of life.
If you see aphids your garden that you are worried about, you can mitigate some of their feeding damage by hanging a hummingbird feeder nearby. The hummingbirds have to have protein along with all that carbohydrate sugar water and they will most certainly find your aphids delicious. In fact, insects and spiders make up about 85 % of the diet of hummingbirds. Birds need bugs. And not all ants are pests. Some are extremely beneficial. I challenge you to take up bird and bug watching. You will not be disappointed!
Thanks for reading!
Below are more images of the birds feeding on the aphids inside the caged tree.
References and further reading
Bentley, B. L. (1977). Extrafloral Nectaries and Protection by Pugnacious Bodyguards. Annual Review of Ecology and Systematics, 8, 407–427. http://www.jstor.org/stable/2096735
I found this interesting beetle on the side of our pool the other afternoon and realized I’d actually seen one like it about a week earlier, so I did some digging to figure out what it was. This is a Spider Beetle (subfamily Ptininae), and the species is Ptinus sexpunctatus or Six Spotted Spider Beetle.
These beetles are quite small at about 2.8-4.2 mm. I used my clip-on Apexel macro lens to get these photos. What I found about this beetle’s life history is that the species is not native to North America. The very first record I found was in Pennsylvania in 1915 where the beetle entered via an imported English Walnut, but subsequent discoveries of populations are as recent as 2003 in Nova Scotia, and 2004 in Utah (Majka et al. 2007). I have not found any data as to how recently they may have arrived in the PNW, and found only 1 other record in WA state, aside from my own, when I searched on iNaturalist
Records of Ptinus sexpunctatus – iNaturalist (as of 05.25.2024)
Within its native range, Ptinus sexpunctatus, is a known associate of cavity- nesting solitary bees. These include bees in the genera Osmia and Megachile. It has also been collected in the galleries of longhorned beetles (Cerambycidae) in oak (Quercus) forests (Majka et al. 2007). Because of these associations, it is possible that Ptinus sexpunctatus was accidentally imported when two Osmia bee species, Osmia cornuta (Latreille) from Spain and O. cornifrons (Radosz- kowski) from Japan, were introduced into the United States for research and evaluation as pollinators of tree fruits (Cane 2003; Majka et al. 2007). Majka et al. (2007) believe that after arriving in the U.S., Ptinus sexpunctatus colonized the nests of our native Osmia bee, (Osmia lignaria).
The relationship and impact of the nest association between Ptinus sexpunctatus and Osmia lignaria needs further study. Some observations of these associations in Europe describe the beetle as being destructive to Osmia nests, preying on bee larvae and pupae (Majka et al 2007).
Cane, J. H. 2003. Exotic nonsocial bees (Hymenoptera: Apiformes) in North America: Ecological implications. pp. 113–126. In, K. Strickler and J. H. Cane (Editors). For Nonnative crops, Whence Pollinators of the Future? Thomas Say Publications in Entomology: Proceedings. Entomological Society of America. Lanham, Maryland, U.S.A. 204 pp.
Majka C.G., Philips T.K., Sheffield C. (2007) Ptinus sexpunctatus Panzer (Coleoptera: Anobiidae, Ptininae) newly recorded in North America. Entomological News 118: 73-76 (Full text)
It’s a short clip, and you’ll have to check out the end to see this little beetle take flight. I fished this one out of the pool and it’s the 2nd one I’ve seen this week, albeit a new one for me to observe. I believe this is Hylastes macer, but hoping a friend will take a look for me to confirm. I have tentatively based my ID on size (approx 5mm) and locale being under our Shore Pine trees, but I wasn’t confident using Wood’s key with only my photo and video in lieu of an actual specimen under the microscope. At minimum, Hylastes should be correct for Genus. These beetles are in the family Curculionidae and subfamily Scolytinae, one of the Bark and Ambrosia beetle species.
As to their life history, they construct galleries in phloem tissues of roots and stumps of Pinus or Pine trees and occasionally Picea or Spruce trees. According to Atkinson (2024), there are six species of Hylastes known in Washington State. Some of the species in this genus range from BC to CA. For more on distribution, take a look at Wood, 1982.
While identifying a bug is part of the process, the most fun for me is observing their behaviors. I knew when I saw the march of those little front feet, that the launch was about to take place.
Evans, A. 2021. Beetles of Western North America. Princeton University Press.
Wood, S.L. 1982. The bark and ambrosia beetles of North and Central America (Coleoptera: Scolytidae), a taxonomic monograph. Great Basin Nat. Mem. 6: 1-1356.
I’m doing a short write up of this fly just to get you thinking a bit. It was observed April 29, 2024 on San Juan Island, WA. While identification to Genus/Species may not be possible until I can actually catch a specimen to be keyed out, it is Family Tachinidae and Tribe Goniini. Hoping to come back with at least a Genus update at some point.
What I want to SHARE is the life history of this tribe of flies. The Goniini flies are parasites of various Lepidoptera, mostly Noctuids, Arctiids, and Lymantriids. Translating this for you a bit, it would be cutworms (if you’re a gardener) , tiger moths, and tussock moths.
How does this play out?
The female Goniini fly lays a “black microtype,” usually ovate and flattened egg, varying in size from very small to medium, on foliage utilized by the feeding host caterpillar. The caterpillar (usually Noctuids) munch the foliage, ingesting the fly egg. The caterpillar will continue feeding and then wander off to complete its life cycle as a pupa. At some point after ingestion by the caterpillar, the fly egg hatches and the fly larva develops inside the body of the pupating moth that is inside its chrysalis.
A myriad of ecological relationships exist in nature that are often unobserved. Many remain undescribed or unknown. Sometimes, they are disrupted by humans who intervene out of ignorance. If you’re one of those folks who squish what you believe are cutworm pupae in your garden bed, you might be smooshing the pest predator developing inside.
Hmmm, I was trying to think of a catchy title. “Louse in the House” made you look, right? Well, indeed one did escape and I can’t find it. Would you like to come over for dinner tonight? I thought I saw it flying around the dining room.
Here’s how it happened. Yesterday afternoon, a bird hit the window. It was a hard strike on a window where we haven’t had many bird collisions. I suppose I’ll have to make more Acopian Bird Blinds to put up. They’ve sure help mitigate the bird strikes. Link to DIY instructions here: https://www.birdsavers.com/make-your-own/
Back to the bird. I went out to see if the poor bird was still alive. It was, but died in my hands soon after I picked it up and carried it into the house to assess for injuries. I took the bird into the bathroom so I could shut out my ever-curious indoor cats, Herman and Nimbus. After realizing I was holding a lifeless body, I set the bird down in the bathtub. Right away, I noticed a fly crawling through the bird’s feathers. Hurriedly, I left the bathroom, grabbed my camera, and went back to examine my specimen more closely.
Hippoboscid Fly (Icosta americana)
As I bent over to look through the feathers, a fly zoomed up and nearly entered my nostril. I backed away, rubbing my nose. Wouldn’t be my first strange experience with a fly. There was that incident with the botfly that could have been a medical ophthalmological emergency. Don’t ask. You truly don’t want to know.
Leaning back over the tub, I started to look through the feathers again, but thought better. I went out of the bathroom again. This time to retrieve a large plastic bag and a collection vial for specimens. The bird went into the clear plastic bag. Now, I could look while containing the flies in the bag if there were others to be found.
I found two more.
These are Louse Flies in the family Hippoboscidae. The ID for this particular species is Icosta americana. Also, my husband identified the bird as a juvenile Brown Headed Cowbird (Molothrus ater). Strangely, this species is known to be chiefly associated with the bird families Accipitridae (birds of prey – hawks), Phasianidae (pheasants), and Strigidae (owls). So, why might it be on a cowbird? The bizarre exception. Maybe the cowbird parents laid their egg in the nest of one of the above? I suppose it will be a mystery.
Hippoboscid louse flies are pretty interesting. First off, don’t they look weird? Trust me when I tell you they are one of the most bizarre families of flies out there. They are obligate ectoparasites that feed on the blood of their host, nothing else. Unlike other fly groups, both male and female flies in this family feed exclusively on blood.
There are more than 200 species of Hippoboscid flies, and each species is particular about what sort of host it feeds on. Some feed on sheep, some on deer, others on bats, but the ones I found feed on birds. In fact, approximately 75% of species of Hippoboscid flies are bird parasites. Of these 75%, some are so picky, they only prefer a particular species of bird.
Another interesting thing about these flies is the fact they vector diseases like Avian Malaria, West Nile virus, and various Trypanosomes among the host species they parasitize. Unlike some other Hippoboscid species which have deciduous wings (wings that are quickly lost when reaching a host), the ones that parasitize birds can fly during their entire adult life. This means if their host dies, like my bird that hit the window, the flies are able to leave the bird’s body and fly off to parasitize another bird host.
While one fly may have attempted to target my nose, these flies are not known to parasitize humans, although incidental bites have been recorded. Some species of female Hippoboscid flies are actually known to only be able to develop their eggs from the blood of their particular host species.
While on a host, Hippoboscid flies move about with ease. They have bodies that are dorso-ventrally flattened, somewhat like an unfed tick body or a squished bug body. In fact, the Hippoboscid flies that parasitize deer are often mistaken for ticks. Because of the flattened body, sometimes these flies are referred to as flat flies. This shape makes it easy for them to glide between fur or feathers, and it also makes it hard for the host to groom them off.
The most remarkable thing about Hippoboscid flies is their reproductive biology. It is known by the term, Adenotrophic viviparity. Adenotrophic viviparity is where eggs hatch inside the female, and the larvae are fed internally until they are mature enough to pupate. In layman lingo, the female fly gives birth to a single live larva just as it is ready to pupate. She has invested all her resources into producing a single offspring.
This is unique as most fly species cast eggs onto a substrate and the eggs hatch into larvae, feed independently of the parent, pupate, and emerge as adults. With Hippoboscid flies, the female parent retains the single egg inside her uterus, the egg hatches into a larva, and she feeds it with special milk glands until the larva reaches the last stage of larval development or “prepuparium.” Finally, the adult fly “births” her offspring larva enclosed in a shell that quickly hardens into a true pupa. With Hippoboscid species that parasitize birds, the adult fly will leave her pupa in a bird’s nest or roosting site where it can easily find a host when emerges as an adult. For more on the life cycle of Hippoboscidae, you can view one of my YouTube videos here – https://youtu.be/zCD1B2GjCxU
*** In case you’re sitting here scratching your head and I wasn’t clear in the text, ALL of the collective names for Hippoboscid Flies include the following: Flat Fly, Louse Fly, Ked Fly, or just plain ole Ked. And yes, they ARE known to have a painful bite!
References and Further Reading
Coatney, G. R. (1931). On the Biology of the Pigeon Fly, Pseudolynchia maura Bigot (Diptera, Hippoboscidae). Parasitology, 23(04), 525.
Dick, C.W. 2006. Checklist of world Hippoboscidae (Diptera: Hippoboscoidea); Department of Zoology, Field Museum of Natural History: Chicago, IL, USA, pp. 1–7.
Levesque-Beaudin, V. Sinclair, B.J. 2021. Louse fly (Diptera, Hippoboscidae) associations with raptors in southern Canada, with new North American and European records. International Journal for Parasitology: Parasites and Wildlife, 16: 168-174. ISSN 2213-2244. https://doi.org/10.1016/j.ijppaw.2021.09.007
Maa, T. C. 1969. a Revised Checklist & Concise Host Index of Hippoboscidae (Diptera). Pacific Insects Monog., Honolulu: Bishop Museum, Honolulu, Hawaii. 20: 261–299. http://hbs.bishopmuseum.org/fiji/pdf/maa1969b.pdf
Santolíková,A.;Brzonˇová, J.;Cˇepicˇka,I.;Svobodová,M. 2022. Avian Louse Flies and Their Trypanosomes: New Vectors, New Lineages and Host–Parasite Associations. Microorganisms. 10, 584. https://doi.org/10.3390/ microorganisms10030584
Bugging You From San Juan Island 