Tag Archives: caterpillar

Caterpillar Rescue – Dagger in Distress!

Saturday, September 19, 2020. San Juan Island, WA – Caterpillar rescue!

Acronita impleta – Yellow-haired Dagger Moth caterpillar. San Juan Island, WA 09.19.2020


I found one of these several years ago (September 20, 2017 to be exact), so I recognized it immediately when I saw it squirming in the spider webbing along the house this morning. My husband said I should just leave it alone. “Nature is ugly sometimes and you can’t interfere.” Well, when it was still there four hours later, suspended mid air, and still squirming, my tendency to SAVE things kicked in. The spider living above that web was actually dead. I’m not feeling very guilty about stealing food from a dead spider.

Acronita impleta – Yellow-haired Dagger Moth caterpillar. San Juan Island, WA 09.19.2020
Acronita impleta – Yellow-haired Dagger Moth caterpillar. San Juan Island, WA 09.19.2020


I got a cup and gently pulled at the web and began the process of freeing this caterpillar. It took finding my reading glasses and getting some fine-pointed tools to gently ply away the sticky bonds and clean the strands off the caterpillar hairs.

Acronita impleta – Yellow-haired Dagger Moth caterpillar. San Juan Island, WA 09.19.2020
Yellow-haired Dagger Moth (Acronita impleta)


I think it looks pretty good! I even picked it some dinner and we’ll see if I can keep it healthy through pupation and adulthood.

Yellow-haired Dagger Moth (Acronita impleta)

More about Yellow-haired Dagger Moths here:

Thatch Ants Attack Caterpillar

I had my bearded dragon outdoors the other afternoon to get his 20 minutes of sunshine (me too!) when I spied something unusual moving in the grass. The object of my attention was a fairly large caterpillar lying in the middle of 25-30 voracious Thatching Ants (Formica obscuripes), intent on relocating the caterpillar (their dinner), even if they had to do it one bite at a time.

Observing them at work, I thought of how the Egyptian pyramids were built. Humans. Lots of them. Carrying those giant blocks and stacking them required formidable effort. Perhaps these ants in their orchestrated labor efforts would successfully lug this lepidopteran larvae back to their nest.

I did not stay and watch to the end. I watched just long enough and filmed this clip. I felt a bit sad for the caterpillar, wondered about the butterfly or moth it might have become, and I marveled a little about these industrious ants that cooperate for the collective benefit of the colony.

Ants are pretty amazing. 🐜🐜🐜

Stay tuned for more on Thatch Ants!

Silver-Spotted Tiger Moth (Lophocampa argentata)

I found this specimen at the Friday Harbor Post Office yesterday and picked it up to save in my collection. It’s a bit bird-pecked, but worth keeping for passing around at my upcoming insect talk at the library in October.

Lophocampa argentata Silver-spotted Tiger Moth
San Juan Island, WA
photo by Cynthia Brast-Bormann
August 27, 2019

Lots of folks emailed me earlier in the year with photos of caterpillars they were finding. The larval form of this moth looks like the two photos below, depending on the developmental instar.

Silver-Spotted Tiger Moth Larva Lophocampa argentata
Orcas Island, WA 98250
May 9, 2019
photographed by K. Rose
Silver spotted tiger moth larva Lophocampa argentata
San Juan Island, WA
April 26, 2019
photographed by L. Narum

These moths are fairly common throughout the San Juan Islands. The larvae feed on Douglas Fir (Pseudotsuga menziesi) and other conifers. The name, argentum comes from Latin referring to the silver spots on the wings of adults.

While larvae are defoliators, they are not usually present in high enough numbers to cause economic damage or require any chemical control. Also, while very pretty to look at, the caterpillars do have urticating hairs which can cause stinging, burning, or rash in sensitive people. Take a photo or observe them, but resist the temptation to pick them up!

Lophocampa argentata
San Juan Island, WA
August 27, 2019
photo by Cynthia Brast-Bormann
Lophocampa argentata
San Juan Island, WA
August 27, 2019
photo by Cynthia Brast-Bormann

White-lined Sphinx caterpillar (Hyles lineata)

I’m always excited when someone asks me to ID a bug for them! This came from the women over at Browne’s Garden Center – https://www.browneshomecenter.com/garden-center/, San Juan Island, WA. It’s the “black form” of the White-Lined Sphinx Moth (Hyles lineata). The larva are sometimes called Purslane caterpillars. They will eat Fireweed (Epilobium angustifolium), other fireweeds, and other various plants in the evening primrose family.

White-lined Sphinx Moth (Hyles lineata) caterpillar (black form)

Read more here:

http://www.silkmoths.bizland.com/Sphinx/hlinelin.htm https://bugguide.net/node/view/3071

Lophocampa roseata (Rosy aemilia)

I spent a good part of the day combing through my insect photos from the past 9 years. There are thousands. Finally, I found the ones I was searching for. I credit Victoria Compton on San Juan Island, WA  for helping me out on this one. She sent a photo the other day to my email with a caterpillar and had suggested an ID. Not only was she correct, but in ID’ing the caterpillar, it enabled me to match up one of my adult moth photos that had been sitting around nameless since 2016. The photos I found today were of the same caterpillar that had been a mystery to me since 2013. It’s a nice “aha” moment when you connect the dots! Below are the pics for you to see.

Lophocampa.roseata.July10,2016IMG_3310

Lophocampa roseata Photographed July 10, 2016 San Juan Island, WA


Photo0092

Lophocampa roseata larva Photographed October 6, 2013 San Juan Island, WA

This is a Tiger moth in the family Erebidae, subfamily Arctiinae. The scientific name is Lophocampa roseata (also known as the Rosy aemilia). It was first described by Francis Walker in 1868.  They are found in Western Oregon and Washington as well as in Southwestern B.C. and are associated with habitats of conifer forests and maple trees. The sources I checked list them as somewhat rare and Natureserve lists them as “critically imperiled.” So, I guess we have another beautiful Lepidoptera on San Juan Island to care for along with the Marble Butterfly!

***Critically imperiled Tiger Moth. Please post/email photos if you live in San Juan County, WA and come across one in the adult or larval stage.  Thanks! 

Photo0091

Lophocampa roseata larva Photographed October 6, 2013 by Cynthia Brast San Juan Island, WA


20180926_133138

Lophocampa roseata larva Photographed September 26, 2018by Victoria Compton San Juan Island, WA 

Helpful links:

http://explorer.natureserve.org/servlet/NatureServe?searchName=Lophocampa+roseata

https://www.inaturalist.org/taxa/224121-Lophocampa-roseata

https://www.butterfliesandmoths.org/species/Lophocampa-roseata

https://bugguide.net/node/view/247272

Lophocampa roseata larva
October 27, 2019
Three Corner Lake Road
Lophocampa roseata pupal case
Pupated 10-29-19

Lophocampa roseata larva
Found wandering in search of pupation site – October 27, 2019
San Juan Island, WA