Archive for the ‘Coyote Brush’ Category

Coyote Brush Blooming at the Bluffs

Tuesday, September 14th, 2010

I went back to the Bluffs last weekend, checking out the invertebrates in and around the coyote brush (Baccharis pilularis). There was a big fundraiser walk (the Avon Walk for Breast Cancer) going on at the time, so instead of checking the coyote brush up near the Lois Sidenberg overlook, I avoided the crowd by wandering into Mishopshno Meadow, north of the Artists’ Passage.

The first thing I noticed was this fly:

The helpful dipterid experts at Bugguide were quick to ID this as a sinuous bee fly (Hemipenthes sinuosa), a widespread North American species. The “sinuous” in the name refers to the wavy border between the black area at the front of the wing and the clear area at the back of the wing. The fact that there is a rounded black “meatball” along that border near the tip of each wing is what tells us this is H. sinuosa; other members of the genus have a more jagged border. According to Wikipedia, Hemipenthes larvae are hyperparasites on parasitic Hymenoptera (bees, wasps, and allies).

Not far from where I photographed the sinuous bee fly, I noticed a web with a cool-looking stabilimentum of trash running down the middle, and took this photo:

Silly me. I didn’t even notice what was sitting at the center of the web until I got home and looked at the images on my computer. Here’s a closer view:

That’s a female trashline orb weaver spider (Cyclosa turbinata). She spins a fresh web each night, using the debris from the old web (and the body parts of her prey) to build the stabilimentum, which she then uses as camouflage — highly effective camouflage, judging from my experience.

I photographed a second trashline orb weaver female, again without realizing it, a few minutes later:

Here’s the (slightly fuzzy) closeup. Again, she’s perched right at the center of the web, which I assume lets her respond quickly when she detects vibrations:

In both closeups you can see the two raised bumps on the dorsal side of the spider’s abdomen, near the front. Those bumps were cited by my helper on Bugguide as cementing the ID as C. turbinata.

I had fun examining the newly emerging flowers on the coyote brush. Coyote brush is dioecious, meaning that male and female flowers grow on separate plants. Here are the flowers just beginning to emerge on a male plant. The unopened buds have a globular shape, and the flowers, when they appear, form relatively shallow yellow disks:

Here are the flowers beginning to bloom on a female plant. The unopened buds are more elongated, and the flowers, when they appear, consist of long white filaments:

Later in the year, when the female plants go to seed, the coyote brush is filled with white, fluffy masses that blow away on the wind, each tuft of strands terminating in a single seed. The ability to disperse via wind is one of the things that makes coyote brush so effective at colonizing new areas, as it currently is doing in Mishopshno Meadow.

The female coyote brush flowers seemed to be much more effective at attracting honey bees (Apis mellifera) than did the male flowers, at least during my visit:

I also noticed this wasp crawling through the blossoms on a female plant, flicking its wings:

The Bugguide experts tell me this is a spider wasp in the family Pompilidae. According to Wikipedia’s spider wasp article:

Spider wasps are long-legged, solitary wasps that use a single spider as a host for feeding their larvae. They paralyze the spider with a venomous stinger. Once paralyzed, the spider is dragged to where a nest will be built – some wasps having already made a nest.

A single egg is laid on the abdomen of the spider, and the nest – or burrow – is closed.

I wonder if this wasp would have been interested in the nearby trashline orb weavers.

Finally, some shots of insect homes without actual insects:

Here’s a mass of old leaves and webbing that I’m guessing might have been holding an orange tortrix (Argyrotaenia franciscana) caterpillar or pupa, though I’m not sure. I’m curious what Charley Eiseman thinks about that.

I also liked this shot of a gall from the stem gall moth (Gnorimoschema baccharisella), with what I think is an emergence hole:

Here’s an old G. baccharisella stem gall, dried out with the passage of time, also with an apparent emergence hole:

Even though the background is fuzzy, you can recognize the location if you’re familiar with the Bluffs. The tip of the dead stem divides the north-south row of tamarisk (on the left) from the blue-gum eucalyptus of the Artists’ Passage (on the right). That first blue gum is actually the same tree I wrote about previously that blew over in the big wind back in January. It seems to be doing okay in its new, recumbent position.

What’s Eating the Coyote Brush at the Bluffs?

Thursday, September 9th, 2010

It had been a while since I took my favorite walk at the bluffs, from the Lois Sidenberg Overlook down through the coastal sage scrub, and so I was surprised a few weeks ago when I noticed a big change: the coyote brush (Baccharis pilularis) is heavily infested with some sort of insect. The foliage of nearly every plant is filled with silk webbing, many of the leaves partially or completely eaten, and what looks like caterpillar poop (frass) sprinkled throughout.

At first I couldn’t see what was making the webs, but after a while, looking closer, I started to notice a few of these guys:

If I got too close or jiggled the foliage they would scuttle backwards, hiding themselves in the mass of leaves and webbing they had constructed.

I tried posting some photos to Bugguide, but haven’t had any responses so far. But I think I know what they are: orange tortrix (Argyrotaenia franciscana), a moth that is a common agricultural pest in the western states, especially near the coast.

Most of the coyote brush near the top of the trail is so infested that it’s hard to find a single clump of leaves that isn’t full of webbing. Other plants, which apparently were infested earlier on, have nothing but bare twigs at the outer tips of every branch.

I’m curious to see what happens to the coyote brush. There are a number of parasitic insects that prey on orange tortrix; my guess is that the outbreak will eventually be controlled by them, and the coyote brush will come back, just as it came back from being heavily pruned by green leaf beetle larvae, Trirhabda flavolimbata, at the marsh last year.

I think the coyote brush can probably handle the orange tortrix and leaf beetles, just like it handles the stem gall moths (Gnorimoschema baccharisella), bud gall midges (Rhopalomyia californica), and all the other creatures that live on it. They’ve evolved together, adapting to each other’s presence, and over the long haul the coyote brush seems to be doing just fine.


Tuesday, June 2nd, 2009

I was walking at the Carpinteria Bluffs with William the other day, and noticed this on a coyote brush:


I think it’s an old, dried-out bud gall from the same midge I mentioned previously, Rhopalomyia californica. I like that you can see what I assume are the holes made by the adult midges when they emerged from the gall. I’m curious what the adult insect looks like. I’ve tried googling for images of it, but so far I haven’t found any. At least I have an idea of how big they are: just big enough to squeeze out of those holes.

Here’s an image I did find: Blogger user Raphael posted it in an item about wetland restoration at Shoreline Park in Long Beach:


This gall, which is still on a living plant, shows the same emergence holes as my dried version. I wonder what it looks like when the midges emerge. Do they all come out at the same time?

I’d really like to see that some day.

Update: They do emerge together. Check out this amazing series of photos taken by Charles Baughman on March 28, 2010, of a bunch of adult Rhopalomyia californica emerging in Boulder Creek in Santa Cruz County: Coyote Brush Bud Gall Midge – Rhopalomyia californica.

Later update: I take back part of what I wrote above: I don’t think those photos by Charles Baughman show adult midges emerging. I think they show the spent exuviae left behind after the emergence. Still beautiful and amazing images, of a phenomenon I’d still love to see firsthand. As I write this, at the tail end of 2010, we’re coming up on R. californica emergence season. I’ll make a point of checking those galls over the next several months, and see what I can find.

Green Leaf Beetles

Tuesday, April 28th, 2009

Those beetle larvae I previously noticed all over the coyote brush at the marsh are now turning into adult beetles. Specifically, Trirhabda flavolimbata, a type of skeletonizing leaf beetle. Here’s a shot I got of one at the marsh last Saturday:


I’ve also seen them at the Carpinteria bluffs. (Thanks to William in both cases for pointing them out. Even though I was specifically looking for them, it took my perceptive 11-year-old to actually find them.)

The number of adult beetles on the coyote brush is still pretty small; I saw a few bushes that had 4 or 5 beetles climbing around in one area, but if the vast number of larvae I was seeing in the marsh a month or so ago is any indication, we’re due for a lot more beetles to appear in the weeks ahead.

Marsh Invertebrates

Wednesday, April 1st, 2009

I really enjoy GrrlScientist’s Living the Scientific Life (Scientist, Interrupted) blog (especially the “Mystery Bird of the Day” feature), so when she mentioned recently that she was looking for submissions for the Circus of the Spineless blog carnival, I decided to take a walk at the salt marsh to look for invertebrates, and write about what I found.

There’s a new sign at the north entrance to the marsh, by the way. Wouldn’t this make a cool photo for Mystery Bird of the Day? Can you recognize the bird? It’s a common species in the marsh and on nearby beaches.


One of the first invertebrates I noticed at the marsh during my walk were these shiny green insect larvae, happily munching away on the leaves of coyote brush (Baccharis pilularis).


These guys were on every coyote brush I looked at; I count six of them in this picture alone. I did a quick estimate, and decided that there were about 500 of them on a single large plant. Multiply that by the amount of coyote brush at the marsh, and that’s a lot of larvae.

At first I thought they were some kind of caterpillar, but after posting my photo at, early speculation has centered on the genus Trirhabda, a kind of leaf beetle. Looking at this image of Trirhabda flavolimbata made me remember that several months ago I’d seen a beetle that looked a lot like that all over the coyote brush. According to this entry at, there are at least three species of Trirhabda in coastal California, with T. flavolimbata being the one that specializes in coyote brush.

Update: I took most of the photos in this blog entry during a walk with William on Sunday, March 29. Based on the discussion at, I went back this morning — Thursday, April 2 — with Julia to get some better photos. Here are three that she took (posted at here, here, and here).

This gives you a good shot of the larva’s head:


This shows the larva’s body, as well as a dark fluid on the plant that I’m assuming is related to the larva in some way, though I’m not sure how. Maybe it’s fluid that is draining from the fresh “frass” (insect poop) on the leaf above it?


In reference to that fluid, Charley Eiseman, author of the upcoming book Invertebrate Tracks & Sign, wrote in response to an email I sent him:

If these were caterpillars or sawfly larvae, I might be a little worried about their health, but more “soupy” excrement isn’t too unusual for leaf beetle larvae.

You know, I never expected when I got out of bed this morning that I’d be learning about the consistency of leaf beetle excrement. But I think it’s cool that the larva’s soupy poop actually helps confirm the ID.

Finally, here’s a shot that shows the larva’s prolegs. Some of the commenters at were especially interested in seeing those.


[Back to the original blog entry.]

While looking at the coyote brush, I also noticed this interesting white object:


I wasn’t sure at the time what it was, but I had a vague recollection that led me to google for “scale insect”, and sure enough, this looks a lot like a cottony cushion scale (Icerya purchasi) (and Charley Eiseman, writing at, agrees). Here’s a cropped version of the original image to give you a better look:


My google search led me to’s Cottony Cushion Scale: The pest that launched a revolution in pest control methods. Among the things I learned there:

  • This is a female scale insect.
  • The actual insect is the brownish thing at the upper right, covered by white waxy fibers. She’s attached herself to the plant, and is more or less immobile.
  • The large, white, grooved part extending to the left is not her abdomen, as I originally thought. It’s an external egg case.
  • The cottony cushion scale is not native to North America. It hitchhiked here from Australia in 1868, arriving on a shipment of plants and soon becoming a serious pest in the California orange groves.
  • The scale was eventually controlled by introducing one of its natural predators, an Australian lady bug. When I read that, it reminded me that I’d already read another account of that same event, in Sue Hubbell’s excellent book, Broadsides from Other Orders.

Continuing the list of things feeding on the coyote brush, I noticed this swelling at the end of a coyote brush stem. It’s a gall, the work of an insect that lays its egg inside the plant, leading the plant to create an enlarged chamber within which the insect larva grows:


I had no idea what insect might have done this, though Charley Eiseman responded at that he thinks it was made by a species of midge, Rhopalomyia californica. Looking at some of the other photos at, I think he’s probably right. I’ve been unable to find an image of the adult midge, but Flickr user “Eric in SF” opened up one of the galls and took a photo of the larva.

According to an article abstract I found online (Ecology of Rhopalomyia californica Felt at Jasper Ridge), the midge “is under investigation as a possible biological control agent against related species of Baccharis that are rangeland weeds in Texas and Australia.”

Another type of gall can be seen in this photo. These are in a leaf of the arroyo willow (Salix lasiolepis) growing next to the boardwalk that winds through the marsh’s small patch of coastal dune habitat:


Again, I had no idea as to the species of insect involved, but Charley Eiseman wrote at that he thinks it is a sawfly of the genus Pontania.

As I mentioned, the marsh’s patch of coastal dune habitat is small, but it’s very important to at least one species: the globose dune beetle (Coelus globosus), a coastal specialist that has become rare as coastal dunes give way to houses and condos. Andrea Adams-Morden has pointed out the trails in the dunes to me and told me they were produced by globose dune beetles, and I’ve seen a few dead beetles, but so far I’ve never found a live one. In the meantime, I like checking out their trails, which the beetles leave as they burrow just under the surface of the sand. Can you see the beetle trails in this photo?


Here’s a closeup of some beetle trails. It looks to me like maybe there was a single beetle that entered from the upper right, did a counter-clockwise loop, crossed its own earlier trail, and exited at the upper left:


There’s a neat series of photos of a related species, Eusattus dilatatus, at the myrmecos blog: Friday Beetle Blogging: Eusattus Dune Beetle. You can see the beetle burrowing into the sand, a process that takes about 30 seconds.

One of the best-known invertebrates in the Carpinteria salt marsh is the California horn snail (Cerithidea californica). Millions of these marine snails live in the marsh; you can see them crawling over the mudflats at low tide, and after they die their shells get washed out of the marsh entrance and turn up along the beach at Carpinteria, where I’ve picked up dozens of them during a single walk.

One of my favorite lectures during docent training was given by Dr. Kevin Lafferty, a parasitologist who has studied the use of horn snail parasites as a way of measuring ecosystem health in coastal marshes. I didn’t get any photos of horn snails during my walk in the marsh this past weekend, but I did take some photos of the very cool interpretive sign near the Franklin Creek bridge that talks about the complex life cycles of salt marsh parasites. Here’s a close-up of part of the sign:


If you want to learn more, you can see the image of the whole sign that I posted on Flickr, and click through to the largest size, which should be fairly readable.

One other invertebrate at the marsh, one that’s actually kind of similar to the California horn snail in size and shape, is the decollate snail (Rumina decollata). It’s a terrestrial snail, not an aquatic one. I noticed them crawling across the trail near Ash Avenue one morning when I was walking the marsh with William, and I was surprised, because I’d never seen an elongated snail like that on land before. An email to the carpmarshfriends Yahoo group got me some help with the ID, after which I learned more about the snail at the nice Wikipedia article on it.

Decollate snails are non-native; they originate near the Mediterranean, and are predators who feed on the eggs and young of other snails. They’re used by gardeners as a means of controlling another non-native, the invasive brown garden snail, and presumably that’s how these guys got into the marsh: crawling in from someone’s garden along Ash Avenue.

They’re nocturnal, and so far I’ve only seen them early in the morning after a rain. I couldn’t find any on my recent walk, but I did find this empty shell of one:


Update: When Julia and I returned to the marsh on April 2 to get better photos of the larvae on the coyote brush, we also found a decollate snail climbing in the blue-eyed grass (Sisyrinchium bellum). I really like this shot Julia took of it:


She also got this shot from the other side, showing what looks to me like a thread of some sort emerging from the area of the snail’s mouth. I didn’t notice it at the time, so I can’t tell you anything else about it, but it’s certainly interesting. What’s going on with that?


Thinking about it some more, and staring at the largest version of the image, I find myself thinking a wacky thought: What if the snail actually ate a spider? Could that happen? If it did, could it have left the spider’s dragline extending away from the snail’s mouth? I guess it’s a lot more likely that the snail decided to snack on a stray piece of silk, or just ran into it and got tangled up.

Overall, I had a really fun time rummaging for invertebrates at the marsh. I hope you enjoyed reading about them.