Small green caterpillars, black flies with red heads, tunnel damage - Answered

Aim:

I've returned from Joplin. Lots to tell about the tornado and the destruction it left behind. I will save that for another day. While I was there, Mom asked me to take a look at her hollyhock in the back yard, which has some problems. For one thing, its lower leaves are all eaten out.

I found the culprit fairly quickly - caterpillars. They are very small and well camouflaged, so Mom had missed seeing them without her glasses. Here are some pictures. It's sort of like Where's Waldo. We counted at least 7 in this photo:

Here is another picture of one caterpillar actually chomping on a leaf:

We picked all of them off and squished them by hand. Well, I squished them and Mom said "eeeew." I find it oddly satisfying to squish them, but I'm pretty sure Mom would prefer a remedy that does not involve green goo on her fingers. Perhaps beneficial predators? I was wondering if lacewings would do the trick.

Black Flies
The caterpillars are not alone. In addition, there were at least 6 or 7 of these black winged bugs hanging out on the plant as well:

The hollyhock may serve merely as a singles bar for these bugs, though, as they appeared to be doing some dirty deeds with each other:

We don't know whether they are eating foliage, or eating the bad guys, or merely mating (or farting on each other, because frankly that's what it looks like). Thoughts?

Tunneling
Aside from the caterpillar damage, there are also several discolored tunnels on the foliage with no visible culprit. It looks like trails left behind from a wiggling creature, but the discoloration almost seems to be embedded in the leaf rather than on top of it. The trails are not stains on top that you can wipe off. If you lift the leaf up to the sun, more light comes through the discolored tunnels than through the undamaged leaf part. I've never seen this before. What do you think?

White insect husks
This hollyhock is home to an entire ecosystem. I kept examining the leaves and finding more insects. Another potential concern were several white insect exoskeletons perched around the plant. They are no longer alive, but since there were so many of them (about 5) it caused me to wonder whether they had turned into something else.

I am not as concerned about these given that they are dead and therefore incapable of doing additional damage to the plant. However, I've never seen them before and would like to know what they are. Did they give birth to the caterpillars?? Are they related to any of the other creatures who call this hollyhock home?

Love,
Rachel

Answer

Rachel and Mom,

I was all set to write a post on the wonders of Bt, because it is the best organic control for caterpillars. BUT. Looking at the pictures, it seems the first two culprits are the same thing: Sawflies. I think it's the Black-Headed Ash Sawfly, if we want to get specific. So Bt wouldn't work, because these guys only look like caterpillars. Rachel, you won't encounter this species in Seattle. They range from the east coast to the great plains. You might encounter another type of sawfly, though. Sawflies are in the Order Hymenoptera, which is generally a helpful order including bees and parasitic wasps. But these guys are pests. The grubs skeletonize leaves, like you see here, eating everything but the leaf stems. Some people call this windowing, but that technically applies to a different type of damage. Other species of sawflies can mine or window instead. The Black Headed Ash Sawfly really likes ornamental plants and shrubs. They're gregarious, meaning they often line up 5-6 in a row while feeding.

Here's a picture:
They have black heads in the larval stage, which are visible in your pictures. Most of them I've seen have whitish, clearish bodies - like those to the left. I think yours are green because of how much hollyhock they've ingested. But the black heads are clearly visible, and the damage fits. You also caught the adults both mating and ovipositing on the leaves.

Here's an adult:








Established plants can handle a surprisingly large amount of sawfly damage. These are attacking the lower leaves and leaving the upper foliage intact, but the damage is a little worrying. They have a lot of natural enemies, which usually provide sufficient control. For whatever reason, there don't seem to be many natural enemies preying on these guys. You should probably order some lacewings to release, and they'd be good for your entire yard/garden anyway.
http://www.gardensalive.com/product.asp?pn=5030

Yellow flowers in the area might attract some parasitic wasps and syrphid flies. The adults feed on the nectar and oviposit nearby if they detect prey. It's not a guarantee, but it doesn't hurt either. Meanwhile, picking the sawflies off and squishing them is a good idea. If that's too icky, you could simply remove the damaged leaves with larvae on them. Don't use any broad spectrum pesticides, because that also kills the natural enemies. The sawfly population will likely bounce back well before the natural enemy population. So pesticides can actually make the problem worse. If you know you're going to lose a given leaf, you could apply an oil. Don't do this on the whole plant though, because that will clog the plant's stomata (or breathing tubes) and kill it. But if a given leaf is already pretty much gone, oil is an alternative to picking them off. It could also trap some of the adults who land on the plant. You might even try knocking them off with water from the hose. Don't know if it'll work without damaging the flowers, but it's worth a shot.

Tunneling
That's some kind of leafminer, but I can't identify it without seeing an adult. It's probably some type of fly, but there are lepidopteran (moth) and hymenopteran (other species of sawfly, etc) miners too. It doesn't matter, though. Leafminers rarely cause damage. Well, they cause cosmetic damage, so commercial outfits hate them, but they rarely hurt a plant. I wouldn't worry about it unless they start killing leaves. I highly doubt that will happen. I kind of think the mines are pretty, but I'm weird that way. Just FYI, spray pesticides rarely work on leafminers. As you noticed, they're inside the leaves. There are systemic pesticides (that were supposed to be safe) but we're finding out they destroy bee populations. (Well, the data has become so convincing that even the pesticide companies are starting to acknowledge it). So it isn't good to use them on anything that blooms. If you really want to get rid of leafminers, best to dig them out. Treat the mine like a maze and follow it to both ends. One is the beginning and the other is the end of the path. They only go forwards. If you find a largish hole in one end, then you're too late. The sucker has already escaped. If not, scoop out both ends and you'll likely get the larva.

White Insect Husks
Close guess, they are what the larvae turn into. I think these might even be the sawfly pupae (or cocoons). But I've never seen a pupa of this species. If so, you captured the entire generation of sawflies in pictorial form! The adults do their "dirty deeds" (as you put it), and the female deposits the eggs on the leaf. The egg hatches and the sawfly larva eats and eats and eats. Then it pupates - or builds a cocoon and stops doing outside activities to focus on changing it's entire body style. When it's done with that, the adults emerge to use the hollyhock as a singles bar again. These are the casings left behind after the pupa emerge to adults. Mom, if you see any of these that aren't empty, kill them too. They're kind of cool to pick up and see if they'll wiggle for you. But they don't have mouths or the ability to poop on you either. That way you'll have fewer adult pests in the area. Incidentally, did you notice all the little black dots on the leaves? That's frass, or bug poop.

Love,
Aim

Addendum: Syrphid Larvae are natural enemies
In answering Laurence's question about sawflies in Alaska, I talk about syrphid fly larvae - an important natural enemy. I haven't seen these predators covered as much for home gardeners, and they could be confused with sawfly larvae if you aren't looking for them. They are voracious hunters, and will help control aphid populations as well. The adults will pollinate your flowers and the immatures will help control all manner of pests. So I've added some pictures.

Here's a picture of the generations of syrphid flies


Here's a picture of a larvae, chomping on an aphid


And here's another picture of a syrphid fly larva.

If you see these on any plant, leave them. They're pretty awesome.

Joplin Tornado

Amy and I (the authors of this blog) are from Joplin.  On Sunday, a massive tornado destroyed most of the town.  All of our relatives live there - our parents, grandma, aunts, uncles, cousins, second cousins.   My grandma and cousin Amber each live in the section of town that was obliterated.  My aunt Rayma and cousin Trisha were in St. John's hospital when the tornado slammed into it.

But we were lucky - everyone in our family survived. 

I mean lucky as a relative term.  My cousin Amber and her husband Dustey made it to the basement and held onto their 3 young boys for dear life while the entire house blew away above their heads. When the storm passed, they literally walked away with only the clothes on their backs.  Even their washer and dryer had disappeared.

Amber's strength of character showed through in her Facebook status the next day.  She wrote:  

"just saw on tv we have had 6 inches of rain in the past few days. at first i was worried about my roof leaking as it was in need of replacing. then it came to me, there is no roof at all, nor is there a house for it to cover. no need to worry then i guess."

Many of our friends and acquaintances have asked how they can help.  Rather than collect physical items to ship from far away, we set up an online fund for donations Amber and Dustey.  We thought it would be easier than gathering up a whole bunch of gift cards.  It will help them re-stock on items needed immediately:  clothes, shoes, food, toiletries,  plastic bins, new underwear and socks, towels, other household items.  

You can donate to this Paypal account for Amber and Dustey:

Standing at the north edge of Amber's yard looking south/southwest. That's the front bedroom still partially standing.

 Looking east toward the house

 Between Amber's house and the neighbor

The house

Looking toward Amber's house from across the street.

They used to have a garage on this concrete slab.

Cleaning up

Soil Centipede Attacking Wireworms

Amy:

You mentioned that the orange soil centipede is a predator and might be eating the wireworms, since they are all hanging out in the same corner of my garden.  This week I pulled one of the carrot decoys up and found not only a wireworm, but an orange soil centipede going after the wireworm:

Between the centipedes and me killing the wireworms in the carrots, I don't seem to have hardly any wireworms left in the garden now.  Pretty cool!  I'll probably keep the carrot decoys around the garden throughout the growing season and see what happens with the populations.

--Rachel

Beautiful Beetle - Answered

Aim:

I finally completed a major garden project today. I used to have gravel walkways between my raised beds, but over time, the barrier fabric underneath stopped suppressing weeds. Last year and this spring, dandelions overtook the gravel, and their strong taproots grew straight through the fabric. Today I tore it all up and planted Corsican mint, a spreading herb that you can walk on. Added bonus: it releases minty air freshener every time you step on it.

As I was disturbing the rocks and soil and dandelions, I turned up some creatures. Notably, a fair population of roly-poly's, plus this purplish beetle.

You can see both in the picture above. I took this additional photo, mostly because I know how much you like beetles. (Don't you have a coffee-table book with photos of beetles that look like jewels?)

Although very pretty, I wonder whether the beetle is good/bad/indifferent to my garden? I found it in the pathway, not feeding on any vegetation. So, I did not kill it.

Also the roly-poly things. Again, they were in the pathway, not my actual beds. Are they detrimental, or a sign of something else that is bad?

--Rach


Answer

I'm not sure what kind of beetle that is. There are a lot of beetles. When someone asked the scientist J.B.S. Haldane what he'd learned about the Creator from studying His work, Haldane replied that God has, "and inordinate fondness for beetles." There have been over 350,000 species of beetles described (slightly more than 4 per day since we started keeping track in the 1700s). And my favorite statistic: if every plant and animal species in the world were placed in a single file line, 1 out of every 5 would be a beetle. They inhabit pretty much every habitat in the world. And, yeah, I have a coffee table book that's full of pictures of them. But I'm not very good at identifying them by sight, except for some of the usual suspects. I especially like the Clown beetles that do handstands when disturbed and aquatic whirligig beetles.

That said, I think you have some type of carabid there, which would be a good thing. The first picture looks like it has fused elytra (the hard cap on the back of the wings), which points to a carabid. There are about 40,000 species of carabids world wide, and at least 4,000 in North America. They're called ground beetles, and several species are cosmopolitan (meaning they don't seek out humans, but they thrive in areas with humans). They're primarily nocturnal, and spend the days under bark and/or rocks. Good news: if it's a carabid, it's probably eating your slugs. They hunt at night, so you wouldn't be able to see them in action unless you brought out a black light and looked for them. I might be wrong, so keep an eye on your plants. But I'm pretty sure it's a good thing you left it alone.

Roly Polys (or pill bugs or sow bugs) are often blamed by home gardeners for damage caused by other pests, because they are so ubiquitous. I was reading a forum about slug damage, and several people swore the damage was caused by these (pill or sow) bugs. Nevermind that their little mouths are waaay too small for that. They feed primarily on decaying plant matter, so you'll have them in any garden that uses a lot of compost. They're very good to have in a compost pile. They have been known to feed on seedlings, which is why some gardeners blame them for damage. If you catch something chomping away, you assume it's causing the harm you see. But unless you have a ridiculously huge population, they can't do much damage to a plant. You won't see them stripping a garden. Usually, it's the case of a sick plant (due to other culprits) where the roly polys get in on the fun. Because they feed during the day and are recognizable, people blame them. Fun fact: the scientific family name is Armadillidiidae, because they look like little armadillos. Dorky fact: I used to play bug doctor with roly polys at Grandma's house: they were sick when they curled up, and I had healed them when they started walking around on my hand.

In conclusion: I think both the beetle and roly polys are a good thing to have in the yard. Let me know if you see the beetle over by your garden, because I could be wrong in my identification. My guess is that you only saw her because you were redoing the path.

Lacewings & Lupines

Amy:

Remember my first post on this blog about a leaf curl problem in my lupine?  Couldn't figure out exactly what it was, but you sent me some lacewing larvae to sprinkle around it.  I'm happy to say that solved the problem.  After applying the larvae, my lupine recovered within about 3-4 weeks.  This spring, it has emerged free of problems.  I still am not sure exactly which pest was curling the leaves, but whatever it was, there's no more leaf curl.

For anyone else out there with this problem, try lacewings!  http://www.gardensalive.com/product.asp?pn=5030

Here's my lupine this spring:

Skinny Orange Soil Dweller With Many Legs - Answered

Following up from my April 10 post, I took a closer look at the skinny fast-moving orange thing. Its whole body is segmented and it has legs along the entire body. This picture is not stellar, but it's the best I could do:

You can kind of see its legs here. Like I said, I don't have a ton of them. But I did find 2-3 in the same corner of my garden with all the wireworms.

They are somewhat creepy. They curl into S's real fast sometimes when moving around.


Answer:

I am very glad to hear that there are many legs. Otherwise I'd be at a loss. The many legs indicate either a centipede or a millipede. Neither one is a problem. Millipedes have 2 and sometimes 4 pairs of legs per segment. Centipedes have only one pair of legs per segment. I can't really tell from the picture, and I doubt you want to get close enough to check. Whichever it is, it's probably good that you have them.

Millipedes are usually beneficial to a garden. They feed on rotting leaves, wood, and help break down decaying plant matter. They are (generally) slower moving and curl into a characteristic C shape when you mess with them. When walking, their legs kind of undulate like a wave moving down the body. If you have a really large population, they have been known to damage seedlings. But this is pretty rare, and you don't have a ton of them. I don't think this is a millipede, anyway. Though I'd like to get a closer look at the thing that was curled into a C from the video you took. It could be a pill bug, a millipede, or even a cutworm.

Centipedes are generalist predators. They do move very quickly, and they don't curl up into a C-shape when disturbed. The fact that this thing is still running around when you have it on a new substrate makes me think it's a centipede. They lay eggs in moist soil in the spring, so you might simply have a hatching. They also might be feeding on the wireworms, since there is a positive correlation between the respective populations. Anyhow, they never damage plants. They might eat a few of your lovely earth worms too, but that's the worst harm they will do. When found inside a house, a lot of people immediately go into "Oh my god; kill it! Kill it now!" mode. Especially since some house varieties have really long legs. BUT. They eat cockroaches, flies and other pests. And they usually like dark and dank places - like basements. So if you can stomach it, it's better to leave them. Don't pick these up with your bare hands, because they have powerful jaws and some possess a mild poison. Seriously, one of the keys to determining whether you have a centipede or a millipede is, "attempts to bite." So well-meaning people who try to remove them from the house (rather than killing or leaving-be) can be in for a nasty shock.

Either way, I wouldn't worry about these critters. Millipedes are indicative of healthy soil and centipedes are creepy little warriors on your side.

The Carrot-Trap for Wireworms

You recommended burying carrots or potatoes around the garden as a method to attract and dispose of  wireworms.

It totally works.

I used grocery-store carrots.  I cut them in half, because the ones I had were ridiculously long. I pushed them into the soil at various points around my garden, leaving a "handle" sticking up above the soil.

I left them alone for a week.  It rained a lot during the past week, which encouraged decay.  You had said that wireworms like soft, decaying veggies.   Today I checked them.  The first one I pulled up was riddled with holes and had three writhing wireworms.

I picked them out of the carrot, threw them onto the driveway nearby and stomped on them.  I checked the other buried carrots and did the same thing.

I also now know which part of the garden the wireworms are concentrating.  The carrots in one corner of my largest raised bed were the most ridden with wireworms.  The further away I got from that corner, the fewer worms.  In fact, the carrots in the far opposite corner had no wireworms.  Interesting.  The infested corner is the area where I had my peas and tomatoes last year.  The area of last year's kale and escarole had the fewest wireworms.

Thanks!

Shovelful of Soil

Aim:

I pushed a shovel into my garden soil today and went through it with my hands like a mother goes through a head of hair for lice. For starters, I was looking for symphylans. If I have them, I might make some evasive maneuvers this spring. Maybe even move my garden.

Looking through the soil was really interesting. When you look at soil closely, it's like peering into a miniature universe. The soil is literally crawling with stuff. The big elephants of the garden are earthworms. All the organic matter I build into the soil attracts them, so I not only spotted them in quantity but saw a few monsters as well. (Remember when Abby had the Pet Parade at Stapleton Elementary, and since Mom told her she couldn't bring the cat, she proudly paraded with a styrofoam cup of earthworms?)

In one scoopful of soil, I found some things that concerned me. I saved three of them and captured them on video in the hope that you might help me identify them and figure out whether they're good, bad or neutral.

The larger, slow-moving orange thing - I have a lot of those. Not as many of the skinny fast one with antennae. But a couple of them in one section of the garden. Also a fair amount of those gray, coiled things (look in the upper-right-hand corner of the video. Thoughts on what they are?

--Rachel

Answer

So is this a new and exciting use for the GoPro? I approve.

Larger, Slow-moving Orange Thing: Wireworms

I'm almost positive that's a wireworm - or click beetle, if you're talking about adults. They're pretty common in the spring and fall, and in newly turned earth. The bad news is that they like to attack the root system of plants, causing stunted growth or even death. They'll also bore into tubers. You see them more in the spring and fall because they like cooler temperatures, and will burrow deeper than your plant's roots in the hot part of summer. Were you planning on planting soon? Cause it might be best to wait a bit and deal with them before putting in vulnerable seeds and seedlings. They do most damage to plants at those stages. Pesticides don't really work on them, but this is one of those happy occasions where cultural and biological controls work pretty well.

Bury some carrots and potatoes
They like carrots and potatoes a lot. So, you can use them as traps pretty much immediately. I'd buy some of each and bury them in regular areas around the garden. Just push the carrots into the soil so that they mimic a growing carrot. Cut the potatoes in half and then push a stick through them. Bury them at least an inch or so under the soil, with the stick above like a handle. Every few days you should pull them up and check for wireworms. Remove any that are there, then stick it back in the soil. This is a good thing to do throughout the growing season too, since soil temperatures in Seattle are probably still pretty low. You might find some Symphylans on these at this stage too, but you should take their presence with a grain of salt. There are several species of symphylans that prefer decaying vegetation, and they're beneficial to the eco-system. The species of damaging symphylan prefers to eat living plants, so you'd want to look for those in the roots of your grass or weeds. But they might appear on your potatoes when you don't have much planted - like right now. The nasty ones can't actually burrow into the soil on their own, so they need to follow soil that has been upset. So also look for them in the top layers of soil. I have some suggestions for Symphylan maintenance, if you find them in the area.

Beneficial Nemotodes
I'd also recommend that you invest in some Grub-Away Nemotodes. They attack a wide variety of soil pests, and we think you've had cutworms too. This is an organism, so it's a form of biological control. Therefore you don't have to worry about the good things in the soil, either. You can get 10 million of them for $30.
http://www.gardensalive.com/product.asp?pn=5000
I'd apply them when you are planting. And then maybe again later in the season.

Skinny fast one with Antennae: I don't know yet
Does it have legs? I can't really tell from the video. It moves as though it has legs (at least in the front), but then it's posterior isn't moving at all. And if it has legs, are they only at the front or are they on every segment? If it has legs on every segment, then it might be a type of centipede. Centipedes are predators, so you don't have to worry about your plants. They might be eating some of your earthworms in addition to the pests, though. I usually just leave them alone. If it doesn't have legs (or only has them in the front), then it isn't something I've encountered before. I'll have to research that a bit more.

One at the top right: I can't really see this one at all. A few questions: does it have a hard or soft body? Does it have legs? If it has a soft body, this might be a cutworm. If it's hard and segmented, I'd guess some sort of Isopod (big roly-poly). They may or may not like to chomp of your vegetables. There aren't that many things that curl up like that, so it should be easy to figure out what it is with a little more info.

Aim

Waiting for spring

We had a great time staying with you and Doug this weekend.  Very wintery and snowglobey at your treehouse.  Tubing was, well okay, a little anticlimactic.  But I have some good mental photos of the 4 of us hanging on to each other inner tubes and flailing down the not-very-steep slope fake screaming all together.  Doug made up for it the next day by taking Carlos and me down a steep hillside of fresh powder.  Screaming for real on that one.

Back in Seattle last night, 45 degrees felt really warm.  We are entering the long, wet limbo period that counts for spring in the pacfic northwest.  Not very cold, but not warm either.  Slug heaven.  My hellebores are blooming pink in the back yard and the lilies and crocuses are sending up shoots.  We still have a long way to go before summer, but the garden can support cool weather veggies.

Inventory:  overwintered broccoli, corn salad (mache), escarole, swiss chard, collard greens.  Not a whole lot of any one of those, though. 

Time to start thinking about starting seeds and prepping the garden soil.  My current concern is symphylans.  Apparently, in the pacific northwest, almost any garden plot more than 3 years old becomes totally infested, because they love the soil fertility.  I think I have them.  I know I've seen tiny white centipede things in my soil.  Any advice?  Since I have raised beds, moving my garden plot would be a real hassle . . .