Caterpillars Eating Rose of Sharon

[pinksand]

I have about 20 large Rose of Sheron shrubs being devoured by caterpillars. A lot of the upper leaves have been reduced to the veins. I was out tonight as the sun went down and suddenly the ROS seemed to be covered in caterpillars! Aha confirmation of my suspicions.

What do I do?! My first thought was neem oil, but the little spray bottles I've seen in stores will be a nightmare to use on 20+ large shrubs, not to mention the reapplication after rain, etc. PLUS, I feel bad the caterpillars turn into the butterflies that I LOVE watching dance from bush to bush. However, I'd like to keep my bushes alive and they're looking pretty rough...

Any advice!?

[applestar]

Only butterfly caterpillar that eats Rose of Sharon that turned up in my search was Gray Hairstreak. I see them often in my garden, but I never noticed them eating my RoS but they use other plants for larval host too.

Those are tiny butterflies and presumably the caterpillars are tiny too. Do they do that much damage? Rose of Sharon is a huge pollen source and the blooms are constantly visited by bees and wasps that practically bath in the pollen (as well as all different butterflies and hummingbirds too).

Personally, I wouldn't spray with any insecticide -- there's too much risk of harming the beneficial and desirable visitors. I'd let Rose of Sharon sustain considerable damage -- they are tough and will recover.

Besides, it's almost end of the season for the Rose of Sharon. They are starting to yellow and shed leaves here. First to lose leaves in fall and last to break bud in the spring.

[pinksand]

Thanks for the reply applestar. If you think the RoS can take the damage then I'm fine with going that route and just letting the caterpillars be. I love watching the variety of pollinators that visit the bushes in the Summer, which is why I've put it off for so long. I just couldn't come up with a good solution that wouldn't harm the friendly visitors.

They've really done a significant amount of damage. It's literally twigs and leaf veins on the upper half of the majority of the RoS. A few blooms are still hanging on, but I'm just starting to notice some yellowing of a few lower leaves (there isn't anything left to yellow up top). They may be little, but the caterpillars were all over the bushes! It looked like the twigs were all moving at first and then I realized they were little gray caterpillars.

If you think they'll be fine, I'll leave them be and just give them a trim come Spring.

[rainbowgardener]

You didn't say much about what the caterpillars look like. This is a picture of the caterpillar of the grey hairstreak butterfly Applestar mentioned:

[img]https://bugguide.net/images/cache/CKGKVK8KPKVQB05QD0AQHSUQRSAQZS5KHS9QVK8KOK8KHS4K30MKTK1QBKNQ108Q10PQD0RKUKQKOKMK30UQLS8KWK.jpg[/img]

Is there any particular kind of butterfly you are seeing "dance from bush to bush"?

Wow, 20 RoS, you must have a lot of space. I have one (no two now, since one volunteered it self on the opposite side of the house). But I'm surprised, nothing has ever bothered mine. I think of them as exceptionally tough and carefree. I do think they can withstand a lot of damage, especially as Apple said, this time of year when they are getting ready to drop those leaves anyway. Mine is still blooming, hasn't dropped any leaves yet, but I know that won't be true for much longer.

[pinksand]

It looks like the gray hairstreak caterpillars are green, wide/flat bodied guys (like your photo RBG). The ones I saw last night (although it was getting dark) appeared to be gray/brown and more narrow/round bodied... I'll have to check them out again tonight so I can give a better description. I know they weren't super hairy, but I'll have to check them out again to see if there was any hair at all.

I don't know my butterflies, so I just did some searching on the colors I've seen and body shape and I believe we have lots of Eastern Tiger Swallowtails, maybe black swallowtails, and little white ones (maybe cabbage white). I feel like I may have seen some coral hairstreaks in there too maybe? Sorry, I'm feeling so useless!

I've also seen many different caterpillars, and even some cocoons around the garden. Maybe I should start paying attention and looking them up! We've had everything from big hairy guys to small green ones. We have a ton of moths too of course!

We're on a little over 1/3 of an acre so we've got some land. I probably pulled about 15 baby RoS popping up while I was out there yesterday. I really enjoyed them during the summer but right now I'm hating them between how ugly they are right now from being eaten, and all the baby plants that I can't keep up with! I wish the caterpillars would eat the baby RoS! Then both problems would be solved!

[applestar]

Well, if you can reach them, just pluck them off and put them on the babies. If you don't want to touch them, most caterpillars will crawl onto something placed in their path if you "goose" their behind by poking with fingertip or grass blade, stick, etc. If they squirm in protest but won't move, just goose them a couple more times.

[pinksand]

Well now that's an idea! I guess that if the RoS do get destroyed I always have their backups sprouting up that could replace them

[pinksand]

I got photos!

Headshot
[img]https://i1186.photobucket.com/albums/z379/pinksand11/Garden/Caterpillar1_zpseade4f79.jpg[/img]

Back
[img]https://i1186.photobucket.com/albums/z379/pinksand11/Garden/Caterpillar2_zps8943ff23.jpg[/img]

Caught in the act
[img]https://i1186.photobucket.com/albums/z379/pinksand11/Garden/Caterpillar3_zps4a093034.jpg[/img]

The damage
[img]https://i1186.photobucket.com/albums/z379/pinksand11/Garden/ROS-Damage_zps0777ef97.jpg[/img]

Any idea what kind they are? Do you think the bushes can handle that kind of damage?

[applestar]

It appears to be a moth caterpillar:
https://bugguide.net/node/view/133749/bgimage

It's a beautiful caterpillar though.

I honestly think your rose of Sharon will be fine and grow back next year stronger than ever. The plant is ridiculously vigorous, imho, especialy since it's not native here (it's from Asia) and has few pests to bother it. But I'll read up some more on this moth in case I'm wrong.

Ah ha... It's an introduced moth from Asia. Happily chomping on what it recognized as food.

[pinksand]

That's definitely them! Too bad they aren't going to be pretty butterflies one day they aren't even cute moths. I will let them be. They must feel so at home on their native bushes in this foreign land

[Lingweni]

It's possible those are the larvae of sawflies - my giant hardy hibiscus bushes get them every year.
In my case the sawflies larvae don't turn into butterflies, they turn into more sawflies! A most effective way I found to get rid of them, although gross, is to squash them using paper towel (wearing rubber gloves). Neem oil may help but that'll take time and persistence. I am trying both this season.