Hornworm frass killing my tomato plants?!

Odd I know.. But has anyone else has this happen? I've had hornworm issues all season, so needless to say there is frass on alot of the lower leaves. Its kind of hard to see all the tiny frass on the leaves but it's there.

Another picture..

You also have holes on the tomatoes, so it looks like they have succumbed! Did you not try to get rid of the hornworms earlier?

I just looked at the pics again, and I can see how it looks like they got into the tomatoes. The first pic has a big tomato in it that one has splits and I hate to admit this but has battle wounds from my 1 yr old trying to "rake" with a hand rake haha! She is a huge fan of the cherry tomatoes and makes her way into my garden all the time! I just cant bring myself to fence it off though. She loves helping in the garden! As for the second pic that little guy still has that thing hanging from it that reminds me of a little umbilical cord haha. About a month ago I did have another plant have a tomato that was being devoured by an inch type worm.

I hand pick them daily. Last week I picked off so many little green eggs, so I only assume the ones I missed are whats eating the the plants this week. I dont use any sort of bug sprays. I have a 1 yr old and a 3 yr old so I chose not to spray just in case they pick stuff off and eat it.

I am no expert ... but I followedhe suggestion from a fellow farmer.
He told me to add one maybe 1 tbs of DE on the planting hole of the tomatoes when I transplanted them out !!
It has been 2 years in a row that I did this and I had only 2 hornworms all season on more than 30 tomato plants ... even now that my spring tomato plants are just seating out there waiting to be removed I don't see any hornworm ... which NOW it will sure a great help ...
So I will do it again next year. Maybe the tomato plant absorbed the DE and it changed taste. I dunno.

drthor, sounds interesting. Although i'm not sure what DE is. This is my first year gardening so i'm still learning what is what haha.

Googlie..."DE" is diatomaceous earth, a fairly safe product for soft-bodied pests.
It works as a contact repellent/killer and pest have to crawl in it or have it sprinkled on them to have any affect. Putting it in a hole as Drthor suggested might repel caterpillars/worms but seems to be a big waste of money to me...but then I'm a miser!

Back to your original question...caterpillar frass won't kill your plants, only the caterpillars will by eating the foliage. I don't see any foliage damage from c-pillars in your pic. However, I see cupped leaves, dried leaves, and those are certainly not the result of a bug/insect, etc.

The worm(s) eating your tomatoes are most like tomato worm. If you dust with Dipel or continue to hand pick that will help. The Dipel will be of greater benefit as long as you dust the plants before the worms enter the fruit. Once inside there is not much you can do.

Hope this helps.
Shoe

Ok after looking at the pictures really closely I see what might be thrip damage on the leaves. White lines/dots with black specks and in the second picture the tomato on the left appears to have insects damage. Thrips saliva can damage the foliage as well as simply feeding on the foliage by piercing the leaves/fruit and sucking out the juices. They also carry the Tomato Spotted Wilt Virus (TSWV),but even without the virus they can do plenty of damage.

I agree with Shoe. Hornworm frass is dark and bullet shaped and doesn't destroy foliage, and I don't see that on the foliage, which speaks to me more of a foliage disease rather than any frass problem.

Carolyn.

Shoe, thanks for the DE explanation. Where would I purchase said DE? I'll get you some different pics today. The tomato plant in that pic has had curled leaves like that since day 1. It as probably one of my very first posts on the tomato forum some time ago. I think the most I got out of that thread was that it can be normal for some types to curl? http://davesgarden.com/community/forums/t/1190120/
As for the caterpillars eating my tomatoes.. I actually dont have that problem..yet. I came across this inch type worm about 2 months ago that made its away into a tomato. But that is the only incident like that, that i've had. I tried identifying it a while back so I made a post about that too. Haha! http://davesgarden.com/community/forums/t/1196883/

1lisasc, I never thought about thrips. I'm going to look my plants over take more pics and google everything.

Carolyn, its so hard to see the frass in both the pics but I promise you its there. On just about every leaf from the middle of the bush down. In the second picture there is some that fell off the leaf onto my hand. I think its time to upgrade my camera. haha! With that said im not throwing out the disease possibility just yet. New pics to come:)

Okay I came across a picture on google of what my plant looks like exactly!! They think its possible its spider mites. http://forums.gardenweb.com/forums/load/tompests/msg0513183814387.html?9

Look at the picture they posted. there is a link just under there post called "lower leaves turning yellow whiteflys/aphids".

I'm pretty sure what I think is hornworm frass may not be that at all. Anyways I took a million pics that im about to post so you can get a good look.

Here you can see just how bad of a hornworm and inch type worm infestion I have/had. Pretty sure I have picked most of them off now. I only found 1 this morning on all 4 of my tomato plants. So needless to say from the middle down its covered in frass, AND possibly what isnt frass?

The entire plant. The curled yellowing leaves you see are the ones covered the black looking frass (is what i'll call it!). Those leaves are also the leaves I originally posted about ages ago that were curling that I assumed were normal.

Googlie4gardens, you can buy your DE (=diatomaceous earth0 at your garden store. it is just a little bag.
I just apply the DE on the planting hole (under the roots) when I transplant out my tomatoes.
I really cannot explain why ... but the farmer that told me this recipe was right.
Only two hornworms a year !!

Googlie, I can't see any frass at all in those pics but maybe it is either my eyes or my monitor.

Could the black stuff you're referring to be what's referred to as "sooty mold" that is usually produced by aphids? Scale will also leave that behind.

Shoe

Spider mite damage looks a lot like thrip damage. I just found this out doing some recent research. Do you see any webbing? Thrip damage can cause white dashes and black dots. You may want to google it. Both like hot dry conditions. The little marks on the fruit in the second picture doesnt look like SM damage but maybe thrips?

Your first post said youve had a hornworm issue, but then you said you havent seen any hornworms. Im confused.

I see what looks like Spider/russet mite damage in the first 2 pics. It's the time of year in SoCal to see mite populations explode. I'm letting my plants fend for themselves these days and the mites are really taking them down fast. The faster they kill them, the faster I can focus on cool weather veggies :)

The poop you are seeing is definitely not hornworm poop. Unless babies. Nor do I see any hornworm stripping from feeding. Looks more like looper and possibly armyworm damage.

Hornworm poop pic for you below :) They look like grenades and bigger than rabbit droppings. So, it looks like you have a lot going on. A smorgasbord of bugs. That's pretty normal for August and September in SoCal.

EDIT: Lisa brought up thrips, which is a good possibility as well. I've had a battle with them a few months back for the first time ever. I won, but took time....weeks!




This message was edited Aug 22, 2011 4:15 PM

After seeing that link earlier, I think I have come to the realization that, that isnt hornworm frass. But frass is all over my plant none the less. I think it was so hard to distinguish that bc I pluck my hornworms daily so I have never had hornworms big enough to drop poops that big haha! How gross was your picture though haha! I didnt know it it could get that big! Im leaning towards thrips after googling it a little bit earlier. But I have to google it some more still.

drthor, 2 hornworms a year is pretty impressive! I dont know much about DE, I gave it a quick google. But from what i have read I think I will invest in some next season! I'm almost about to let my garden go after all this nonsense.

Shoe, You were right its not frass. So your eyes and monitor are fine ;) But its also not mold. I have yet to see any aphids either :/ What is scale? Is that another insect?

1lisac, Now you have me confused lol. I'm not sure where I said I havent seen any hornworms. I have a hornworms no doubt about that. But im completely leaving the hormworm issue out of this now... since i have learned that the black stuff on the leaves are not frass. There is a web, but I know for certain its not spidermite web. I have no spider mites that I know of. Although im not out there with a magnifying glass either. The main stem is the only part of the plant with those yellowing leaves that have what looks to be black dust (not frass:) of some sort. Can I just chop that main stem and see what happens? The plants new growth on one side of it looks amazing!! I'll post a pic. But if you look from another view at the main stem it looks terrible (i'll post a pic of that too.) And it looks like a new stem is growing next to it.

Ray_Der_Phan,
Did your leaves look like mine when you had your thrips or spidermites. Can I have spidermites but no webs? Or did you have any of that black stuff on your leaves? I dont have armyworms. My worms are hornworm and cabbage looper. I did come across some tan eggs as well as a tan baby worm this morning. Dont know what that guy is yet, but I imagine i'll have an outbreak of that soon too. Just cant catch a break right now lol!

Side view of tomato plant and of all its new growth looking nice!

View of main stem. See the little one next to it. It even has a new tomato on it. I'm sure your also wondering what happened to the bottom of the main stem... it couldnt handle the 4 tomatoes that were on it and broke :/ This was before I started with the A&M ribbon. All the other blunt looking ends were where yellow leaves were at some point in the past week.

Despite all this the plant has 19 tomatoes growing on it and they all look fine. No damage beside some cracking on a few of the bigger ones.

Ok forget the horned worms, I must have misunderstood. If you see webbing how do you know it's not SM that would be my first clue. What do you think it's from, then. Just wondering. This is the year that I realized that most, if not all my veggie diseases, are actually pest damge but it's hard to tell what from what since TX has soooo many pests : )

Hope that last post didnt sound snotty. If it did sorry! I know its not SM bc the web is a spiders web. I have 2 actually. One in the peppers and one in the tomatoes, and I have seen the spiders many times. If I read correctly spider mites dont have long stringy webs but more clustered type webs? I was looking over my plant this morning and I do in fact have some sort of infestion that looks to be very tiny wingless tanish colored things on the underside of all the "infected" leaves. Which is making me lean towards aphids? They are much smaller then any aphid i have seen on roses, so i'm assuming they've just hatched I'm going to use the insecticidal soap i've been resisting for so long and see if that doesnt help. I also met someone at the farmers market yesterday who said they were willing to come check out my plants!! I see a bit of relief ahead, whether it be the plants recouping or me ripping them up haha!


Thanks for your help everyone!! I hope I haven't been too much of a pain :P

You have spider webs not webbing. I don't think you're being a pain, I'm as interested as you are to find out what this is. Please let us know what you find out. One easy way to look at the little critters is to put a white piece of paper under an infested leaf and shake the leaf so the critters fall on it. This makes them much easier to see you cane even use a magnifying glass to get a better look.

Don't use the insecticidal soap in the heat of the day. I would apply it in the evening so it will be dry when the sun does come up, otherwise you are going to have a whole other set of problems. Please keep us posted.

Thanks for the white paper idea!! While googling I kept coming across pics of people holding white papers under their plants but couldnt figure out why! DUH haha! I'll make sure to douse the plants at night! Thanks for the heads up! I'll let you know in a week or so what I have come up with or if I still have any plants. Thanks for all your help!

I hope you have the person come by to help you out. Maybe you can get a picture of the bugs you are seeing. If you get some on a paper maybe you can show them to the person who offered to come to your house. Depending on what type of pest might also help identify if there is disease since some viruses are spread by specific pests. Please find out the suspense is killing me. You know us Texans love our bugs, or we couldn't live here!

Haha! I was just saying how much I missed all the bugs in TX bwahah! Or at least the nightly orchestrated music they put on. I'll see if I can get some bugs on the paper today, if so I'll try and snap a photo for you :) Hopefully i'll be meeting up with the garden guru (as i've been calling her) this afternoon. I may even be making her grandbabies some tutus in exchange for me picking her brain :P Updates to come!