Squash Leaf Problem

[GoDawgs]

Yesterday while I was watering I found this fungal or whatever problem on one of the two Butterbush plants. They're young, 18 days out from germination with each having two 5" wide leaves, both of which are funked up. The several younger leaves are clean... so far.

Front of leaf:



Back of leaf:



Leaf petioles were clean. There seems to be a whitening along the edges of the main veins. I checked photos online last night and it doesn't seem to be septoria or phytopthora. It's almost like a severe angular leaf spot but it came on this plant a lot faster than angular leaf spot hits my cukes.

Got an e-mail w/photos sent to my extension guy but was just wondering if anyone has seen this before.

[b54red]

I think what you have there is the result of a very tiny foliage leaf worm that shows up this time of the year. They usually hit tomatoes first but will eat anything in the garden. I have already had to spray my tomatoes with Sevin to stop them. I have also noticed they have chewed on the underside of some of my bean, cucumber and squash leaves but for some reason the last two or three days I haven't seen any worms so something is eating them. They are usually worse during rainy times and can be very hard to stop because for some reason BT doesn't work well on them. The only thing I have found that stops them for sure and quickly is Sevin.

The worms are so small when they first appear that they are almost invisible to the naked eye. Look for tell tale signs of transparent spots or areas on the leaves. Don't let the small size of these buggers fool you because they can totally defoliate a plant. I once was out of town for a few days and before I left I saw a few transparent looking spots on a large bell pepper plant and when I returned the leaves looked like lace and the only thing they hadn't eaten was the peppers but I'm sure they would have gotten to them next. There were thousands of them on the plant and they were over a half inch long at that point. I don't really know how large they will get because I have always sprayed with Sevn before they can do too much damage.

I suggest you look closely at your tomato leaves and see if they have started on them yet.

Bill

I’m finding those tiny worms on some of my tomatoes the last few days. It didn’t take long for them to grow to the point where I can see them easily and they did some damage. Those clear eaten out spots were exactly the same. Since the humidity is still relatively low I blasted the undersides of the leaves with water this evening. For whatever weird reason they love the KARMA plants a lot. Matsu Express right next door not touched, lol.

[brooksville]

I had success killing them with spinosad.

[brownrexx]

I have heard of southern Army worms defoliating tomato plants and Spinosad or bt kurstaki (Thuricide) should work on them.

[GoDawgs]

I had southern army worms try to defoliate my one eggplant last year. The extension agent had an entomologist at UGA identify them. She said that bT will work on them until they are 1/2" long. After that it doesn't work as well.

I used the bT and then handpicked every one of them that hadn't shriveled up overnight. A couple days of repeated inspections and handpicking the survivors that missed the cull fixed the problem.

[brownrexx]

I also heard that you had to get the larvae at a young age for the bt to work.

I bought a mugo pine shrub at a big box store a few years ago and one day I saw that it was almost defoliated and these worms were all over it. I identified them as Southern Army worms which we do not have in our area but there were LOTS of them. I heard that they got their name because they quickly become like an army in numbers. My shrub must have come complete with armyworm eggs when I bought it. I have never seen them since.

I forget what I used to eliminate them but it was not a food crop so I am not as fussy.