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katietoo

What's Eating The Petunias?

KatieToo
10 years ago

Attached is a photo of one of three containers in the same bed that are affected by whatever this is. It seems to eat only the petunias, leaving the geraniums and the dusty miller in the containers, plus everything on the ground alone. Some of the holes are small like 1/8" sometimes it eats the entire blossom but not the "ribs" of the blossom if you will, just the draping part. There is a rhody arching partly over the bed and some of the containers which has a few affected leaves, but again, no bug I can find. Last week I found one striped caterpillar that looked like what we once called tent caterpillars, but none before or since then. Whatever it is leaves tiny black droppings. I have examined the affected plants in the early morning and at night and during the day both the top and bottom of the leaves, and the stems, and found nothing.
I am in Western Massachusetts. Any ideas on what this is and what to do about it? First it was hosta blight, now this. : (

Comments (8)

  • jean001a
    10 years ago

    A very early stage of the tobacco bud worm, which also goes by the names petunia budworm and geranium budworm.

    It's a caterpillar. Hole is small because the caterpillar is very young.

  • rhizo_1 (North AL) zone 7
    10 years ago

    Caterpillars leave little droppings that are green when smeared with your finger. But I can't count how many times that someone has posted about black frass all over the petunias only to find out that it was a spill of petunia seeds.

    Which do you think those little black things are.....caterpillar frass or petunia seeds?

  • KatieToo
    Original Author
    10 years ago

    Thanks for the replies!
    I'm pretty sure it's bug frass (although they don't smear, I just tried) because:
    1) The specks appear mostly on and below the affected blossoms.
    2) I pinch off the star underneath the faded bloom too, so I don't think the petunias go to seed.
    3) Petunia seeds are tiny and fine like ground pepper, except consistently black, right? These specks are mixed sizes, some larger than a sesame seed, except a tapered tube shape.
    I looked up the budworms, this is quite sad, one of the petunias is an incredible black with yellow stripes that I have never seen anywhere else.

  • KatieToo
    Original Author
    10 years ago

    Update: I spent 30 minutes at sunset looking at the three containers for critters. Leaves, stems, blossoms, crown, I mean I checked them out! I can't get to the crown of one because it is too dense, of course that's the Phantom! I found not one caterpillar, but the Phantom had a dozen or so of the insects pictured (through the bottom of a Mason jar). They are benign, yes?
    Now what? I was going to try to pick off the caterpillars and I read that they are most active at dusk, but where are they?

  • rhizo_1 (North AL) zone 7
    10 years ago

    Crickets eat plants, though not so much (in most locations) that they are considered a major pest, but capable of doing damage to a basket of petunias.

  • IanW Zone 5 Ont. Can.
    10 years ago

    Earwigs are another critter that loves to munch on flower blossoms, such as roses dalhias, petunias etc.....they feed at night and hide during the day, so you won't find them eating your flowers when you go looking in the daylight....

  • JR4094
    10 years ago

    We moved to another state last year and I too had my first experience with bud worms. When I saw the black specks I just thought it was tiny bits from the asphalt shingles of the newly built garden shed we had the petunia window box attached to. After reading about the symptoms that all pointed to bud worms I actually found a couple of the critters in the evening. I found a product by Ortho that listed it would take care of bud worms and it did. I was wanting to know if there were any DIY treatments or anything I can put into the soil before planting to help avoid these this year.

  • Kimmsr
    10 years ago

    The first step is to be sure the soil these plants are growing in is a good healthy soil so the plants can grow up strong and healthy and be better able to ward off insect pests. Then be sure that the environment is one that many insects, benefiicials and predators, will find comfortable so they hang around, which means not spraying broad spectrum poisons, such as Carbaryl, or pyrethins, pyrethroids, etc., around.
    Bacillus thuringiensis - Kurstaki is a relatively safe method of control if applied while the target insect is still quite small.