Beetles on tomatoes, can't identify. A thousand black larvae on leaves, tomatoes and ground - Ask Extension
A black beetle that doesn't look like a striped cucumber beetle is leaving a huge amount of black larvae on tomato leaves, on the ground and even som...
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Beetles on tomatoes, can't identify. A thousand black larvae on leaves, tomatoes and ground #418853
Asked August 02, 2017, 7:06 PM EDT
A black beetle that doesn't look like a striped cucumber beetle is leaving a huge amount of black larvae on tomato leaves, on the ground and even some on some nearby zucchini leaves.. I washed them away this morning, and they are back again this evening. Is the beetle harmless? I can't find a photo identifying them online. It is .5 to almost .75 inch long (body and head). I remember seeing these a couple of times years ago outside of a garden setting and wondering at first if it was a firefly.
St. Mary's County Maryland
Expert Response
This is a type of blister beetle.
Here is a page about them:http://extension.umd.edu/hgic/blister-beetle-flowers
You can wear gloves and hand-pick them.
We wonder if the plentiful black pellets you are seeing are actually the droppings of the tomato hornworm, who can devour tomato leaves at quite a pace. They are hard to see as they blend in so well, and usually people notice them when they see the pellets first.
Take a look at the page at the link below, then hunt for them. If they have white rice-like appendages on their backs, leave them be as they are being parasitized by a beneficial insect and won't live long, as the beneficial's babies will hatch out soon to help control more of them. See here: http://extension.umd.edu/growit/insects/tobaccotomato-hornworm
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Here is a page about them:http://extension.umd.edu/hgic/blister-beetle-flowers
You can wear gloves and hand-pick them.
We wonder if the plentiful black pellets you are seeing are actually the droppings of the tomato hornworm, who can devour tomato leaves at quite a pace. They are hard to see as they blend in so well, and usually people notice them when they see the pellets first.
Take a look at the page at the link below, then hunt for them. If they have white rice-like appendages on their backs, leave them be as they are being parasitized by a beneficial insect and won't live long, as the beneficial's babies will hatch out soon to help control more of them. See here: http://extension.umd.edu/growit/insects/tobaccotomato-hornworm
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Thank you very much. The black larvae are from the beetle. I watched them place the larvae on some of the leaves. They place them in crooks of leaves, on tomato fruit, the ground and a couple larger squash leaves. Will they feed on tomatoes? Should I wash them away. There are too many to remove them by hand.
Blister beetles do feed on tomato foliage. You can try washing them away with a strong stray of water. The following publication from Virginia Tech also offers information on how to control them.
https://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/3104/3104-1543/3104-1543-PDF.pdf
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https://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/3104/3104-1543/3104-1543-PDF.pdf
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