Vegetable garden pest questions.

April 8, 2006 4:11 PM

Garden pest questions and a couple insect identification requests for this bug and this bug.

I saw this bright orange and black bug yesterday (here is a blurry closeup) on a leaf on my tomato plant. I only watched it for five minutes as I watered - it didn't seem to hop or move quickly, but actually rather slowly, almost as if it didn't seem scared of me, yet went to hide under a leaf. Is it a pest, or is it beneficial.. or neutral?

A few weeks ago we saw the red wasp-like bug in the above link indoors on our window screen and I am just wondering what it was! That's unrelated to the vegetable garden.

Otherwise, should I be concerned about ants in my vegetable garden? Do they eat anything that I would want to eat (i.e tomato, spinach)? I've noticed some on spinach leaves, but otherwise they mostly like the tomatillo flowers. I am a little concerned about carpenter ants seeing as how I have raised beds made with untreated lumber ("IP wood," whatever that is). Should I be? Do ants aerate the soil? Seems a few have decided to make a home near the spinach (notice long trails consistently in a certain spot). Fire ants are the mainstay here, though I've seen at least one very large red and black ant (presumably a carpenter ant), many tiny black ants (those are the ones I've seen on the spinach leaves especially) and crazy ants. There really are a lot of them. Does anyone have any experience with this?

...Or with flea beetles, for that matter, and how best to control them? Those are a known problem, though a combination of garlic-cayenne spray, insecticidal soap & pyrethrin has seemed to keep them mostly away.

I am in Central Fl., Zone 9b. I am new at this (one month) and the lumber is new (if that matters). Any help or advice is appreciated!

posted by mojabunni to home & garden (9 comments total)

My boyfriend who works for Scotts offered up this, but he admits that the legs are way too long. Anyone else?
posted by Juliet Banana at 4:44 PM on April 8, 2006

I believe Bug #1 is an assassin bug. It's good.
posted by climalene at 5:37 PM on April 8, 2006

I agree with climalene's ID of Bug #1 - assassin bug and that's good. Bug #2 isn't familiar.

...one very large red and black ant (presumably a carpenter ant)...

Could that be a Velvet Ant? If so it'll do your garden or lumber no harm but can sting (they're actually wasps) so don't pick it up.

Ants in general won't be a direct problem in your garden. They do aerate soil and will eat many harmful insects. However, ants can "farm" aphids (aka plant lice or green flies) which can be a problem. The ants will maintain a "herd" of aphids, protecting them from enemies, then "milk" them for a sweet nectar, honeydew, that they exude. If you see a lot of ants it may be an indication that you have an aphid infestation (which is easy to control just by blasting them off with a hose or with insecticidal soap or "botanical" pesticides like pyrethrum). So the ants aren't themselves a problem, and in fact are benign or beneficial, but might indicate you have an aphid problem.

Carpenter ants shouldn't be a problem with new lumber or any small pieces of wood. They don't eat wood, they excavate in old or rotting wood it to make nests and therefore are only interested in large chunks of wood like tree stumps or timbers that are big enough for their colonies. I've had raised beds made from untreated lumber last ten years, although that's in the Northeast with a much shorter season for wood-chewing insects.

Fire ants are a problem because they're fire ants, not, I don't think, because they'll eat your tomatoes or spinach. I've no personal experience with them, though, as they haven't made it up here to New England (yet).
posted by TimeFactor at 8:35 PM on April 8, 2006

Thanks for the answers so far! I really appreciate it... The ant I saw that was very huge looked like this, which is described as a "Florida Carpenter Ant."

So far I have not seen a single thing in my garden that I would call an aphid, and I've searched (I have to manually water every day and I inspect/monitor every plant as I do). If I were to have that bad of a problem with aphids, wouldn't I have to have seen them by now at least once? Do they live in soil and only feast at night or something?

Before I planted the gardens, our lawn was (and still is) majorly infested with ants, predominantly fire ants. There's probably billions upon billions in our yard.. We'll have to deal with that soon, but I would assume that is the reason for the heavy ant infestation.
posted by mojabunni at 1:41 AM on April 9, 2006

I think bug #2 is some sort of clearwinged moth (Sesiidae).

Assassin bugs are very beneficial in the garden, but leave them be to do their thing: they do bite. Some people are allergic to their "venom," and a bite can sometimes--sometimes--have lingering side-effects.

Just a warning in case you, like me, occasionally let insects crawl around on your hand in order to get a closer look at them.
posted by halcyon_daze at 9:58 AM on April 9, 2006

Thanks, halcyon_daze... it is a clear-winged moth, as referenced by this image of the same bug, and by this one. That second image is on a page written in German, apparently. Babelfish was not very helpful in translating, as usual.. "Planning poison more beskytter more glassværmer (sommerfugl)" was all that came out. My curiosity is getting the better of me.. I'm really curious to know what species it is and about its behavior (is it poisonous, a threat in any way to humans or anything...). Kudos to anyone who can answer!
posted by mojabunni at 9:01 PM on April 9, 2006

Well mojabunni, this has really turned out to be interesting!

Bug #2 is in fact a scarlet-bodied wasp moth (native to Florida). The article you linked to referenced another article, written by a William Conner of Wake Forest University, entitled "A gift of poison: moths and safe sex."

Pertinent text: Safe sex for scarlet-bodied wasp moths means avoiding being eaten by predators while mating. So, the male moth, in order to protect his intended during courtship, covers her with a bridal veil of poison, says William Conner, professor of biology at Wake Forest University. The moths are immune to the toxin, but the poisonous cloud prevents predators from spoiling the wedding of the insect pair.

The scarlet-bodied wasp moth, native to Florida, is the only insect known to transfer a chemical defense in this way, says Conner. He discovered the moth's distinctive behavior while conducting research at the Archbold Biological Station near Lake Placid, Fla.

Your moth is not only strikingly beautiful, it's also not a pest , and has the added benefit of being rather unique and fascinating.

What a treat! Thanks for the opportunity!
posted by halcyon_daze at 2:45 PM on April 10, 2006

Ooh, thanks! It's called a Cosmosoma myrodora.
posted by mojabunni at 8:01 PM on April 10, 2006

Video of the "courtship ritual."
posted by halcyon_daze at 8:15 PM on April 10, 2006