Hi all, I'm getting way too much leaf miner damage and need to try and suppress it if I can.
Anybody have any links to more info on the flies that cause the damage. What controlls should I look at?
Charlie, since leaf miners are in the interior of the leaf topical preps don't work well, and you certainly don't want to use a systemic on edibles.
Have you looked at Problem Solver #2 here where there are so many links given to various places?
If not and if for some reason you don't want to, if I were to give you links I'd go to Google and enter..leafminers tomatoes....and all sorts of links come up, and you can do that as well.
Most folks try to control the damage by removing affected leaves, which is what most places recommend.
I usually just remove the affected leaves; sounds like Spinosad might be another approach.
Here is a link that might be useful: pest mgt -- leafminers
Hi Carolyn, Suze and the group.
"Have you looked at Problem Solver #2 here where there are so many links given to various places?"
I'm sorry but I don't know what that is or where to find it.
I just tried the Google search and did find lots of good info. One of the best so far is listed below in the link.
From what I have read so far it looks like there are more then one type of fly that causes the leaf miner damage. Yellow sticky cards can be used to trap the adults. I hope I can get the yellow cards locally but I also found one online source:
I will try using the cards to trap some of the adults so I can ID them and then I want to try and use:
---cut from link below---
Parasitic wasps (parasitoids) of the families Braconidae, Eulophidae, and Pteromalidae are important in natural control, and in the absence of insecticides usually keep this insect at low levels of abundance. At least 14 parasitoid species are known from Florida alone.
I hope I can get a handle on this, for now I think I will start cutting off the infected leafs and then drop them into water with bleach to keep any more from hatching.
Here is a link that might be useful: Web page with lots of info on leaf miners
I would also suggest reading the link to the Univ of California site I provided -- they mention the parasitic wasps as well as Spinosad. And there are also a couple of other methods suggested towards the bottom of the page.
I'll post in the link to the problem solver thread below:
Here is a link that might be useful: problem solver thread
Hi Suze and the group, yes I read the link you provided. It was also good with lots of info.
Thanks for the link to the Problem solver thread.
I also posted a message on the IPM forum asking for ways to attract the parasitic wasps and got a reply that suggested some flowers can help attract the wasps, marigolds are one of the flowers and I was getting ready to plant my fall bed with golden guardian marigolds from Park Seeds. So I will go ahead with the marigolds and see if it helps atttact the wasps. It should also be interesting seeing if the guardian can help reduce the root knot nematodes in this garden. That was why I was going to plant the marigold. These marigolds are suppose to be very effective on RKN.
Sure hope it works, DC
Hi DC, regarding your comment about marigolds for RKN:
Be sure you get the "nematocidal" variety of marigold to till into the soil. See link below.
I also learned from some agricultural experts at the University of Hawaii that planting sesame cover crops can help control nematodes, so I am going to try that this year. Also recommended for both nematocidal effects and attracting beneficial predatory insects were daikon, mustard, rape/canola, & cowpea.
As for leafminers, they are really out of control here, even though I have planted whatever I could to attract predatory beneficials.
I have not found anything effective and organic (although I have not yet tried Spinosad) other than covering with very fine nylon tulle to keep the flies from laying their eggs on the leaves. It may not be practical to cover big tomato plants, and I don't bother with the older plants, but young seedlings can die if leafminers hit all the leaves, so it helps to keep them under nylon tulle until they get bigger and stronger.
Here is a link that might be useful: Nematocidal marigold
Pinch off every leaf miner damaged leaf, even if you have to completely denude the tomato plant. If there are any blossoms, consider pinching them off too, since the plant needs leaves (chlorophyll + sunlight) to feed fruit.
Spray thoroughly on tops AND bottoms of leaves with pyrethrin-containing organic pesticide to prevent new infestation and possibly kill eggs on bottoms of leaves.
According to that website:
Originally posted by University of California IPM Website:
The dominant species of Liriomyza leafminers in California is in flux. All species, however, have high resistance to organophosphates, carbamates, and pyrethroids. If these types of insecticides are used, leafminer populations will increase. Treatment recommendations currently involve the rotation of abamectin and cyromazine. Some species are also controlled to a certain degree by spinosad.
That has me concerned that my Neem II (Neem Oil + Pyrethrin) won't do the trick.
I haven't had to pick off a leaf miner damaged leaf in a few days. However now I have some chewing going on. A gardener's work is never done...