Sunscald or pests?

[aobrion]

This is my first year gardening in general, and certainly my first attempt at growing tomatoes. I started these indoors, and moved them to a bigger pot and outside a few days ago, I think it was last Wednesday? I did try hardening them off as I was told was necessary, by leaving them in the spot where I eventually moved them to for a few hours each day, starting off with only 2/3 hours, and moving up to all day. I just noticed these marks on the leaves yesterday, and but when I checked underneath the leaves, there's nothing there. Did I just not harden them enough, or do I have pests eating up my Tiny Tim's? Thank you so much in advance.

[applestar]

Top photo with your hand supporting it has SERIOUS leaf miner tracks. Squiggly lines so this is the fly maggot, not the moth caterpillar (there are two kinds -- I get the caterpillar kind on the tomatoes around here ... different kind badly affects aquilegia). They are hiding between the top and bottom surface layers of the leaf and impervious to soap, etc. contact spray. Clip off all infested leaves and discard (burn and destroy, tie off in bag and trash, etc ).

Haha if you zoom in on that photo, you can see the bumps at the end of the trails where the maggot is actually hiding.

With less severe infestations, you can squish them by pinching those bumps with your fingernails, without removing the leaf. I've tried using ticket punchers, too... that was a little too tedious, though there might be better designed punchers. You can also trim the leaves with scissors. But these are only reasonable action in the initial stages of infestation. After they get out of hand, you'll find yourself simply pulling off the infested leaves any way you can.

[aobrion]

Thank you very much, I just removed most of the infected leaves and squished a few others. I'll keep an eye on them over the next few days and keep my fingers crossed!

[Ninjakatz]

I also have these on my tomato plants. Best thing to do is to watch your plants everyday and cut or squish any maggots you see. Hope there was a way to battle them.

[Dirt]

As much as an organic gardener would hate to do this, you can use a dust or spray safely if the plants aren't flowering. If you want a more natural approach you can try soapy water spray, but I don't know that it'd get to the ones inside the leaves. Or, you can used neem oil. Here's a link to some info.

https://www.gardeningknowhow.com/plant- ... ontrol.htm

[applestar]

Sprays are ineffective once the miners are inside the leaves. The lethal poison has to be systemic (absorbed into the plant tissues and vascular system) to work. I don't believe those are organic.

Bt on the leaf surface may infect the moth type but is ineffective against the flies. Some kind of repellant spray might help -- garlic, rosemary, lavender oil.... perhaps neem oil would repel them too? I don't know how much of the neem oil they will ingest when the oil is on the surface.... Some claim neem CAKE worked into the soil will help.

The caterpillars and maggots emerge from the leaves when ready for the next phase and drop down in the soil to pupate. So if you have barrier mulch or thick mulch on the soil surface that block them, it should help. OR active in-ground Garden Patrol like ground spiders, beetles, centipedes, predatory nematodes, etc. could help interrupt their life cycle.

I have heard that the yellow sticky traps work well to catch the adult flies (...also helps with the whiteflies that carry yellow leaf curl tomato virus) -- I had the impression that the traps are meant to catch them BEFORE they lay eggs and begin the infestation.... But the traps are indiscriminate and will also snag beneficials, so you have to weigh your options.

[Dirt]

Neem Oil will penetrate and work, but it's slow. Best thing to do would be to get rid of them then spray Neem as maintenance.

[rainbowgardener]

Leaf miners, unless you get a serious infestation, are one of the most benign of garden pests. The amount of leaf tissue they consume doesn't matter to the plant.

Their life cycle is that the larva tunnels around inside the leaf (where it is not vulnerable to any sprays) eating leaf tissue from the inside. When it is ready it chews its way out of the leaf and drops down to the ground below. It burrows shallowly into the soil where it pupates. After a week or two, the adult emerges. So you can help prevent the next generation by having a weed barrier in place under affected plants, so the larva can't get to the soil.

Lambsquarters and velvetleaf are trap crops for them. If you have these growing near the things you want to protect, the leaf miners will attack them preferentially. Those big soft leaves of velvetleaf are a magnet for them:



I used to have some of this growing in my garden and almost never had leaf miners on anything else. You just have to keep pulling infected leaves off the velvet leaf.

Velvetleaf is non-native, but it is useful to pollinators and beneficial insects:

" The nectar and pollen of the flowers attract various kinds of bees, including bumblebees, long-horned bees (Melissodes spp.), leaf-cutting bees (Megachile spp.), and Halictid bees. Occasionally, small- to medium-sized butterflies visit the flowers for nectar, while Syrphid flies feed on the pollen (Robertson, 1929)." https://www.illinoiswildflowers.info/wee ... etleaf.htm

[rainbowgardener]

I reminded myself about this! I used to have velvetleaf volunteering at my old house. None here and I had pretty many leaf miners last year. So I went looking for where to get velvetleaf seed. Harder than you think; most of what is on-line about velvetleaf is how to get rid of it. But I did find an Etsy shop that had it.

Turns out those leaves are edible and used for fiber and have medicinal value. I didn't even know!

https://www.etsy.com/listing/167452505/ ... s-abutilon

[john gault]

I just leave the leaf miners alone, they really don't harm the plant.