Die, Aphids, DIE!!

[PhillyGardener]

As the subject line suggests, I'm looking to annihilate an aphid infestation. I first noticed aphids on my (now) ~5 week old tomato, cucumber, and zucchini seedlings maybe 10 days ago. Green, black, red, winged, wingless--all kinds. I immediately started squishing them twice a day and sprayed the seedlings with a diluted soap solution (1 tsp Murphy's Oil Soap / 1 Qt water). Well, I didn't know to wash the soap off (oops) and burned the leaves. They've mostly recovered.

I've had moderate success keeping the aphid population in check through daily inspection and squishing. However, I failed to squish yesterday, and by this afternoon they had exploded. There are TONS of green winged ones as well as very tiny black winged ones. When I picked up one of my seedling trays to move it in tonight, I came away with aphids all over my shirt and head. Ack!!

Should I try another round of soap? I have Neem oil now, too. Is that better, or does it matter? I don't want to burn leaves again...

I started way too many seedlings and can definitely cull a lot of them if needed. I was hoping to give some of them to a local community garden that is just starting up, but I don't want to pass my aphid problem along to them. Should I just treat the ones I plan to keep and cull the rest?

Thanks in advance!

[applestar]

The ones that fall off the plants immediately walk their way back up. Try spraying the soil and trays with the soap solution, then going around squishing with soapy hands and/or knocking the aphids off with a soft bristle paint brush into the soapy bubbles, then finish with spraying with water to rinse off the leaves. This routine could take the place of watering.

Are they all in trays? I hold individual containers sideways and brush the aphids off into soapy water. Soft watercolor brush really helps to get into tender new leaves.

If they are solidly in trays and won't come out, I've seen videos of commercial growers holding the trays upside down and DIPPING the seedlings.

Take steps to keep ants away from the seedlings.

Oh, one more thing -- find some spiders and put them among the seedlings. Walking/hunting spiders are more effective than ones that sit in a web.

ETA -- I had another idea. You must be setting them out to harden off by now, right? When you do, surround them with flowers that attract beneficial insects like Sweet Alyssum (I think they would be selling them in full bloom by now in 6-packs, etc.).

Today, I was going to check one of my tomatoes already planted in the ground which had been stressed by the frosty nights spent under the tub and was attacked by aphids. Last time I looked, it had lost much of its dark green color and was infested by dark green aphids that had sucked the green out of it. But I'd noticed it was greening back up nicely.

When I peered in close, I realized there were hoverflies walking around on the leaves. I pulled back my hands that I had ready to turn over leaves and squish and left the Garden Patrol to their task.

[PhillyGardener]

I forgot to mention that I ordered 1,500 ladybugs from March Biological last week and released them into the garden at night. More than half poured of the box dead, which was disappointing and kind of depressing. I've since seen a few crawling around. I hope they stick around and lay eggs, but clearly they're not enough to keep the aphids in check. I haven't seen any ladybug eggs or young yet.

I do have some flowers around: lots of sedum (in bloom now), 2 marigolds, some yarrow (about to bloom), black-eyed susans (won't be in bloom for a bit), and a bit of clematis. I have a tiny yard though, so I don't have room for much more without sacrificing precious veggie-planting square footage!

Applestar, yes, they've actually been hardened off for ~2 weeks and waiting for someone (ahem) to plant them up from their too-small cups. I am seriously considering tossing everything but a few tomatoes since I have more than enough plants and can still start cukes and zukes from seed. Of course, then I worry that the aphids will attack the remaining plants. I guess I don't have anything to lose. I'll try the soap spray this afternoon and hope it works! Thanks!

[Dillbert]

get some Safers Insecticidal Soap - it doesn't burn plants, and you don't have to wash it off.

soap is not necessarily "soap" - and "detergents" are most definitely not "soap" - various additives / components used in "soaps" not intended for application to plants can have minor to fatal consequences for the plants.

and because it is not uncommon that manufacturers change up the precise formulation, if one used Brand X last year with no problem is no guarantee that it'll work this year.

[PhillyGardener]

Thanks, Dillbert. I used Murphy Oil Soap, which I heard many people have used with success, but even a diluted version of the recipes I found online seemed to cause leaf burn. I hate to spray anything that could kill beneficial insects, but so far I haven't seen many of those, anyway. Maybe I'll give it a try.

[Duets]

I sure hope the aphid problem gets under control for you.

I too purchased 1,500 lady bugs from my local nursery here, they were all alive except for only a few. Maybe try your local nursery for future lady bugs, just an idea. We have Star Nursery, they are a great nursery for the locals here.

[applestar]

The other day, I finally got around to cleaning up the mailbox area.
We have a honey locust tree there that always gets aphids. Years ago, my MIL cut one growing above her carport down because she said her car got all sticky from the honeydew. But with mine, every spring, I watch the backyard regulars -- goldfinches and house finches -- as well as ruby crowned kinglets that only appear at this time of the year hopping among the branches scooping up the aphids.

So I wasn't surprised when I found ladybugs all over the weeds under the tree. I called for a helper, and my DD and I gathered up about twenty of them to release in and under the cherry trees which always get hit hard by the black aphids. Once the area was clear of visible ladybugs, I was able to begin weeding, but I still found ladybug pupa one some leaves and more ladybugs.

My DD was so intrigued that she kept some in a jar fitted with a cloth lid and she's feeding them every day by picking an aphid infested leaf from a volunteer cherry sapling that is growing next to the front door. First time she was doing it, she was poking at the leaf with a stick. When I asked her why, she explained that there were ants shepherding the flock of aphids so she was flicking them away so they won't get in the jar and hurt her ladybugs.

Yesterday I noticed that there was an empty pupa in her jar, and when she counted, there was an extra lady bug crawling around. She observed that the new one was smaller and it's wings we're less clearly marked.

[PhillyGardener]

Applestar, that's great! I found a pepper plant at the farmer's market yesterday that had a ladybug clinging to it, so that's the one I chose

Unfortunately, the aphids are still around. Some plants have fewer, others (the ones that taste better, I assume) have more. I still wouldn't call it an out and out infestation, but it's not good.

On Friday afternoon, I sprayed everything with Neem oil (1tsp diluted in a 25oz bottle). A few hours later I went out and checked and there were still plenty of live aphids crawling around like nothing happened. Argh! Is Neem oil a kill-on-contact sort of thing, or is it meant to kill them as they feed on the plants?

Oh, and I also noticed some large red ants have started hanging in the garden bed. There have always been red ants around that area, so I don't think it's just because of the aphids, but I'm nervous!

My good friend is a master gardener (she does flowers though, not veggies) and said aphids are mostly cool-weather pests and should diminish in the heat. I hope this is true...

[cynthia_h]

On Friday afternoon, I sprayed everything with Neem oil (1tsp diluted in a 25oz bottle). A few hours later I went out and checked and there were still plenty of live aphids crawling around like nothing happened. Argh! Is Neem oil a kill-on-contact sort of thing, or is it meant to kill them as they feed on the plants?

Neem works on contact with the insects. It's not a systemic, if that was what you were asking. Systemics are notorious for killing both harmful *and* beneficial insects--pollinators and destroyers--and some have been implicated as co-factors in Colony Collapse Disorder.

Cynthia H.
Sunset Zone 17, USDA Zone 9

[rainbowgardener]

Sorry, cynthia, but that's not what the Neem oil people say.

Neem oil does not kill on contact. It has to be ingested by leaf eaters/ suckers. That's why it doesn't harm beneficials. Then it works inside the insect to block their processes.

Here is from the Neem Oil website:

Neem oil does work, but the way it works is different from other insecticides. Neem is not an instant, knock down, kill everything pesticide....Neem oil has many complex active ingredients. Rather than being simple poisons, those ingredients are similar to the hormones that insects produce. Insects take up the neem oil ingredients just like natural hormones.

Neem enters the system and blocks the real hormones from working properly. Insects "forget" to eat, to mate, or they stop laying eggs. Some forget that they can fly. If eggs are produced they don't hatch, or the larvae don't moult.

Obviously insects that are too confused to eat or breed will not survive. The population eventually plummets, and they disappear. The cycle is broken....

But this is not something that happens over night. People spray neem oil as insecticide, and expect everything to die instantly, because that's what they are used to from chemical poisons. When that does not happen they conclude neem insecticide does not work.

It does work! Give it time to work. It's a much smarter way to deal with insect pests than to just kill everything.

http://www.discoverneem.com/neem-oil-insecticide.html

[PhillyGardener]

I definitely don't want to use a systemic insecticide. I just wasn't sure if Neem killed on contact or if it took time to work. Since it does take time, I'll wait 7-10 days as recommended on the bottle to do another treatment. The good news is that there's no leaf burn this time! I think I'll stay away from soap spray and stick to Neem. Thanks, all!

[mattie g]

I've got aphids on my tomatoes, so I sprayed with Neem oil a few days ago. I was tooling around the garden yesterday and still saw mature aphids and eggs, though fewer in number than a few days ago. Hopefully the numbers continue to go down over the next week.

I'd love to put ladybugs out back, but I can't find them in any of the nurseries that are relatively close by. Oh well...

[rainbowgardener]

Plant yarrow, tansy, dill, fennel, coriander/ cilantro, butterfly weed in your garden and be sure not to kill off all your aphids. Ladybugs will come!

[PhillyGardener]

Plant yarrow, tansy, dill, fennel, coriander/ cilantro, butterfly weed in your garden and be sure not to kill off all your aphids. Ladybugs will come!

Oh, I couldn't kill them all off if I tried!! My cilantro now has aphids and red spider mites (ugh), I have yarrow planted just outside the raised bed, and dill within it. I also planted nasturtiums on the border, hoping to draw a few aphids away, but they have completely ignored it in favor of the tender new growth on my veggie plants.

It rained buckets this week, so I treated with Neem oil again. I have noticed a small difference in the number of aphids this morning. I can still easily spot them on most plants, but when I walk through the garden I don't come away with a dozen of them clinging to me, just a few. I consider this progress.

The only plants that really seem to be suffering are the tomatoes--I'm thinking about pulling up my Parks Whopper, which didn't look terribly healthy even before the aphids took over. The cucumbers are doing beautifully despite the aphids and have even produced a few baby fruit! My 8 pepper plants were drooping last night and this morning, but I think that's probably from the 2" of rain we received over the last few days.

[rainbowgardener]

The simplest thing for me with aphids is just to squish them. If they really are aphids (I'm a bit confused about them ending up on you, I've not had that experience), they just sit there and let you squish them. I have a couple plants that get covered with aphids every spring. I go over them with a kleenex and squish them and that seems to take care of it; they don't come back until the next spring. I think 100's of dead aphid bodies may be a deterrent to new aphids coming...