One of my houseplants has a load of small (1-1.5mm) thin, white bug things on the surface of the soil. Too small to photograph. Using a natural fatty acids bug killer makes them jump around for a little, then gets rid of them for a few days, but then they return with a vengeance. Any suggestions?

Have you done the "spray twice a week for several weeks" thing?

My understanding is that the insecticidal soap only kills adults. The eggs are still in the soil, hatching over the next few weeks.

RickCorey said:Have you done the "spray twice a week for several weeks" thing?

My understanding is that the insecticidal soap only kills adults. The eggs are still in the soil, hatching over the next few weeks.

Yep - been doing it for a couple of months.

Ouch.

These won't be solutions, but might reduce the annoyance: sticky yellow traps, and top-dressing the pots with something that sheds water and stays dry: coarse bark chunks or Perlite or very coarse grit.

It sounds like you need a harsher insecticide. If your approach is "anything but that!", you might consider re-potting the plants affected ... but that's a blind shot in the dark.

If they were fungus gnats, I might urge you to use a LESS organic fertilizer, if you do use compost or organics that might be decomposing in the pot and encouraging fungus. But I think the soap would have killed fungus gnats.

I hope you get some useful suggestions!

Are you watering with Insecticidal Soap or just spraying? I would use it in every watering.

I'm not averse to stronger stuff than the fatty acid stuff I've been using. Would just like rid of them without binning the plant as I've had it a long time now :-(

And I've just been spraying every 3 days or so.

Do they look like this?:

http://www.extension.umn.edu/g...

sooby said:Do they look like this?:

http://www.extension.umn.edu/g...

The little worm-like things in the top photo, yes, the bigger ones no - but maybe they don't get to develop that much?

The different sizes would be different ages. There's a video of springtails that might help with the ID (I haven't listened to the sound as DH is watching TV!) - this video is not for the squeamish:

https://m.youtube.com/watch?v=...

sooby said:The different sizes would be different ages. There's a video of springtails that might help with the ID (I haven't listened to the sound as DH is watching TV!) - this video is not for the squeamish:

https://m.youtube.com/watch?v=...

That looks like the little buggers. Not quite so densely populated as that though, but still if I leave it a few days get easily ~100 or more. Quick read says starve of water - but I rarely water this plant - often weeks between watering (obviously the spray gives moisture though) and has been to the point of leaves dropping off.

One good thing...I've finally found out what kind of plant it is - a Jade Plant - Crassula Ovata apparantly. I just know it as "Bob"...

Azamax is your answer. Gene

Poor soil quality is the source of the problem. However, replacing the soil is a drastic solution that will probably kill the plant as well as the critters. If you repotted your Crassula, then it is probably in a pot that is too large, in which case you can consider removing excess soil from around the outside of the original rootball, but leave the original rootball intact.

In any case, remove any soil from the surface that is not in immediate contact with the roots. The top layer of soil is where many of the larvae live. The excess top soil also keeps the soil in the root zone from drying out properly. Starving the larvae of moisture is the key to control. For that reason, I suggest you stop spraying and adding any liquid substances to the soil. Crassulas don't tolerate constantly moist soil, so it will benefit from your allowing it to dry out.

Thanks Will. Have moved it to a sunny place and left it alone for this week and that seems to be doing the trick. Any guesses as to whether leaving it like this will completely eradicate them or if I come to water it again some weeks down the line will I get the same problem coming back?

I don't think repotting a jade plant will kill it. You could rip it out of the pot and leave it lying someplace and it would root where ever you left it. Overwatering will and if its over-potted, the chances are great for overwatering. They don't need a lot of root space - a pot big enough to hold the plant up is big enough.

If you see bugs again, I would take it out of the pot, get rid of all the soil (wash the roots off) and repot in new soil.

Daisy