They're called "white flies". They have driven me crazy too. I use "yellow sticky traps" for tiny flies which I don't know the name of + they work great, it's the same idea as fly paper. This is where I buy them + it's advertised as also being for whiteflies.

http://www.planetnatural.com/site/xdpy/sgc/Natural%20Pest%20Control/Home%20Pest%20Control

sticky traps are technically traps for insect ID ... they will not solce your problem ... period ....

most likely you have eggs in your soil .. and you need to figure out how to get rid of them ... getting rid of adults alone will NEVER work

if its a food plant ... you have to figure out how to do it ...

if its an ornamental plant.. i suggest a systemic soil drench to kill the eggs.. and eventually the adults

ken

Sticky traps do two things, catch the adults so you can identify them (insect ID) and trap the adults so they cannot get back to the plant to lay more eggs, so they are also a control. The eggs the adults lay hatch into larva because the soil, where they are, has the right conditions or moisture and warmth and the simplest, easiest means of control is to let the plants dry out between watering. An easy method to determine if your plant needs water is to insert your index finger in the soil to the first knuckle and if the soil feels dry there then water.
One simple means of controlling the larva is to put Bacillus thuringiensis - Isrealanis, BTI, or mosquitoe dunks on the soil. Nothing you can buy is going to kill the eggs short of cooking the soil in your oven.

sterilizing the soil .... what a great idea.. see the link below ... lol ... one of my hobby horses ...

any plant that goes outside for summer ... should be treated outdoors in late fall ... either by repotting into sterile soil .. or with a drench of the soil ...

as they say ... an oz. of prevention is worth a pound of cure ...

when you bring a new plant home.. they should also be isolated .. and treated .. prior to introduction to the collection ...

ken

Here is a link that might be useful: oven

Let's not confuse gnats (black) and white fly. BTi as a soil drench is effective (very effective) for gnat larvae and will stop their breeding cycle and end the infestation.

White fly, which seems to be what the poster is describing, do not lay their eggs in soil but on leaf undersides and require a different treatment - in fact, all whitefly life stages are commonly found on the lower surfaces of leaves.

hence the suggestion to use a systemic chemical .... water it into the soil .. and plant sucks it up .. and the plant becomes toxic to all kinds of unfriendlies ...

ken

I guess my fear with systemics is using the wrong thing and doing more damage than nothing at all by killing the plant. I guess the bugs are killing it anyway, so I might as well give it a shot. Any idea of specifics on systemics that are generally safe on most plants? I'd like to try something that can be used on any of my outdoor-indoor plants without remixing for each since I have a knack for killing plants as it is...lol....

You should be more concerned with what systemic chemical is safe for YOU and the rest of your household (not just the plant). There are very few that are recommended for indoor use....because they are very toxic. The product will remain in the confines of the container for a long time, giving off fumes 24/7. They act differently when used in the soil, outside.

Why not tell us what kind of plants you're struggling with? Some tend to be horrible whitefly magnets, and others are just plain ornery!

There are other (much safer) effective products to use on whitefly, but without knowing what the plants are, I'd rather hold off on any suggestions.

hence the reason that i usually recommend application and treatment of the plants in fall ... while you can do it outside... before bringing the plants in for winter .....

apply all chemicals according to instruction .. and in fear of your own safety ... of course ....

ken

rhizo_1,
I've struggled off an on with whiteflies on tropical hibiscus. Do you have any suggestions for that? Thanks.

I don't have any suggestion for the control of whitefly on hibiscus, sorry. I live in and garden in a chemical free home and yard. My solution for tropical hibiscus, which are VERY susceptible to whitefly infestations, would be to put it on the curb. And then never invite one to my home again.

Not the answer most people want to hear, lol!

The link below will list several ways to control Whitefly.

Here is a link that might be useful: Whitefly control

Thank you for the link, kimmsr. Put my hibiscus on the curb? No way, rhizo1. These are my babies and I've even become a small-scale (pardon the pun, get it?...whitefly, scale...lol) hybridizer.

Good for you! Be sure to come back and let everyone know what methods have been successful for you. Whitefly are a REALLLLLL challenge to get rid of!