Adult silverleaf whitefly closeup Image courtesy CSIRO
When they are on a leaf, they look like a very small white housefly.
They’ll be in masses.
The eggs look like bumps on a leaf in circular patterns
Mature fly – approx. 1/8 inch long.
Whitefly are an increasing problem in gardens as commercial growers create insecticide-resistant strains of this insect.
So what can a homeowner do?
Coat a yellow plastic card with a non-drying glue such as Tanglefoot (Amazon link) This will attract flying insects such as whitefly and aphids and once they land, they can’t take off again. Yes, the cards get very gross. 🙂 You can see all the recently caught Whiteflies on the card and some dead bodies as well. The darker bodies are likely aphids (who are also attracted to the yellow cards)
Tip – if you have a severe whitefly infestation, set up the cards and then go to nearby plants and shake them vigorously. The whitefly will fly away and head for the cards. Once you see this happen, you’ll start to believe it works. 🙂
I do remember research from my nursery days claiming a 90% reduction in whitefly and aphids in a greenhouse within a few days.
In the garden, they’re very effective at attracting all manner of insects ( yellow is critical – other colors don’t work)
Soap sprays work well for home greenhouse control but the easiest way for home gardeners is the yellow tags with Tanglefoot.
This is a commercial page about Whiteflies from Florida. It’s very good from that non-organic point of view and it does deal with the issue of resistance to sprays (note the insect may become resistant to soap at some point if that’s all you use.)