They are, as you suspected....white flies! Lol! Anyway, they are super annoying, and the easiest way to lower their numbers is regular hard sprays with water, and you can also use insecticidal soap on the undersides of the leaves to smother them. That's alot harder than you think because lantana are usually huge and it's really hard to get under the leaves. There are lots and lots of other methods, like Vaseline on the paper plate trick, releasing or attracting predators (hummingbirds and green lacewings), using pyrethrin sprays, vacuuming them up, and others. Do a search of Gardenweb typing in "whiteflies" and you will get tons of results.

Bayer makes a systemic insecticide/fertilizer combo that I started using last year and it works on a number of pests and whiteflies is one of them. I treated all my lantana except one with it to see if it would work. Only the one lantana had the white flies after two weeks. So if you don't mind using " Chemistry for Better Living" give it a try. I use the Rose systemic for everything , but I think they have a general one out now.

Is it this product?

http://ec1.images-amazon.com/images/I/311W7JBYW6L._SS500_.jpg

Thanks for replies. I got some insecticide soap from Lowes and sprayed the heck outta all/most of my plants. Seems like numbers went down. I want them DEAD!!! ALL OF THEM! LOL They ruin my nice yard. I probably will do this product or more soap next week again.

Eugene

try earth worm castings!!! the white flies don't like the way it makes the plant taste. plus, it's a great for your plants.