|My question is do whiteflies carry over to the next year in an outside garden? I was infested with them last year but I now know that the greenhouse the plants came out of was infested with them. This year I'm buying the plants from Burpee.|
|Yes, the eggs can overwinter and a new population will hatch when spring weather arrives. There are a number of biological controls that you can try to get rid of white flies. Depending on whether the infestation is inside a greenhouse, or out in the garden, there are several natural enemies that you can purchase to help control the white fly population.
A predacious wasp (Encarsia formosa) can be released inside greenhouses to control white flies. The wasps are available through: American Insectaries, Escondido, (619) 751-1436, Applied Bio-Control, (209) 874-1862, and Beneficial Insectary, (800) 477-3715.
Since you're dealing with an outdoor white fly problem, you might want to try releasing lacewings or minute pirate bugs, both available through the above suppliers.
Other control methods include yellow sticky traps - basically cardboard painted bright yellow and coated with mineral oil or petroleum jelly, and suspended near the tops of plants. Insecticidal soaps work well against white flies, too. Just be sure to spray both top and undersides of leaves. Insecticidal soaps can cause burning of leaves if applied during hot weather, so use caution.
Good luck in getting rid of those pesky pests!