For three years now we have had a white fly infestation. We have used Neem Oil, Insecticidal Soap and sticky yellow traps - all with only limited success. I need some other suggestions. We live along the Front Range of Colorado - relatively dry except when you make it a point to water. Help us solve this debilitating greenhouse pest. Thanks!

-- Steve Dananay (sdananay@hotmail.com), March 25, 2002

Answers

about the only other thing to do,, is let in lady bugs,, they eat the larva

-- Stan (sopal@net-pert.com), March 25, 2002.

Steve, I just recently bought a plant from our nearby hardware/nursery chain called Butterwort (Pinguicula). It was on their carnivorous plant display with Venus Flytraps, etc. I looked up the plant in my plant encyclopedia and read that this plant can be used for controlling aphids and whiteflies in greenhouses. Do an internet search on Butterwort or carnivorous plants and I'm sure you'll find a source to purchase it. It may take quite a few plants, but might be fun to try, anyway. Also, have you tried GardensAlive! ? They carry organic products and I know they have something for whiteflies. I think they might have a beneficial insect (besides ladybugs) that you can release inside your greenhouse. www.gardensalive.com Good luck!!

-- Bren (wayoutfarm@skybest.com), March 25, 2002.

You know, we did try Ladybugs - again with limited success. I am installing a swamp cooler this year to keep the greenhouse moist and cool. Perhaps the Ladybugs will flourish more in that environment. (But maybe the White Flies will too.) Thank you for your input!

-- Steve Dananay (sdananay@hotmail.com), March 25, 2002.

Finally, one I know the answer to! Here in San Diego the past few years we've had horrible whitefly infestations. Thanks to one of our local weatherman/organic gardener's (Loren Nancarrow on KGTV) we finally got them under control. The secret is the interval of treatment - treating every five days until they are erradicated. I pesonally did not have to use the yellow sticky traps though our problem was outside and not in a greenhouse.

Here is his excerpted advice from his website at www.thesandiegochannel.com/weather/lorensfieldnotes/archive.html

Whiteflies Loren's Field Notes

First, wash your plant very well with lots of water. This does two things. It knocks many white flies to the muddy ground below. Once drenched and muddy, they will not survive. The washing also chases away the many beneficial insects which will ultimately help us eradicate the whiteflies.

Secondly, rewash the plant, but this time use a hose end sprayer with a teaspoon of dish soap, and a tablespoon of canola oil in the sprayer and then fill with water. This will act as a non toxic insecticide which kills any fly it hits.

Lastly, hang a yellow plastic picnic plate (or commercial sticky trap) near the tree. Spray cooking oil on the plate to create a sticky surface. This will trap many more flies who are attracted to yellow.

Control is an ongoing job with whiteflies, so make sure to repeat the first two steps in 5 day intervals to kill any young that hatch.

-- Pamela (pcoomey@cox.net), March 25, 2002.