Subject: white flies -- yuk!

From: [email-masked] (Susan Wilson/Branson School)
Date: 22 Jan 1996 21:01:27 GMT

HI,
	We have a greenhouse here at our school and we have a big problem 
with white flies.  Does anyone have a suggestion as to how we can deal 
with these pests?  We have been spraying with soapy water, but that is 
only a temporary cure.

							Thanks,
							Susan Wilson

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Susan Wilson			
Branson School
Box 128
Branson, Colorado   81027

[email-masked]

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From: [email-masked] (Willaim H. Reid)
Date: 23 Jan 1996 05:19:33 GMT

In article <[email-masked]>, [email-masked] (Susan
Wilson/Branson School) wrote:

><snip>
Susan -
We did good control by adding some dish washing liquid to the water.
Apparently the eggs and larvae are in the soil and the change in surface
tension caused by 
the soap does something disasterous for them. Also wipe the bottoms of the
leaves gently with the same. We also occasionally burnt a smudge of oak
leaves
in the greenhouse. (The floor was concrete so there was no exposed soil there.)

This was all "they say" info but it seemed to work in the warm and rather dry
greenhouse in El Paso. 
Bill Reid

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From: Gilles Guerin <[email-masked]>
Date: 24 Jan 1996 16:05:13 GMT

A good class of chemical to control white flies are pyrethenoids. Adults flies are 
very sensitive to it (by contact) but eggs and larvas aren't. You can use it in 
combination with yellow sticks to capture remaining adults. (Fumigations are of no 
use.) There is also a natural predator, a kind of wasp, which is currently in use in 
tomatoes commercial greenhouse agriculture. (sorry I can't remember its name). 
Pyrethrin is almost non phytotoxic and is not toxic to humans. To get rid of eggs you 
could use oily emulsions containing either pyrethrin or dimethoate (in this case 
phytotoxicity is very high).