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Re: insect control

Well you're right Daryl if your neighbors are all spraying and you're 
not you will have a more difficult time if not impossible to control in 
a natural way.  I had a nasty white fly invasion in my backyard this 
year.  I've never seen  them like this.  I figure it was because we had 
such a mild winter that the population wasn't killed off by the cold.  
In any case my wife urged me to spray the little blighters.  I resisted 
mainly because I have a nice population of birds including several 
hummers and I didn't want to poison them.  Not to mention the bees and 
other beneficials.  I did cut way back the plant that seemed to be 
housing them and that was the Melianthus.  Problem now seems to under 
control and I never did spray.

I understand the city of San Diego destroyed many of their venerable 
Hibiscus trees because of a white fly problem.  I have come to 
understand that most people do not know how to use insecticides in the 
proper way.  I suspect that was the case of San Diego but I'm not sure.  
Rotation is the most important aspect but if the population is bad you 
have to spray every three days at least three times to kill off the 
succeeding generations.  If you don't do that you won't take care of the 

Biologicals to me aren't very useful in the greenhouse if you are going 
for near zero population.  First their temperature range makes them 
fragile.  Second, you have to have a population of bad guys otherwise 
your beneficials will starve to death.

Interesting piece on the vacuum method.  I wonder if PETA will become 
involved?  They certainly don't like it when they force feed geese to 
make froi gras.


Daryl wrote:

>You've raised a good point. You'll notice I used the words "resistant"
>instead of "immune" and "usually" rather than "always".  ;-)
>There are times when you can't let Ma Nature do it all, particularly, as you
>mentioned, if it's an imported pest with no natural controls. Sometimes,
>too, the beneficial insect population has been so knocked down by other
>folk's spraying, or because of weather, that some help is needed.
>Where intervention is needed, I try to use the least toxic method for the
>job. Many insects can be removed with a blast of water, or by smooshing
>them, or clipping off severely infested branches. Insecticidal soap sprays
>are useful for some soft-bodied insects such as Aphids. Ultra-fine hort oils
>such as Sunspray will do quite a fair job on White Fly (at least the two
>kinds that we get here) and on Spider Mites.
>When I used to work in a greenhouse, we also used Cinna-mite, and one year
>an IGR for the Poinsettias. The greenhouse owners tried to avoid harsh
>pesticides as much as possible, preferring to release predators and do spot
>spraying w/ water or hort oil. It's not always possible in that kind of
>un-natural environment, though. If nothing else, the high fertility levels,
>particularly Nitrogen, make the plants more attractive to insects, not to
>mention the inevitable crowding and the need to sell pest-free plants.
>I confess to using an IGR in my own greenhouse one year, when the White
>Flies were so bad that I couldn't inhale, and you couldn't walk through it
>without slipping on the insecticidal soap. It was my fault for not paying
>attention, though, and also for bringing in an infested plant that I felt
>sorry for. Never again!
>(I also should add that I still have my original bottles of both Sunspray
>and Insecticidal Soap after many years. Obviously, I don't use very much.)
>----- Original Message ----- 
>From: "David Franzman" <dfranzma@pacbell.net>
>To: "Garden" <gardenchat@hort.net>
>Sent: Sunday, October 05, 2003 2:39 PM
>Subject: [CHAT] insect control
>>Hey Daryl
>>I just read your letter about allowing mother nature to take care of the
>>insects in the garden.  I completely agree with you with this caveat:
>>Under your guidelines how should one control an insect invasion from a
>>foreign nation or area when that harmful bug has no natural controls?
>>There are many instances of this but the two that stand out here are the
>>Glassy Winged Sharpshooter (from the southeast) which damages vineyards
>>and more important for me and my business is the Giant Whitefly from
>>Mexico  which leaves a nasty white stringy goo on Hibs and other
>>plants.  Neither of these insects have a natural predator here so I was
>>wondering how your philosophy deals with this kind of menace.  (Again,
>>in my garden I practice what you describe.)
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