Thrips control

[liam1 at VIOLET.BERKELEY.EDU]

We too have had occasional problems with thrips, although aphids 
seem to be our major pest.  The compound Orthene (made by Ortho) 
works very well for both of these bugs.  It moves systemically within 
the plant and kills for a week or so after spraying.  Orthene is also 
called Acephate(O,S-Dimethyl acetyl-phosphoramidothioate).  The 
UC-Berkeley Dept. of Plant Pathology greenhouse hires a professional 
firm to come in and spray with very concentrated (50%?) Orthene, 
and it doesn't seem to bother the Arabidopsis very much.  I gather 
that non-professionals cannot buy Orthene in such concentrated 
formulations, which is why I mention this.  You can buy household 
sprays that are 0.25% Orthene, and that can help for treating small 
problems or individual plants that you are especially fond of, but it is 
pretty useless for heavy infestations.

There are problems with residual pesticide (it's a strong 
cholinesterase inhibitor) so the policy is not to spray in chambers but 
rather to move infested material to the spraying area.  I should 
stress that we really have used Orthene more for aphids (with 
excellent success).  However, Orthene seemed to work in our one 
experience with a small thrips infestation.  Hope this is of help.

-Andrew Bent