At 2:15 PM +1200 00/7/17, Nick Wallingford wrote:
>> What is an environmentally acceptable chemical to destroy a
>> colony in the wall of a house?
>
>I have used as little as 2-3 tsp. of Derris Dust (Rotenone to the US
>readers?), a pesticide that is relatively non-toxic to *most* non-target
>life forms.  Generally, though, I'd use several tablespoons to be more
>certain...
>
>Use a small tube to blow the dust into the entrance of the colony and it is
>almost always effective.

        From the viewpoint of official toxicology, that is sound advice.
The natural insecticides from that African daisy _Pyrethrum_ , a class of
compounds called 'pyrethroids', have a good reputation.
(It should be added that synthetic insecticides based on the molecular
structure of the natural pyrethroids are not necessarily OK.   I for one am
suspicious of fluoxetine, the main ingredient of Apistan®, which has 3
fluorine atoms and one chlorine atom in its molecule.)

R

-
Robt Mann
consultant ecologist
P O Box 28878   Remuera, Auckland 1005, New Zealand
                (9) 524 2949