Re: Pyrethrum safety on Droseras

Adrian Arnold (arnold@bigb.win-uk.net)
Mon, 12 Feb 1996 23:47:15

I have also tried this treatment (aka fly spray!), although not with
this product, and had no problems. I suspect that it's the
propellants etc. in with the chemical that cause the problem
particularly if you sprayed the plants until they looked visibly
wet. If there is a next time, try just waving the aerosol in the
general vicinity and the results may not be quite as
catastrophic:-)

>Hello Everyone,
>
>> Anyway I recognised pyretheum as being a "natural" insecticide - so
>> far I've
>only sprayed it on one pitcher >(with a nice family of green splodges
>("kids") & aphids). Have people tried pyretheum? Is it safe on
>drosera >and sarracenia?
>
>Well actually I have tried Pyrethrum - in the form of 'Keri Spray'.
>The spray can also had some other ingredients in so this might have
>affected what happened next, but it definitely contained Pyrethrum. I
>sprayed it on some Drosera Capensis seedlings (I wasn't prepared to
>risk my Cuneifolia) and within 3 hours they all died. Funny, the bugs
>survived :-() I would think, however, that maybe tougher plants like
>Sarrs might be OK but I wouldn't like to place bets. The things I have
>trouble with are thousands of little bugs which I like to call "Zebra
>Bugs" because they are about 0.5mm wide by 1.5mm long and they are grey
>and white striped.

I get these too, and have always assumed them to be a sort of
spring-tail as mine are always bouncing about:-) I think it's the
little clear worms that pupate into the small black flies but I'm
no entomologist (but I was a pesticide application specialist in my
last incarnation:-)). Either way, a good whiff of insecticide clears
them for a while if necessary but my Pings do a good job too.

They seem to emerge into tiny
>black flies (I don't actually think they are blackflies) which go
>everywhere. But my aquatic Utrics enjoy them (its a long story). But,
>to totally contradict myself and void everything I have said (it's my
>other hobby), I have used FISONS "Nature's Friends" pump-action spray
>sold in some garden centres which I have sprayed on all of my CP's
>(except Neps) until it drips off their leaves and this has done them no
>harm whatsoever (the insects wouldn't agree: they're whole population
>was wiped out).

Probably because this is water based. Most pressurised cans have
various solvents instead. It's rather wasteful to spray to run-off
though - save money (and cut-down on the environmental polution)
by giving half as much (or less?).

>
>
>The moral? I do not advise using CFC type spray - i.e. the stuff
>which comes in pressurised cans as When ever I have used this type of
>Fungicide/Insecticide before it has killed my Droseras.
>
>I hope this helps,
>
>Toby Marsden
>
>
>