Nicotine sulfate is (I believe) derived commercially from tobacco, not
synthesized. I have always heard that you can transmit TMV (tobacco
mosaic virus) using nicotine as a pesticide. I don't know if this is
anecdote or data (the plural of anecdote is not data).

Many orchid growers won't even allow people to smoke in their
greenhouse, myself included. Again for fears of TMV transmission (or in
my case, because I can't stand cigarette smoke). If I see somebody
smoking in the greenhouse, I'll assume they are on fire and act
accordingly. I can use the TMV thing as an excuse... On the other
hand, I know many very good growers who smoke like chimneys, in the
greenhouse and out. They don't seem worried about TMV.

For my money, there are far less toxic compounds than nicotine that you
can use for your pesticide needs. Many of the chemical pesticides you
can buy off the shelves these days are almost completely non-toxic to
mammals (at the recommended doses, anyway), the toxic ones are just not
available anymore. Just because it is 'natural' does not make it safe.
Most of the most potent poisons known to man are natural (dart frog
toxin, ricin, and botulism toxin are three nasty ones). Nicotine is
right up there.

I'd dispose of the nicotine (safely, somehow) and stick with the bayer
spray (imidocloprid).

What concentration do you mix in?

I have never used the black flag nicotine. Bottle is 20 years old.

The tree & shrub I use 4 oz into 2 or 3 gal.which is not on the
container, but I worked out from this article:

http://www.njorchids.org/articles/Mealybug/Mealybug.htm

This stuff is toxic. keep it away from people and pets, which is not
spelled out on the container.

One container (32 oz) is about enough to treat a couple thousand
orchids for a couple years.



--
Rob's Rules: http://littlefrogfarm.com
1) There is always room for one more orchid
2) There is always room for two more orchids
2a) See rule 1
3) When one has insufficient credit to obtain more
orchids, obtain more credit