I agree, the problem isn´t how they are produced, rather how they are
created/used and especially how they are degraded.

What is commonly referred to synthetic miticides are pyrethroids that have
been chemically altered to make them more stable (and maybe patentable).
That is what synthetic (man-made) is referring to in this case how they
were created, not how they are produced.

What can´t be degraded accumulates, leading to sublethal or even lethal
effects over time. Constant sublethal dosing is also the perfect condition
for resistance development.

For hobbyists there are biotechnological methods published that work
reliably completely without using chemicals. They are just labor intensive.
See publications of Ralph Büchler or his talks (
https://www.youtube.com/watch?v=tuJlgzcQWAg)
If you have time, just a few hives and ideally chickens to feed the
sacrificial varroa infested bee brood to: perfect.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html