If semen is collected and stored we need to have some
measure of the way it degrades with time or contamination.
Drones do not become properly sexually mature until they
are at least 14 days old and have had five good flying days. It is
thus recommended that drones not be used until they are 15 days old
or more if the weather has been uncertain.
There is a limit to the age that a drone is useful
(more here later)
Varroa treatment using Formic Acid renders the drones dry
and impotent. And many other chemicals that are used for varroa
treatment are under suspicion of causing drone infertility. There is
also the possibility that drones exposed to residual doses of these
chemicals may have defective or short lived sperm, even if they
produce semen.
It is therefore recommended that colonies intended to
provide drones for insemination should be treated the previous year
so that the reared drones are not affected by fluvalinate or other
residues.
Semen stored in the spermatheca of a queen appears to
remain valid and fertile for the life of the queen, certainly semen
taken from one year-old queens is no different in viability to semen
taken from 3-week old queens.
Semen can be stored for six to eight weeks at room
temperature, with a gradual reduction in viability. After 9 months
this viability is reduced to 50%. (half life? is 18 months 25%?)
Propidium iodide
will bind to DNA in dead sperm and will
glow red when illuminated with light in the visible spectrum from an
argon-ion laser. This avoids the harmful effects of UV exposure.
The SYBR-14 stain glows green when attached to live sperm.
(When I find out the precise method of staining I will add it here)
Revised (but incomplete)... 22 October 2001
