Agriculture Reference
In-Depth Information
begins to feed. Like many other mites, this blood meal is needed so she can begin laying
eggs.
Like the tracheal mites, her firstborn is a male, who then mates with his sisters, who
are produced next. One or two of these now-mated female mites, plus the mother, leave
the cell when the bee emerges. Varroa females by far prefer drone pupa to workers be-
cause of the longer time they are in the cell, allowing them to produce more young, but
workers and even queens are not immune.
Larvae that are attacked by varroa mites suffer all manner of problems. Varroa can
transmit viruses that will stunt and eventually kill the newly emerged bee. Parasitized
drones are shorter lived and less vigorous flyers than healthy ones. Workers, too, are
shorter lived and have reduced feeding capacity, flying ability, and general health.
When young, newly mated female mites emerge with the drone or worker on which
they had been feeding, they seek new cells to invade and repeat the process. The males
do not leave but die in the cell. No matter what treatment choice you make, when the
females are exposed, they are at the weak spot in their cycle. You must control varroa
mites or they will eventually kill the colony. Fortunately, several treatments are avail-
able, and monitoring mite populations and treating is a routine part of varroa mite man-
agement.
If you remove a larva from its cell that has a varroa mite already in it, this is what you
will see. Note the size and color of the varroa mite. They are easy to identify. Gener-
ally, when you remove the pupa from the cell, the mite will scurry away, and they can
move fast.
Monitoring Mite Populations
To win the varroa mite battle you first must know how many mites are in your colony.
Knowing that number will tell you if there are so many there that you need to take ac-
tion, or perhaps your avoidance techniques are paying off and you can relax.
You will encounter several techniques to use to sample your colonies for the pres-
ence and number of varroa mites. There is the ether roll, where you capture about 300
bees from a colony in a 1-quart (1 l) jar, cover and spray with automobile starting flu-
id (ether). This kills the bees. As they die they regurgitate the nectar in their stomachs.
This collects on the inside of the jar as you roll the jar of bees for several minutes. It
also kills any mites clinging to the bees. Many of these mites are caught in the sticky
