Mite Check

Summer is the time for mite checks.

The varroa destructor mite (quite a name!) is a tiny monster that infests beehives. It reproduces in the cells where young bees mature and emerges with them to do its dirty work. Male bees (drones) are its favorite hosts because they take 28 days to mature, as opposed to their sisters who take just 21 days.

Varroa mites are a problem for two reasons. The biggest issue is that they spread diseases that destroy a hive. The second reason is that they feed on the bees' fat bodies, which becomes a major issue if hives go into winter with a big mite load since bees rely in part on those reserves to make it through til spring.

So we don't like varroa mites.

There are several ways to test for them and to treat them. My preferred methods are alcohol wash to test and formic acid to treat. 

The alcohol wash does kill bees along with the mites, but a sample of 300 out of a hive of 30,000 is a small sacrifice that will be quickly replaced by new bees. Counting the mites that end up in the bottom of the alcohol cup gives you an estimate of the infestation: 3 mites per 300 bees equals 1 percent. The rule of thumb is anything about 3 percent is cause for alarm.

This year's early mite washes showed few mites. By the summer wash last week, the hives were definitely showing mites. Most were in the 1-2 percent range, but White Hive's infestation was out of control! In fact, it looks like most of the hive vamoosed when the mite load got too high, which is not uncommon. The bees that remain will have to be merged with another hive, it appears.

Treatment protocol calls for using formic acid patties placed across the hive frames. The patties off-gas, emitting formic acid, which kills the mites while mildly irritating the bees. White Hive's dose is 2 patties for 14 days. After that, I'll test again and see how things look.

White Hive has been one of my best hives for size and honey production, although both of those things appear to have slowed down possibly because their mite load. Hopefully, things will return to normal soon.