【庭院養蜂】殺蟎蟲最簡單最便宜的方法（英文版）

Oxalic acid vaporization (OAV) is commonly used for controlling Varroa mites in beekeeping. There are a great number of devices for vaporizing oxalic acid. Some are expensive. Some are cheap, but they all work similarly, that is, to deliver oxalic acid vapor into the beehive to kill Varroa mites on bees.

I considered buying an expensive unit, but decided against it eventually. For a backyard beekeeper like me with only 5-6 colonies, I figured my system is better. It is cheap, scalable, parts replaceable and very reliable. It may not be as super fast as the expensive models, but it will never clog up. Plus, I never have to wear a respirator while administering oxalic acid. Oxalic acid vapor can do serious damage to your lungs if inhaled. Some oxalic acid vapor is getting to your lung if you can smell acid. Can you smell acid even when you have a respirator on?

Here is my setup. I have four oxalic acid vaporizers. Got them on a Black Friday. Total cost is about $100. I found a long time ago that the bottleneck in using this type of vaporizer is waiting for it to cool down after use. Oxalic acid crystals will sublimate quickly if added too soon when the vaporizer is still hot. With 4 vaporizers, no waiting is needed. A lawn mower battery is used for power, therefore no extra cost. Here is how my setup works.

1. Find a day when temperature is between 40-50 F. This is the best temperature range for vaporization. Too cold, honey bees cluster too tightly. As a result, oxalic acid vapor may not penetrate the cluster deep enough to effectively kill mites. Too warm, a lot of bees will be out foraging, thus mites on these foragers will escape the fate of being killed.

2. Fill heating elements with oxalic acid. The optimal amount of oxalic acid is debatable. I am usually on the generous side with the amount.

3. Remove entrance reducer. The custom-made reducer doubles as a mouse guard in winter. It is very cheap and very effective.

4. Insert one vaporizer into each hive. Cover the entrance with wet T-shirt for more effective fuming.

5. Connect vaporizer to power. A fully charged lawn mower battery has enough juice for 6 colonies. A higher capacity battery will be ideal. Maybe a gift from Santa next year. I have an AC to DC converter and an adapter just in case.

6. Stay away from the hive. It is too close if you can smell acid vapor. Wait until vaporization is complete. It usually takes 4-5 minutes.

7. Move the battery to the second hive. Connect power to the second vaporizer, which is already in the second hive.

8. Move the battery to the third hive when the second one is done. Move the battery to the fourth hive when the third one is done. By the time the fourth hive is being worked on, the first two vaporizers should have cooled sufficiently for a second dose of oxalic acid. And the process continues until all hives have been fumed and mites assumed dead.

It took less than one hour to fume 6 colonies from setup to putting everything away. It may not be as fast as some super-fast instant vaporizers, but the pros of this setup are obvious: cheap, reliable, never have to clean clogging in the expensive units, all parts easily replaceable, no respirator needed.

As a result, this setup might be the best overall OAV system for a beekeeper with a small number of colonies. Please comment below and share your opinions.
--------------------------------------------------------

--------------------------------------------------------
【博文自薦】
自製糖板，冬天喂蜜蜂（英文版）
蜜蜂是怎麽交配的？
--------------------------------------------------------