Varroa Easycheck

01 · THE SAMPLE

Around 300 bees off a brood nest frame, and no queen

The white basket carries two marks: the upper one is about 300 bees and is the one to use; the lower one, about 200, is only for nucs and weak colonies, because with fewer bees you miss just the low infestations you want to catch in time. Take the bees from a frame in the brood nest, always the same kind of frame so the readings compare, and never from the entrance or the super. The trick that saves grief: shake the frame into a wide tub, wait half a minute for the older bees to fly off and check the queen hasn't dropped in; then fill the basket to the mark with the young bees, no drones.

02 · THE THREE METHODS

Alcohol for the figure; sugar or CO₂ to keep the sample alive

For the alcohol wash, half-fill the jar, drop in the basket and swirl it round for a full minute without tipping it over: this is the reference method, and if you rush it or the alcohol is watered down the count comes out low. The sample is lost, under 1% of the colony. For the sugar roll, two heaped tablespoons of icing sugar, one minute rolling, three minutes resting in the shade, then shake it out over the lid; most of the bees go back alive, but the count runs low, more so in damp weather or during a flow. With CO₂, five seconds of gas through the holes, ten seconds' wait and fifteen of gentle shaking: the quickest, and the sample goes back alive; count the mites on the lid and in the basket as well, and take it as read that it runs low. For the figure that decides a treatment, alcohol.

03 · THE SUM

Divide by three and you have the percentage

In good light, count the mites in the base (brown, oval and all alike) and divide by 3 if you took 300 bees: 6 mites is 2%, or 2 mites per 100 bees; 15 is 5%. It's an estimate for comparing hives and dates, not for arguing over decimals, and a zero isn't a clean hive: it's under 1%. As a guide, the one we publish in our varroa diagnosis post: around 1%, measure again within two months; 3%, treat within the month; over 5%, don't wait. And don't count the apiary as checked on the strength of one hive: wash around ten per site; there is always one well above the rest.

04 · WHEN TO MEASURE

Four moments worth the trouble

Early spring, to know where you are starting from; with the hive full of brood most of the varroa is under the cappings, and a single mite in the base is already a warning. Between flows, so it does not run away from you while you cannot treat; in the middle of a flow the sugar cakes up. Late summer, the reading that decides the treatment before overwintering. And one or two weeks after taking the product out, same hives and same sample size: measuring afterwards is what separates treating from assuming, because every treatment leaves some behind.

05 · BEFORE YOU BUY

CO₂ needs the Véto-pharma injector and 16 g cartridges, sold separately: one cartridge does three to five hives, and check on its page whether it takes threaded or unthreaded cartridges. For the alcohol wash, methylated spirits or 96% alcohol will do, and so will winter windscreen washer fluid; not soap, the foam hides the base. Filtered, the liquid lasts around ten washes.

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