Calistrip® Biox (5 beehives)

01 · WHEN TO APPLY IT

With brood at its lowest and the bees still moving

Oxalic acid does not penetrate the capped cell, so it does not reach the varroa inside the brood: that is why the SPC says to use it in the absence of brood or with brood at its lowest levels. And because it acts only by contact, it has to go in before the winter cluster forms, while the colony is still moving.

One point worth knowing: the dossier provides no clinical data for conditions other than autumn in southern Europe.

02 · HOW IT GOES IN

Two strips, between food frames, six weeks

The authorised dose is two strips per hive — 12.88 g of oxalic acid dihydrate — hung between two food-storage frames, where the bees show most movement and with free access to both faces. The fold lines adjust them to long strips, about 30 cm, or short ones, about 25. And three rules the SPC states without qualification: do not cut them, do not reuse them and remove them after six weeks.

03 · THE HONEY

Zero days of withdrawal is not the same as being able to harvest

This is what gets misread most about this product. The declared withdrawal period for honey is zero days, but the same SPC adds three prohibitions: do not use during the honey production period, do not extract honey from the brood chamber and do not harvest during the six weeks of treatment.

And the one that sets your calendar: it cannot be used with the supers installed, because its effect in the presence of supers has not been studied. They come off before you start.

04 · HOW IT WORKS

What is known and what is not

It spreads through the colony by body contact and by trophallaxis. On the mechanism it is worth being straight: the SPC states that the mode of action against varroa is not well understood, that the effect is attributed in part to the mites' sensitivity to acid pH and that it is believed to immobilise calcium. On the kinetics there are figures: in the haemolymph the concentration falls by 80 % at 72 hours.

05 · PRECAUTIONS

Irritant, and not to be mixed with another acaricide

It can irritate skin, eyes and mucous membranes: avoid contact and wear the clothing and gloves usual in beekeeping. On skin contact, wash with soap and water; in the eyes, with plenty of clean water, and if the irritation persists see a doctor, taking the leaflet.

In practice: treat every colony in the apiary at the same time, do not use it alongside another acaricide, and alternate in successive treatments with a varroacide of a different mode of action to slow resistance. The SPC also recommends a mesh floor of about 3 × 3 mm. Used strips go to a medicines take-back system, not in the bin.

06 · BEFORE YOU BUY

It is registered in Spain only, and we dispense it as a retail establishment for veterinary medicines, no. V-48-VC. It is not subject to veterinary prescription. Shelf life 18 months, and 6 months once the sachet is opened.