Varroa and varroosis: what are they?

Bee health is now at the heart of beekeeping concerns and, among the major threats bearing down on them, Varroa destructor holds a central place. This parasite is behind a fearsome disease: varroosis. But then, what is varroa? How does it act? And what are the consequences of varroosis for hives? Let's take stock of this scourge affecting almost all European colonies.

What is Varroa destructor?

Varroa destructor is an external parasitic mite, native to Asia. It spread across Europe during the 20th century and has now settled in almost every hive.

This tiny parasite attaches to the body of adult bees, but above all to larvae and pupae, which it parasitises by feeding on their haemolymph (a vital fluid in insects). This feeding weakens the bees and encourages the transmission of numerous viruses, including deformed wing virus.

What is varroosis?

Varroosis is the disease caused by the infestation of the bee colony by varroa. It shows itself in several ways:

• General weakening of the colony,
• Appearance of deformities in young bees,
• Drop in honey production,
• Possible collapse of the hive in the event of heavy infestation.

It is therefore not a simple nuisance, but a serious pathology, which requires rigorous monitoring and treatment.

How can you recognise a hive affected by varroosis?

The signs don't lie. In the case of varroosis:

• You may observe bees with shrivelled or deformed wings,
• The colony seems less active,
• The brood shows abnormalities,
• The mortality rate rises.

In addition, the natural varroa drop test on a greased board makes it possible to measure the infestation directly. It is recommended to regularly monitor the state of hives, especially at the end of the beekeeping season.

What treatments exist against varroosis?

The fight against varroosis relies on a combined approach. There is no miracle cure, but several solutions make it possible to keep the varroa population under control.

1. Natural treatments

These treatments are often used in organic beekeeping. They notably include:

• Oxalic acid: sprayed or trickled,
• Formic acid: used as a slow-release treatment,
• Thymol: an active ingredient in certain essential oils.

These substances must be used with care and under precise conditions (temperature, stage of the hive's cycle).

2. Medicinal treatments

Active substances such as:

• Flumethrin,
• Amitraz,
• Coumaphos,

are available as strips, solutions or gels. Some require a veterinary prescription. It is essential to follow the manufacturer's instructions to avoid any residue in the honey and to preserve the product's effectiveness.

At Produits-Veto.com, you'll find a specialised range of solutions against varroosis, such as:

• VarroMed (formic + oxalic acid),
• Apiguard (thymol),
• Api-Bioxal (ready-to-use oxalic acid).

Take a look now at our range dedicated to beekeepers.

Why is it important to treat regularly?

Varroa develops rapidly, especially during periods of abundant brood. Without intervention, a heavily infested colony can disappear within a few months.

It is therefore recommended to:

• Regularly monitor the parasite pressure,
• Treat at strategic times, particularly after the harvest and in winter,
• Vary the methods to avoid resistance,
• Renew the queens with more resistant strains.

Do you have questions? – FAQ

In conclusion, varroa and varroosis represent a constant threat to bee colonies. To preserve the health of your hives, a rigorous approach is essential: monitoring, appropriate treatments and prevention are the pillars of sustainable beekeeping.

At Produits-Veto.com, we offer you reliable, well-established products, to fight this parasite effectively and help protect your bees.