Slow bee paralysis virus is among the viruses transmitted by Varroa. Its name refers to the slow course of the symptoms.

The picture

Unlike the acute paralysis viruses, which can collapse a colony quickly, this virus develops slowly:

• Gradual paralysis, typically beginning with the front pairs of legs
• Bees moving with difficulty
• The infected bee initially appears normal
• Symptoms appear only late in the bee's life

Why slow is dangerous

An infected bee looks and behaves normally for a long time. She flies, forages and works.

The infection therefore goes unnoticed while it spreads through the colony. By the time symptoms are visible, the burden is already high.

The role of Varroa

Without the mite this virus generally stays below the threshold.

The mite changes two things: it introduces the virus directly into the haemolymph, bypassing natural barriers, and it weakens immunity by damaging the fat body.

Diagnosis

Not determinable in the field. Paralysed bees moving with difficulty also occur with chronic bee paralysis, with poisoning and with tracheal mites.

Confirmation requires laboratory testing.

Control

No product acts on the virus. The only genuinely effective measure is keeping Varroa under control.

• Measure regularly and act above the threshold
• Measure before winter bees are reared
• Provide varied pollen
• Work with lines showing strong hygienic behaviour

What to remember

Knowing the name adds little. What counts is that virtually all serious virus pictures trace back to one manageable factor: mite pressure.