Septicaemia is the multiplication of bacteria in the haemolymph of adult bees. Several organisms can be involved, Pseudomonas species being the most often cited.

It is uncommon and closely tied to conditions: it appears where colonies are damp.

How it develops

The bacteria enter through the breathing openings or through damage to the body wall and multiply in the haemolymph.

The haemolymph of a healthy bee is clear. As the infection advances it becomes cloudy and milky — one of the few findings that can be assessed by eye.

Signs

• Segments separating easily. The connective tissue breaks down; a dead bee falls apart when handled. This is the most distinguishing sign
• Cloudy haemolymph. Milky rather than clear
• Bees crawling, unable to fly
• Rapid loss of adult bees
• An unpleasant smell is sometimes described

The separating segments are the practical distinction. A dead bee coming apart in the fingers points to this rather than to other adult diseases.

Conditions that bring it on

• Damp: The principal factor. Wet apiary sites, poor ventilation, condensation
• Poorly drained ground
• Shaded, still positions
• Weak colonies
• Long periods of confinement in bad weather

As with chalkbrood, the disease is often less the problem than an indicator of conditions inside and around the hive.

What to do

There is no specific treatment, and none is usually needed. Correcting the conditions is the approach:

• Improve ventilation. Reduce moisture inside the hive
• Tilt the hive forward so condensation runs out
• Raise the hive off the ground
• Review the apiary site. Dry ground with morning sun makes a marked difference
• Reduce the space to what the colony can warm
• Strengthen or unite the colony

Diagnosis

Definitive diagnosis requires laboratory analysis. In the field, separating segments together with damp conditions is a reasonable indication.

Practical position

Septicaemia rarely requires action in its own right. If it appears, the question to ask is not "which treatment" but "why is this colony wet".