Infected Colonies

Classification of AFB

Classification of AFB

A colony is said to have AFB when one or more of its larvae are fed enough spores to kill them.

In some colonies, the beekeeper may never be aware that a diseased larva or pupa has been produced. The house bees may remove diseased larvae as fast as they become infected, so all the beekeeper sees is a spotty brood pattern (Fig. 13).

Figure 13: Spotty brood pattern

The house bees may do this effectively enough to eliminate the infection from a colony.

Infections where no visual symptoms appear in the colony are called “inapparent” or “subclinical” infections. However, it is not possible to differentiate between a colony that is contaminated with spores and has no diseased larvae or pupae, and one that has a subclinical infection.

We may never know how many colonies develop subclinical infections of AFB and eliminate the disease by themselves.

Many beekeepers have noticed colonies that appear to recover from AFB. Having found a colony with a single diseased larva or pupa, they check the colony a few days later before burning it and are then unable to detect any sign of the disease.

It pays to be vigilant

The danger for beekeepers is that although some colonies may eliminate the disease completely, for other colonies the recovery will only be temporary. Because there may still be large numbers of AFB spores in such colonies, they may develop visual symptoms of the disease at a later date, and the symptoms will be severe enough to destroy the colony.

Obviously, colonies with subclinical infections are a factor in the spread of AFB. Even if beekeepers carefully check every frame of brood for diseased larvae and pupae before removing frames to place in other colonies, they cannot guarantee that they are not going to spread the disease.

AFB Quiz
Take the AFB 5 minute quiz

How well do you know what you need to know about AFB and beekeeping? Take our short quiz and find out.

AFB Videos

Our videos cover everything from your legal obligations to how to recognise AFB, collecting cell and bee samples and more.

AFB Symptoms

There’s a lot of good information here, telling you everything you need to know about recognising AFB: the visual symptoms, smell of AFB and more.

AFB Inspection and Diagnosis
Inspection and Diagnosis

Successfully eliminate AFB by telling the difference between symptoms of AFB and other brood diseases in the hive. We tell you the best methods for inspecting your hives.

The Law

New Zealand beekeepers have a number of legal obligations that must be met regarding AFB disease. Read the shortened list in summary, here.

AFB Elimination

Most hives become infected because bees, honey or equipment have been put into a hive from another hive that is infected with AFB. Lower your chances of an  AFB infection by reading this section.

AFB Course Info
AFB Recognition Course Info

Find out when the next AFB Recognition and Competency Courses, or Refresher Courses are available. These are held throughout the year in various New Zealand locations across the South Island and North Island.

The AFB App

Follow the link below to open the App. Once open to save to your device you need to bookmark the URL on your phone so you can find it easily again. Please click here to open.