If you snooze, you will lose your bees!

In my role as an NSW Bee Biosecurity Officer, I talk with many beekeepers every week. For the most part these conversations have always been productive and enjoyable and with the odd exception, it is great to help them with advice on how to better manage their bees. However, in the last 2 years or so a lot more calls are coming in from beekeepers who have just lost their bee hives and are not 100% certain why.

When asked what has happened to their hives, the most common initial response has been “because my bees were poisoned” or “all of my bees swarmed”. Whenever one of the BBO team hears that from a beekeeper (or if we see a slide result that was sent to our lab being negative for brood disease) we are now generally considering that varroa may be implicated in the case.

Having a few (or even a few hundred) dead bees around the entrance of a beehive is very common and should not really be all that concerning, as in any normal strength colony, many, many hundreds of bees may die every single day during the season. Generally, most bees die out in the field whilst foraging away from home and are never seen by the beekeeper, but even if just 20-30 old ones died overnight and were pushed out the front entrance that is 150-200 bees a week being dropped out there. If ants, birds and other things don’t remove those bees, then the numbers build up pretty quickly and may appear to be alarming (but mostly they are not).

If, on the other hand there are thousands upon thousands of unwell/dead bees within the hive (often completely filling spaces between each brood comb) and crawling around and twitching at the front of the hive. then it could be from poisoning. If that is the case, then you should contact the NSW Environmental Protection Agency (EPA) as they are the lead agency that handles bee poisoning events. The EPA can allocate a case officer to investigate and advise how samples can be collected so that they can be sent off to a laboratory for sampling. Please note, generally the beekeeper pays for the lab testing, so make sure you are certain that it is poisoning before outlaying all that money to test for the potential chemical responsible.

In many populous parts of NSW varroa has been present for at least the last 18 months-2 years (or longer), so if beekeepers in those areas tell me that they don’t have varroa yet (I still hear that every week, but a visit to the heat map normally shows high mite detections) then generally I know straight away that they are not actually looking. If you are not actively looking, then you are also not managing varroa either!

If you want to keep bees (which is still very achievable now that varroa is here), then please aim to keep them properly. Monitor for varroa frequently, using the most quick and accurate monitoring tool which is an alcohol wash. Forget about using a sugar shake or CO2 method (often promoted because they don’t kill the bees as quickly), as field trials in NSW have shown these methods can be very, very inaccurate. Use an alcohol wash and quickly and humanely euthanise ½ cup (~300 nurse bees) for the greater good of protecting not just that hive but potentially your entire apiary. Unless you are undertaking scientific research you don’t necessarily need to monitor varroa in every single hive within an apiary, as generally you can justify undertaking treatments on every hive in it as soon as you find one that has enough mites to warrant treatment.

NEVER rely on visually spotting mites on bees to determine if you may have mites, or when to treat, as that is highly inaccurate and prone to error! Seeing mites on bees generally means you already have HEAPS of them, so aim to find them with an alcohol wash on nurse bees before it ever gets to that stage!

The important thing is to keep looking regularly and act accordingly when a wash in the apiary shows that hives are experiencing mites above whatever recommended treatment threshold you follow. Then use an approved miticide treatment appropriate to your current conditions to effectively knock down the mite numbers. Don’t snooze, or you will lose your bees.