Wednesday, April 13, 2016

Managing small hive beetle in the sub-tropics

Even though beekeepers in Australia are lucky enough not to have varroa mites, we do have other pests to deal with. One that causes us particular trouble in the sub-tropics is the Small Hive Beetle (SHB) Aethina tumida.  When I started reading about natural beekeeping I was quite shocked to find out that beekeepers use pesticides in their hives.  It seems counterintuitive to use a chemical in a beehive that is designed to kill insects.  However I soon learnt that this is common practice for many commercial beekeepers.  Pesticides are used to control varroa mites in other countries and we have pesticides approved here to use on SHB.  Hence the need for "natural" beekeeping methods, which is beekeeping without chemicals.

eight acres: How we control small hive beetle without chemicals


Would you put pesticide in a beehive?
Pete and I believe that there is no point keeping bees if we are going to use chemicals on them (we believe that about all the animals on our farm and the crops we grow).  The only problem is finding information about how to farm or keep bees without chemicals, as all the commercial farmers and beekeepers are using chemicals and all the research funding is directed that way.  We have had two commercial beekeepers tell us to just use the chemical baits, so it seems to be widespread in the industry here.  No doubt traces of these chemicals end up in the honey and the beeswax, and most people would have no idea, just assuming that honey is a natural product.  There is no testing of honey to ensure that it is safe for consumption.

It seems that within the beekeeping community (both hobby and commercial) there is greater resistance to the use of chemical (compared to farming) and there are a few chemical-free products developed.  Maybe beekeepers are too cheap to pay for the chemical baits, or maybe they see the contradiction of using chemicals to kill insects in a beehive.  Either way, we have a few chemical-free options available and the best part is that they are cheap, reusable, safe for us and bees and we can use all of them at the same time in our hives.

What do small hive beetle do to a hive?
The SHB is a problem in our beehives because it lives in the hives, lays its eggs in the hives and the larvae borrow into the honeycomb, feeding on bee larvae (baby bees) and ruining any honey stores.  The bees work hard chasing the beetles, which distracts from other hive activities, and if they find too many beetles in the hive, the bees will leave.

This has happened to us once already.  We added a super (a second box) to a hive before it had really filled the brood box (bottom box).  The bees had too much space to patrol and could not control the beetles.  One day we opened the hive and nearly all the bees had left, the hive was instead full of beetles.  In summer, when the beetles and the bees can both breed quickly, we have to check our hives regularly (weekly!).  If the bees run out of space they will swarm, but if they have too much space the beetles will take over and the bees will leave.  Its a tight balance, but if we support the bees, they can win, we now have eight strong chemical-free hives to prove it.  (Note that checking the hives this often goes against natural beekeping principles of leaving the bees alone, but this is the only way we can know if they need more or less space to keep the SHB under control).

Chemical-free small hive beetle traps
The bees have a natural instinct to chase the beetles, and they respond by hiding in dark corners.  The chemical-free traps help the bees by providing a deadly hiding spot for the beetles.  They come in two forms, the first is the fluffy-backed lino, which the beetle will stick to.  We buy traps that slide into the side of the hive (called TK traps in Queensland, sorry no website, but your local beekeeping supplier will have them).   You can also get versions that sit on top of the frames.  As you can see from the photos, the SHB sticks to the fluff (as well as a few bees).  The other type of trap is placed either at the bottom or top of the hive and provides a reservoir of either vegetable oil or diatomeceous earth (DE) with small slots into which the beetle will fall and drown or desiccate respectively.  We use the DE as its easier to work with and doesn't spill.

the TK trap is made from fluff-backed lino that slides into the side of the hive box

Both traps are filled with DE - the black one slides into the bottom of the hive,
the silver one slips into the top between two frames

The SHB also has a stage in its lifecycle where it leaves the hive to pupate, and there are a few traps around that aim to catch the larvae as its crawls out of the hive.  We have been thinking about using DE in the soil around the front of the hive but haven't figured out the best way to do this yet.  We want to try one of the mesh hive bottom boards too.

As well as putting one of each of these traps in every hive box, we try to keep our hives strong by not taking too much honey at a time and by making sure that they never have too much empty space.  One difficulty is buying bees, as most from commercial beekeepers will have been raised in hives with chemicals, and so are not bred to naturally resist the SHB.  Actually we bought a hive with a chemical trap in the bottom, which I promptly removed.  There seemed to be just as much beetle activity in the hive as any of our other hives.  It does make me think that the chemicals are not completely effective (just breeding stronger beetles) and that careful management is still required, even if chemicals are used.

I hope that we are eventually breeding stronger bees this way and as long as we don't have varroa mites in Australia, we should continue to use natural chemical-free beekeeping methods.  Now next time you buy honey from a local beekeeper, ask if they put chemical baits in their hives.  Its one of those things you didn't want to know you needed to know, because you might have a hard time finding chemical-free honey in sub-tropical areas with SHB problems.  If you find a chemical-free beekeeper, tell them they are doing a great job and buy lots of honey from them!

Did you know that beekeepers put chemicals in their hives?  Do you buy chemical-free honey?  How do you manage SHB and other pests?

NB beekeepers may also dose hives with antibiotics to prevent European Foul Brood disease, but that is another story....

5 comments:

  1. Hi Liz, Good post thank you. We went to a bee keeping workshop on the weekend and are now looking forward to getting a couple of hives in the spring. Enjoying your comments and information on this topic.

    ReplyDelete
  2. Good post Liz and something I am sure not many people think about when buying honey. Awareness is the key.

    ReplyDelete
  3. This is fantastic. I'm so glad you're finding ways to manage it naturally.

    ReplyDelete
  4. We never use chemicals in our hives. We use the diatomaceous earth traps and have a sheet of flocked lino in the top of the hive. They see to be at a manageable level and this keeps them under control somewhat. I squish any I can when we have the hives open too.
    I agree that keeping strong hives is very important. Like all things, if they are healthy and happy, they are much more capable of dealing with a problem if it arises.
    Happy beekeeping
    Tracy

    ReplyDelete
  5. Excellent post Liz. I discovered SHB in the hive I lost, and although they didn't seem to be significant in that hive in terms of numbers and damage, it was still an alert to me that I needed to become proactive. Like you, we don't use chemicals but the only alternatives I could find were the oil trays. I'll look into the other options! Strong colonies always seems to be the answer, but I don't know how the beekeeper can help with that.

    ReplyDelete

Thanks, I appreciate all your comments, suggestions and questions, but I don't always get time to reply right away. If you need me to reply personally to a question, please leave your email address in the comment or in your profile, or email me directly on eight.acres.liz at gmail.com

Never miss a post! Sign up here for our weekly email...

Related Posts Plugin for WordPress, Blogger...

Suggested Reading