Watch-bees on the job

How much are bees worth to you?

Well, did you know they earn an estimated $4-$6B for Australia every year? Another way to look at it is – what price would you place on cashews, almonds, macadamias, strawberries and avocadoes? Among many others, these crops rely on bees for pollination.  In fact, around one in three bites of the food we eat owe its existence to bees, which is why it is a concern to learn that bee populations around the world are in trouble.

Bees on a frame

Healthy bees at work

Enter Destructive Varroa

Varroa mite (Varroa destructor) is in all beekeeping countries except ours. These sesame-seed-sized mites attach themselves to bees and suck their haemolymph (insects’ version of blood), making the bee more vulnerable to disease. No country has been able to eradicate Varroa once it’s established.

Varroa has been implicated in collapse of bee colonies. Adult worker bees suddenly leave the hive, dying somewhere else. The colony then falls apart. The underlying cause is often unclear, but devastated hives often contain Varroa mite. This may only be a coincidence, but it’s another reason to keep Australia Varroa mite-free as long as possible. Colony collapse has become a major problem – particularly in the US.

The good news is we’re unaffected – so far. The bad news is that when (and it is when, not if) Varroa mite arrives in Australia, local bees haven’t been exposed to it, so they’re extremely susceptible. There have already been a couple of scares in 2012. Varroa-carrying bees were found living in the loading cranes of a ship berthed off Sydney.

Bee pupae infected with Varroa mite

Varroa mite on bee pupae

Australia is currently free of Varroa mite but not of Asian honey bees which is their natural host. We’re already on alert, which is why horticultural industries, the honeybee industry and the Australian Government created a National Bee Pest Surveillance Program, managed nationally by Plant Health Australia.

Unfortunately no amount of surveillance can guarantee pests are kept out, so an early warning system is necessary.

The most likely entry point for Varroa mite is through Australia’s east coast ports, especially from vessels from New Zealand and South-East Asia.

The National Bee Pest Surveillance Program now has 126 sentinel hives. These are hives of healthy European honey bees that are placed at high-risk locations, an average of six per location. These hives are tested every two months using mite-killing chemicals, to provide early detection for Varroa mites and another major honey bee pest, Tropilaelaps mites that could be carried by exotic bees on a ship or in the cargo. Samples of bees are taken from sentinel hives every two months.

But how do they know which ports to put the hives at? Enter data analytics.

The shipping news

Working out the best sites for the hives involved taking multiple data sets containing details on exotic bee interceptions, ships involved, ports of origin, destinations and types of cargo carried.

We used a technique called random effects modelling, a way of drawing out the relevant information when the precise characteristics of the members of the dataset– in this case the cargo, the last country of call and arrival port– are not all the same and difficult to quantify.

We started with shipping data. There is comprehensive information on those vessels that have arrived in Australia, when and from where. We matched this with records of exotic bee interceptions – sometimes on vessels, in machinery, or nesting on the outside of containers at ports.  We then collected maps and aerial pictures of all Australian ports, to produce models of potential bee habitats. To know what to put into the models, we had to find out how far bees can swarm (5km maximum for Asian honey bees and 2km for European honey bees). We also had to learn how long a vessel would need to be in port for bees to find a place to swarm to. If there isn’t enough time for scout bees to find a suitable site or a second set of bees to visit and ‘approve’ it, the colony will not swarm. That’s also assuming it has a queen and is a genuine swarm. This was not always possible to establish with confidence from the interception data.

Some ports with desert or industrial areas nearby ports were ruled out because they have no habitat suitable for honey bees that are within swarming range. This also ruled out ports where the berthing location is relatively distant from the coast.

Data were then assessed to establish what cargo came to the more ‘bee-hospitable’ ports, where the vessels arrived from and how long the voyage had been. Voyages of 300 days or longer were excluded on the basis that the bees wouldn’t survive a trip of that length.

The country of origin and type of cargo are also important considerations. Asian honey bees in particular like to nest in nooks in machinery which is subsequently shipped as cargo. These bees are less keen on – perhaps unsurprisingly – the barren hulls of empty vessels.

Asian honey bees

Asian honey bees

All this information and consideration have combined to produce a surveillance system that is likely to use resources effectively as possible and head off exotic and infected bees before they do any damage.

So, next time you’re enjoying a handful of almonds, spare a thought for the bees that pollinated it and for the data analysis that goes into keeping those bees healthy.


Tiny technology creates a buzz

Bee with sensor

Bee with a backpack… of the sensor variety.

By Adam Harper

What if I told you that insects in the environment may be able to tell us about the world they live in? Imagine it; they could reveal changes in climate, the presence of dangerous gases or even the arrival of pests. Now you might think this a flight of fancy and tell me to buzz off, but this may not be so far from reality.

Our new research project is using tiny sensors that act like your car’s e-tag and attaching them to the backs of honey bees.

What the?

You heard right –  bees with a chip on their shoulder, or on their back at least.

These tiny 2.5mm x 2.5mm chips relay data to recorders placed around hives and known food sources. We’re not talking about one or two wired up insects here, 5,000 tags are currently being attached to honey bees in Hobart and released into the natural environment.

And why would our researchers do that?

Collecting bee movement information at this scale is a world first and will allow researchers to generate a four dimensional model (three dimensions over time) of bee behavior and the way these insects move through the landscape. This information is needed on a global scale as wild honey bee populations are  dropping drastically or vanishing all together. In some instances this is because of the parasitic Varroa mite. In others it’s a case of Colony Collapse Disorder, which is believed to be caused by diseases and agricultural pesticides.

CSIRO’s Dr Paulo de Souza leads the project and talks about why it is so important to protect these often feared insects.

“Honey bees play an extremely important role in our daily lives. Around one third of the food we eat relies on pollination and this is a free service these insects provide. A recent CSIRO study showed that honey bees helped increase faba bean yield by up to 17 per cent. Knowing how bees interact with their environment will allow farmers, fruit growers and seed producers to manage their properties using honey bees to increase productivity,” says Dr de Souza.

Man holding bee hive

Dr Paulo with his beloved bees.

The research is also looking at the impacts of farm pesticides on honey bees and how much these chemicals contribute to CCD. Healthy bees means healthy landscapes.

Tagging the bees is only the first stage in the project. The next requires us to make the sensors even smaller, down to the size of a grain of sand so they can be used on smaller insects like mosquitoes and fruit flies.

“We also want these smaller tags to be able to sense environmental conditions such as temperature and presence of atmospheric gases; not just track their location.”

“Further to this the sensors will be able to generate energy from the beating wings of the insects, which will give the sensors enough power to transmit information instead of just storing it until they reach a data logger,” says Dr De Souza.

In short, insects will be real-time ‘swarm sensing’ at a scale never before achieved. Insects could become the canaries of the mines or the sniffer dogs of the airports. Bring on the buzz.

***

Media: Adam Harper,  +61 7 3833 5605  adam.harper(at)csiro.au.


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