Varroa surveillance planning
Before we explore varroa surveillance techniques you need a plan and structure. Surveillance should not be carried out ad hoc or on a whim as it will ultimately lead to poor outcomes. The worst of which is being a false sense of security that you don’t have varroa, when in fact it was your surveillance plan that actually failed to find it. This is dangerous to both your hives but also hives surrounding you. You will recall from part 1 that proximity is the biggest predictor of varroa spread.
1. Know where your hives are and make then identifiable for record keeping.
2. Plan for regular spot checks across all hives.
3. Understand what methods you’ll be using to check for varroa – and know their limitations.
4. Record key information from all hives inspections and visits.
5. Engage your neighboring beekeepers.
6. Practice good hive hygiene and follow all state biosecurity laws.
7. Know what to do if you find varroa.
Know where your hives are and make then identifiable.
Plan for regular spot checks across all hives.
- If you have fewer than 8 hives at a site, check all hives. For larger apiaries check 25% of hives.
- A rolling mite inspection program can be effective. Plan to check a portion of you hives every visit over the month you will see them all. This can be more effective than inspecting all hives on a single day once a month.
- If you are a large beekeeper and are only inspecting a portion of hives change which hives are checked each inspection. Drift collector hives should be checked regularly.
- Ensure the hives you choose to check represent all you’re apiaries, meaning the are from a spread of sites and geographies.
Check your hives monthly’s as a minimum. If you hear of infections in your vicinity increase your checking frequency and intensity.
Understand what methods you’ll be using to check for varroa – and know their limitations
The most common methods are Alcohol washes, Sugar shakes, Sticky boards and Drone checks. See part 3 for details on how to perform these tests. The aim of a surveillance plan is to find varroa as early as possible not to quantify it or control it.
Bee wary of experimental or unproved techniques. During an outbreak while we are hunting down and eliminating varroa the two most important consideration are how reliable is this test I’m doing (is it well studied and understood) and how sensitive is this test (will it detect varroa early). All the techniques outlined below are scientifically proven and used smartly can create a strong detection programme.
These work by taking a sample of bees and washing them with ethanol. This detaches phoretic mites from the bees and they can then be counted. You will recall the majority of mites are in the reproductive stage. With low level or early infections, you are not likely to have many phoretic mites. Therefore, an alcohol wash will only reliably detect mites when there are several hundred in a beehive. With low mite numbers the chance of your sample containing a mite decreases. This is a good crude tool to apply across all your hives.
Recommended usage – monthly for low-risk hive surveillance.
This also works by detaching phoretic mites. The confectioners’ sugar encourages grooming behavior which causes the mites to drop. This too is only reliable when there are several hundred mites in a hive. We recommend that sugar shakes be conducted in conjunction with drone brood inspections to improve their effectiveness.
Recommended usage – monthly for low-risk hive surveillance.
A sticky board is a mat that is placed in the bottom of a beehive. Mites naturally falloff the bee over time (death or grooming) and then get stuck on the sticky board. When a beekeeper checks the board they can look for varroa that have accumulated over the past week. The varroa can be easily identified with a magnifying glass or by the naked eye. See example images below.
This method is better at detecting low level varroa infections as it samples the entire hive and can be left in for long periods of time. To increase mite drop confectioners’ sugar can be sprinkled on the top bars to encourage bee grooming.
Recommended frequency – Continuous for high-risk hives.
Leave the boards in a check and replace as needed. We recommend pairing this with a knockdown treatment to increase drop rates e.g. chemical controls or confectioner sugar.
Drone brood inspections
Take a wax uncapping tool and scrape an area of drone brood open to expose the pupa. Expose several hundred at a time. You are looking for the breeding varroa that may be inside these cells. They look like small brown dots 1.5 mm in size. You may see either males or females. Specific drone frames can be inserted into the hive to encourage drone laying.
Recommended frequency – monthly for low-risk hives along side either of the shaker methods.
Varroa mite morphology – What a mite looks like
Females – see in washes or sticky boards
- 1.1 mm long, 1.5mm wide
- Flattened bodies, ovoid shape
- Dark brown/red in colour
- Hard protective outer layer.
Males – seen in brood inspections
- 0.7mm long, 0.9mm wide
- Rounded bodies
- Yellow/white in colour
- Will not be seen as phoretic mites
Engage neighbouring beekeepers and follow all state laws
Now that you understand the way varroa spreads it is clear that varroa surveillance involves everyone. Check that your neighbours are on top of their surveillance program and help them out if they aren’t. Report abandoned hives and maintain good records of all hive movements. Before moving any hives inspect them for varroa.
Example surveillance protocols
These are examples and not specific guidelines. Please check with your state or local authorities that your surveillance measures meet your responsibilities as a beekeeper.
For a hobbyist beekeepers
1. Register all your hives.
2. Check on the DPIs website if you are in a Varroa Emergency zone
a. If so, contact DPI and follow their advice
3. Begin regular washes of hives and record results.
a. Check ALL your hives individually every cycle.
4. Keep up to date with the latest outbreak information.
a. If varroa is close, but you are not in an Emergency Zone consider transitioning to sticky board for a more intensive monitoring program.
5. Report any mites you find immediately.
For a commercial beekeeper
Please contact the Ecrotek Australia team, generalised advice may not be suitable for all commercial beekeepers.
What to do if you are unable to implement a surveillance program in a high-risk area
The beekeeping industry employs thousands of people and is a livelihood for many. We know varroa can be hugely detrimental and a burden on beekeepers. If you are unable or unwilling to be part of the communal initiative to detect and eradicate varroa the most product option is to euthanise your hives or give them to a beekeeper who is willing. Abandoned and untreated hives can lead to consistent reinfection and makes the job of responsible beekeepers a magnitude harder.
Please see our current Varroa products here