Symptoms, Treatment And Prevention
Tropilaelaps mites are external parasites that move quickly among honeycombs and feed on the haemolymph (blood) of bee larvae and pupae. They’re native to Asia, but pose a significant threat to beekeeping worldwide – if they ever reached Australia or New Zealand, they would cause substantial damage to our honey industries.
Tropilaelaps mites haven’t reached our shores yet, but that doesn’t mean we should be complacent. Our border security isn’t foolproof and there’s always a risk of pests spreading through imports. It’s best to be prepared and understand exactly what to look for – just in case.
Here’s everything you need to know.
Characteristics: What does the Tropilaelaps mite look like?
The mites are about 1mm long, red-brown with four pairs of legs. They’re often likened to Varroa mites, but the Tropilaelaps mite moves faster, while the Varroa mite is bigger and has a wider body. Tropilaelaps mites could be considered a more damaging pest, given that their life cycle is shorter, with a much higher reproduction rate. Because of this, there can sometimes be 25 Tropilaelaps mite to every single Varroa mite in a hive.
Adult mites lay their eggs in the brood cells of European honeybee larvae, feed on developing honeybees and reproduce inside the brood cells. When the adult bee emerges from its cell, it will be stunted.
Symptoms of Tropilaelaps mite
A Tropilaelaps mite infestation will have similar symptoms to Varroa mites, but there are a few differences.
Here’s what to look for:
- High brood mortality
- Irregular brood patterns
- Weak adult bees with missing wings
- Bees with deformed or missing legs
- Dead brood remaining uncapped in cells
- Unusually small abdomens
- Reduction in bee population
- Bees absconding from the hive
- Bees crawling at hive entrance
- Paralysed bees at hive entrance
In severe cases, bees may swarm frequently, which allows the mites to spread easily. Up to 50 per cent of the brood may die, in which case an unsettling smell of the dead brood will surround the hives.
A diagnosis of this parasite can only be done visually.
If you suspect your hive is infested, try this simple test:
- Take about one cup or container of bees (about 300 individuals) from the colony
- Put them into a large jar, add 3 teaspoons of powdered sugar, and put a screen on top
- Shake the jar onto a white piece of paper, and the mites will fall through the screen.
Controlling Tropilaelaps mites
Strict border controls and quarantine requirements are vital to protect our country from these mites. There are strong procedures in place to guard New Zealand and Australia from unwanted pests – The National Bee Pest Surveillance Program in Australia – an early warning system to detect exotic bee pests – and the government bee biosecurity programme in New Zealand.
Although the risk of Tropilaelaps spreading to our country is small, we still need to be aware and monitor any changes within our hives. There are some things you can do to minimise the risk of infestation or spread, habits that can also help prevent the spread of other bee pests and diseases.
- Clean all your beekeeping tools thoroughly and regularly, including beekeeping clothing.
- Check your hives frequently, and report any unusual signs to your local pest control authority.
- Maintain a healthy, clean and vibrant colony to give your bees the best chance of fighting off pests
Although the risk of Tropilaelaps mites spreading to Australia or New Zealand is low, it’s potentially devastating. We can all do our part to protect our bees and our valuable honey industry.
Want to find out more about bee pests and diseases? Check out our articleshere.