Wasps at the beehive · protecting your colony in August
Somewhere around mid-August the mood at the beehive changes. Where you saw bees calmly flying in and out before, you suddenly see wasps scouting the entrance board. Some even make it inside. And if you have a weak colony, it can be robbed empty within a few days.
This is not rare · it happens every year to thousands of Dutch beekeepers. Those who act in time lose no colony. Those who ignore it may end up with an empty hive.
Why August is the problem
Wasp colonies reach their largest size in August · 5,000 to 10,000 workers in an average nest. At the same time something important happens inside the wasp colony: the queen stops laying eggs and no new larvae are produced. For the workers that is crucial, because until then they got their sugar from the secretions the larvae released.
Suddenly those thousands of wasps have to find their own sugar. And where is a lot of sugar concentrated? In a beehive. Twenty kilos of honey within reach, guarded only by a handful of guard bees.
On top of that the nectar flow declines in August · fewer flowers, less nectar, so bees are also less active outside. The colony 'shrinks' inward and sometimes defends itself less well than at summer peak.
Recognise the culprits
Not every yellow-black visitor at your hive is the same. Distinction matters for what to do about it.
- Common wasp (Vespula vulgaris) and German wasp (Vespula germanica) · these are the standard troublemakers. About 1.5-2 cm, bright yellow with black markings, narrow waist. They come in numbers and actively enter the hive.
- European hornet (Vespa crabro) · larger (2-3.5 cm), orange-brown coloured, no bright yellow tones. Catches individual bees at the entrance but rarely robs a whole colony. Protected in the Netherlands · do not exterminate without reason.
- Asian hornet (Vespa velutina) · black with yellow legs and one orange band. Often hovers stationary in front of the entrance and picks bees from the air. Notifiable · this is a different story, see the separate blog about it.
- Honeybee itself · narrower waist, more brown than yellow, hairy body. If you suddenly see masses of 'bees' fighting at another hive, it can be robbing by other colonies. That is sometimes harder to deal with than wasps.
When is it really a problem
A few wasps at your hive is normal. Signals it is getting out of hand:
- Persistent invasions · 10+ wasps at once at the entrance
- Bees fighting or dying on the entrance board
- Bare honey cells just inside the entrance (wasps rob from the edge)
- Particularly restless behaviour at the entrance, even early morning
If you see this, it is time to act. Waiting is rarely rewarded.
Five measures that work
1.Reduce the entrance · do this today. Close the entrance to max 5-8 cm wide. For weak colonies even just 2-3 cm. That is enough for bees to fly in and out but the number of points guard bees must defend drastically shrinks. This is by far the most effective measure · often it suffices.
2.Place a wasp trap · but the right way. A classic wasp trap (beer bottle with beer and jam, or a commercial trap) does not belong near the hive · that actually attracts more wasps. Place it at least 10 metres away, ideally between you and the nearest nest location. That way you intercept wasps on their way to the hive.
3.Combine weak colonies. Combining two weak colonies into one strong colony is almost always better than trying to save two weak ones separately. Remove the weakest queen, put a sheet of newspaper between the two boxes, and the colony sorts itself out within a few days. A strong colony defends itself; a weak colony cannot.
4.Feed only internally · never open. If you feed (sugar syrup for winter), do so via a feeder above the hive with a lid on it. Open sugar water in the garden or next to the hive starts acute robbing behaviour · not only from wasps but also from other bee colonies.
5.Only find and remove nests if you know where. If there is clearly a wasp nest in your garden or under your roofline, removal by a professional (or yourself with good protection, late evening) is a structural solution. But randomly searching nests in the neighbourhood makes no sense · wasps fly kilometres.
What you especially should not do
- No toxic sprays near the hive. The bees also come into contact with it. Stay far from chemicals near your colony.
- No wasp trap directly at the entrance. Attracts exactly what you want to repel.
- Don't open the hive on hot August days. That is exactly the moment robbing derails · honey scent wafts out, wasps and other bees come for the opportunity.
- Don't 'strengthen' a weak colony by giving honey. Sounds logical, works counterproductively · attracts more robbing.
- Don't panic-chase every wasp. A few wasps are normal, let your bees do their work.
Strong colony versus weak colony · this is the core
The big insight in wasp attacks: a strong colony saves itself, a weak colony does not. If you have one colony and it is strong, you often don't have to do more than reduce the entrance. If you have several and one is clearly smaller (perhaps from a late swarm), that is the colony where the problem will occur.
The trick is not to figure this out only in August. In June and July you already saw whether a colony was struggling to grow. That is the moment to decide: strengthen, combine, or accept it may not survive. In August the time to fortify is over.
If it is already going wrong
You arrive at the hive and see thousands of wasps (or strange bees) fighting on the entrance board. What now?
1.Close the hive immediately. Entrance fully shut, even if it means 24 hours without flying in and out for the bees. Better than an emptied hive.
2.Move the hive at least 3 km away (to a fellow beekeeper) for a week or two. The robbing stops as soon as the hive is gone.
3.Wait until wasp pressure drops (after a cold front or end of September) before returning.
4.Evaluate. A robbed hive almost always means: the colony was too weak for that time of year. Learn from it for next season.
Frequently asked questions
When should I reduce the entrance?
When you see the first wasps persistently at the entrance · in the Netherlands usually somewhere between mid-July and mid-August, depending on weather and region. For weak colonies: earlier rather than later. Reducing can always be done, enlarging has no urgency.
Do wasp traps really work?
Yes, but only as a supplement and at distance from the hive (at least 10 metres). A trap alone saves no colony · a small entrance and a strong colony do. See it as a lock next to the guards.
What is the difference between robbing by wasps or by other bees?
With wasps you clearly see different insects: smaller, yellower, less hairy. With bee robbing you see bees tumbling around at the entrance and full bees flying off. Bee robbing is often more destructive because they are smarter and more numerous. Approach is largely the same: close entrance, move hive if urgent.
Should I exterminate wasp nests in the garden?
Only if it is really close (< 10 metres from the hive) and demonstrably that nest is responsible for your issue. Wasps also serve a useful function · they eat mosquitoes, flies and aphids. Removing a nest without reason is not necessary.
Can a colony defend itself against wasps?
A strong colony (10+ frames occupied, many guard bees, active queen) defends itself excellently, provided the entrance is small enough. A weak colony (3-5 frames occupied, thinned by swarm or disease) stands no chance, even with a small opening. Colony strength is ultimately the best protection.
To close
Wasps at the beehive belong to August. They did not arise to bother your bees · they do what every hungry living species does: search for easy calories. Your task is not to exterminate them but to make the door small enough so your bees can handle them.
A daily look at your hive in August · five minutes is enough · and you see early enough when something goes out of balance. That is worth more than any wasp trap.
Are you having trouble with wasps at your hive this year, or discovering something clever that works? Share it on the forum under Bee Health & Diseases · other beekeepers learn from your experience.