Common Wasps (Vespula)

Wasps or yellowjackets (social wasps of the genus Vespula) are among the most common pests in apiaries in late summer and autumn. Individually they are small, but they come in large numbers and persistently, rob the honey of weak colonies and kill their bees. The most effective protection is a strong colony, a reduced entrance and leaving no smell of sugar in the apiary.

What are wasps, and why do they come in late summer?

The species most often seen in apiaries in Türkiye are the German wasp (Vespula germanica) and the common wasp (Vespula vulgaris). Mated wasp queens spend the winter in sheltered places and found a nest on their own in spring. The nest may be underground, in wall and roof cavities or in empty hives; over the summer it can grow to thousands of workers.

Throughout the season the workers feed their larvae with insects and bits of meat, and in return receive a sugary secretion from the larvae. In late summer, as brood production declines, this sugar source dries up; at the same time nectar also becomes scarce in nature. The workers start looking for sugar, and a hive smelling of honey becomes the easiest target. In autumn new queens and males emerge, and with the cold the nest breaks up; only the mated queens survive the winter.

Damage and signs

• Large numbers of wasps constantly patrolling in front of the entrance, landing on it and trying to walk inside
• Bees and wasps grappling in pairs in front of the entrance; dead bees and dead wasps in front of the hive
• Honey cells inside the hive torn open raggedly; the honey super emptying rapidly
• Wasps tearing up and carrying off dead and weak bees, and even brood
• The colony going on the defensive, fewer foragers and general agitation

A strong colony can defend its entrance. The real risk lies with weak colonies, newly made splits, mating nucs and queenless hives. A weak colony under wasp attack can be wiped out within a few days.

Telling them apart from hornets

If you see a large, dark hornet hovering in front of the hive, photograph it and report it to the official veterinary service / local agriculture authority; the Asian hornet is an invasive species spreading rapidly in Europe.

Protection: step by step

1. Reduce the entrance. This is the single most effective measure. In a weak colony reduce the entrance to a width that one or two bees can pass through; a colony defends a small opening much better. Anti-robbing entrance devices also work.
2. Unite weak colonies. Rather than leaving a colony that would go into winter weak to defend itself, unite it with a strong colony.
3. Leave no smell of sugar in the apiary. Clean up spilled syrup and honey immediately; do not leave extraction leftovers, broken comb, empty supers or leaking feeders in the open.
4. Do not feed in the open. Give syrup inside the hive, preferably in the late afternoon.
5. Keep the hive sound. Cracks, ill-fitting lids and gaps between boxes become second entrances.
6. Keep inspections short. On days of heavy wasp pressure do not leave the hive open for long; the smell of honey triggers robbing.
7. Clean up the surroundings. Rotting fruit near the hives also attracts wasps and hornets.

Traps

Traps are widely used but give limited benefit and are no substitute for reducing the entrance.

• Sugary bait attracts wasps in late summer but also catches honey bees, bumblebees and beneficial insects. If you see honey bees in your trap, change the bait or remove the trap.
• Protein baits such as meat or fish do not attract honey bees; they are more selective in early and midsummer, when wasps are looking for protein.
• Place traps not at the foot of the hives but a little outside the apiary; otherwise you draw wasps towards the hives.

Nests and safety

If there is a nest right next to the apiary that poses a risk to people and animals, leave its removal to a specialist who knows the job. Approaching an underground nest can lead to mass stinging; pouring fuel into the nest or setting it on fire is both dangerous and a fire risk.

The useful side

Throughout the season wasps hunt large numbers of pest insects and have a place in the natural balance. The aim is not to wipe them out but to keep them away from the apiary and keep colonies strong enough to defend themselves.