Why Are Wasps and Hornets Attacking My Apples?

In late summer, when colonies are at their largest and the queen has stopped laying eggs, worker wasps no longer need to collect protein for larvae and instead seek sweet, carbohydrate-rich food for themselves. Ripe apples, with their high sugar content and softening skin, become prime wasp targets. A single fruit that is pecked open — by a bird, split by weather, or already fermenting on the tree — attracts wasps that excavate and enlarge the hole, rapidly hollowing out most of the flesh and making the fruit inedible.

Why wasps accelerate the damage

Once wasps begin feeding on a fruit, they deposit pheromones that attract other wasps — a single opened apple can attract dozens of workers within hours. The excavated hole then becomes an entry point for brown rot and other fungi, accelerating the fruit's decay. One wasp-damaged fruit left on the tree can trigger a cascade of damage to nearby fruit as wasps move between them. Remove any fruit that has been opened as soon as you see it.

Wasp traps

Homemade or commercial wasp traps hung in the tree in August capture large numbers of workers but do not eliminate wasp activity — nests can contain thousands of workers and the trap catches only a fraction. Traps are most useful when combined with other measures. Use sweet water, diluted jam, or beer in the trap. Position traps away from areas where people are working in the garden — traps attract wasps from a wide area.

Protecting individual fruit

Paper bags or purpose-made fruit protection bags placed over individual developing apples from July onward prevent both bird and wasp damage to individual fruit. This is practical for high-value or special varieties but not realistic for an entire large tree. Fine mesh bags or organza bags work well for protecting individual fruits.

Harvest at the right time

The most effective and practical approach is to harvest apples at or slightly before their peak ripeness, before wasp pressure in September becomes severe. A slightly under-ripe apple stored correctly will continue to develop flavour in cool storage; an apple hollowed out by wasps is a total loss.