European paper wasp

Systematic position: The European paper wasp (Polistes dominulus) belongs to the order Hymenoptera and the family Vespidae. This social insect is known for constructing open, umbrella-shaped nests from a paper-like material made of chewed wood fibers. They are highly adaptable and often thrive in proximity to agricultural fields and orchards.

Biology and life cycle: The life cycle begins in spring when a solitary overwintering queen starts building a new nest. Throughout the summer, the colony grows as the workers forage for protein for the larvae and carbohydrates for themselves. The population peaks in late summer, and by autumn, the colony produces new queens that seek shelter for the winter while the rest of the colony dies off.

Damage and harmfulness: While wasps prey on some garden insects, their impact on fruit crops is negative. They chew through the skin of ripening fruits and berries to feed on the sugary juices inside. This not only destroys the fruit directly but also creates entry points for fungal infections and rot, often drawing in other pests like vinegar flies.

Affected crops: The primary targets for paper wasps are soft-skinned fruits such as grapes, strawberries, raspberries, peaches, and plums. Vineyards are particularly vulnerable during the harvest season when the high sugar content of the grapes attracts large numbers of foraging workers.

Control measures: Successful management requires a combination of strategies:

• Locating and removing nests early in the season, preferably at night.
• Using bait traps filled with sugary liquids or vinegar solutions to reduce adult numbers.
• Protecting fruit clusters with netting or bags to physically exclude wasps.
• Maintaining field hygiene by promptly removing fallen or damaged fruit that could serve as a food source.