Stinging Insects

by Daniel J. Fiorini, CET, Project Coordinator, CSAO

 

Two years ago a construction worker died when he fell from a ladder after being attacked by bees. A few tips about stinging insects can help to prevent injury.

Nesting

Yellowjackets make their nests in the ground, old tree stumps, frame walls, and cracks in masonry. Wasps nest in trees and bushes, under houses and eaves, behind shutters, and in lumber, material, and woodpiles. Hornets construct a gray or brown paper football-shaped nest in trees, shrubs, and gables, usually five to ten feet above the ground. Bumblebees build nests around debris, often starting with an old mouse nest. Honeybee hives may be found in the hollow trunks of trees, suspended from branches, or even between the outside walls of buildings. They are non-aggressive and will usually sting only when provoked.

Behaviour

Stinging insects are most active during summer and early fall when nest populations can exceed 60,000. The insects are most dangerous near their nests where you will be seen as a threat. Stinging insects are attracted to dark colours and floral prints (wear white or light-coloured clothing). Scents in everyday products such as deodorant attract stinging insects whereas sweat seems to irritate them.

Precautions

• Forget about insect repellents. Insect repellents DO NOT work against stinging insects.
• Never swat or swing at stinging insects. They’re more likely to attack a moving than stationary object. Rapid motion often provokes an attack. Wait for the insect to leave, softly blow it away, or gently brush it aside.
• Run only if a nest of bees, wasps, hornets, or yellowjackets has been disturbed. Head indoors if possible. Otherwise run through a tree-shaded area (stinging insects prefer open spaces). If there’s a body of water nearby, jump in as a last resort.
• Do not crush a wasp that stings you. Crushing releases an airborne chemical signalling other wasps to attack.
• A honeybee will leave its stinger in your skin. Remove the stinger by pushing or scraping (not pulling) it out.
• A person who reacts to a sting by swelling or shortness of breath should be taken to a doctor or hospital immediately.

Eliminating Nests and Hives

• The first step is to locate all the entrances to the colony.
• The next step is to wait until two hours after dark when all the worker insects will be in the colony and inactive. Carefully approach the colony and thoroughly spray the entrances using wasp and hornet spray for visible nests or insecticide dust for nests in earth or structures. Block the entrance to a ground colony after treating.
• Don’t burn or flood nests. This doesn’t kill all the insects and the survivors will be annoyed.
• Inspect work areas, especially in spring and summer, for any new nests. If nests pose a danger to workers, treat as noted above and monitor for 24 hours. If insects are still present, ensure that all entrances have been located and then repeat the treatment.