European Paper Wasps
In the past few years the Asian Lady Beetle and Asian SoyBean Aphid were major problems here in Ontario. Another introduced insect that we have been encountering and whose numbers seem to be increasing is the European Paper Wasp.
These wasps were first recorded in Massachusetts in 1980. They have been spreading rapidly ever since then. This insect is native to an area stretching from the Mediterranean to China. They are similar in appearance to our regular paper wasps but are slightly smaller and have brighter yellow bands on the abdomen. They prey on caterpillars, feeding them to their larvae in the nests.
Paper wasps are the ones that build upside down umbrella type nests in protected areas such as under eaves, behind shutters, in garden sheds etc. Unlike our native species, the European Paper Wasps will build their nests just about anywhere including the exposed sides of homes, along fences, in bird houses, gas vents and innumerable other often strange locations. They also seem to be more prolific and will build up large populations in a short time. Last summer, we found anywhere from 2 to 3 nests up to 40 or 50 nests on some larger homes. Overwintering queens may stay in the nest all winter and use them again the following season. These wasps can be quite aggressive and have the habit of buzzing you if you start to get close to the nest. They will sting if threatened or provoked.
Control involves treating individual nests and removing them if possible. If the wasps are going into the soffit and facia areas, these areas have to be treated. Nests are often built on the sunny sides of a house. People with allergies to bee and wasp stings should use caution around the nests of these wasps.