Wasps

If you have been stung in the past few years the odds are you were stung by a wasp. Largely considered "pests", there are many different species of wasps but the most commonly known is the yellow jacket. This post will cover identification and life cycle information.



Name: Common Wasp - Vesupla vulgaris
Size: 1.2 - 1.7cm
Colour: Yellow and Black
Nesting Sites: Old mammal burrows, tree hollows, man made hollows.
Nesting Material: Chewed wood fibers, often grey in colour
Colony Size: 5,000-10,000
Food: Insects, nectar, fruit
Stinger: Smooth, 15 stings per minute

Much like Bumblebees, the yellow jacket queen will hibernate through winter in a protective spot that she previously found in fall. Come spring she will go about starting a small nest, laying eggs, and feeding her first brood. She does this alone and it is not uncommon for early nests to fail, however once the first workers hatch, in 28-34 days, she then focuses her efforts on laying eggs and the colony soon becomes strong. In fall new queens and male drones will start hatching. The queens will stay in the nest to build up fat stores for winter and the males will stay as long as they are allowed to. The males will at some point be forced out of the nest and will then forage for themselves until they find a queen to mate with. Before winter the new queens will leave the nest and find a spot to hibernate, the colony will die off when the weather becomes cold. Normally a nest will only last 1 season, but in warmer climates they have been known to survive and grow into large nests with multiple queens laying. Old nests are not reused by new queens.

Yellow jackets are primarily seen as pests because of their feeding habits. Most BBQs and picnics offer an excellent source of food as they will gladly help themselves to meat and sweet syrups. This is where a majority of stinging incidents happen. Wasps do not usually stray further than 1000 meters from their nesting sites.

While not always aggressive, if trapped or pinched a yellow jacket will sting usually because they have landed on a human food source unnoticed. Wasps will also defend their nests vigorously and with their ability to sting multiple times can cause serious injury. Wasps will secrete a defense pheromone as well as beat their wings in a different frequency to alert the nest causing a massed defense.


Also common in Canada is the bald-faced hornet, Dolichovespula maculata. While not technically a hornet, hornets are usually defined by their hanging nests, they are wasps and can be easily identified by their white and black colouring. They build their paper nests hanging in trees or on sheltered structures and have a life cycle like that of the yellow jacket.