It’s early September. This means there are plenty of yellow jacket wasps hanging around your picnic lunches or evening barbecues, right?
Unlike other flying pests, yellow jacket populations are at their peak by the end of the summer. Some healthy colonies can have up to 4,000 workers. And these hordes are hungry: adults feed mostly on nectar, honeydew, and fruit — thus their attraction to sweet smells. (Earlier in the season, the workers were spending their time gathering or scavenging protein, including live or dead insects and carrion, to feed their larval brothers and sisters back at the colony.)
Yellow jackets often build their nests — made from chewed up, saliva-coated wood fibres added layer by layer between spring and fall — out of sight, in hollow logs or stumps or in cavities underground. Most nests don’t grow larger than a basketball, but in hotter climates, where the wasps can build nests year-round, they can get as big as a backyard shed.
Adult yellow jackets only live for about three weeks, and most colonies die by winter. Only the young queens survive, by hibernating.