Steeves/Trail Mix: Insects having a good year

If you've been on a picnic or to a barbecue, you'll have noticed that this has been a good year for many insects.

Western Yellow Jacket

Western Yellow Jacket

As the first few people began to arrive, so did the uninvited guests.

Striped in black and yellow, they buzzed by ears, landed on skin with a tickle, and searched out every morsel of food and liquid on which to feast.

One guest drank one but spit it out with a grimace and another had to shake one off an appetizer that was headed for the mouth.

It’s a miracle no one was stung, because hornets and wasps can sting viciously, at the slightest provocation.

And, everyone is complaining that this is the worst year they can remember for the nasty picnic and barbecue invaders.

Stores are back-ordered on wasp and hornet traps, lures and insecticide.

Kelowna entomologist Hugh Philip agrees it was a mild winter, which means mortality is reduced for the overwintering queens.

And, an early warm spell this spring could have allowed them to get an early start on production of workers in the hives, which means the hives could be larger than in some years.

He says they won’t begin to establish their nests for the year until there is protein to feed to the developing larva. Sources include May caterpillars, for instance, but if those populations began to build early too, then that could have got wasp populations off to a good start this year.

There’s nothing quite like an outdoor banquet to attract these voracious stingers. While a trap may lure the workers and kill them or trap them, a banquet lures them, but allows them to send out signals or return home to report to the others that there’s a spread waiting for their attendance, and in no time at all, they descend, en masse, to crash the party.

Bees, ants and wasps belong to the order Hymenoptera, many of which sting to some degree or another.

Many ants, bees and wasps have a complex social organization with sterile female workers and fertile males and females.

Despite their tendency to be annoying at summer events, bees and wasps are valuable as pollinators for both food crops, landscape flowers and wild plants.

In fact, Hugh is quick to point out that even the earwig, which people shudder at the thought of, is a beneficial insect which is a predator of leafhoppers, leafrollers, budmoth and even the devastating codling moth pest of apple crops.

He notes that populations of one of the newest imported orchard pests, a tiny vinegar fly called Spotted Wing Drosophila, are 10 times higher this year than in the previous few years that local growers of soft fruit like cherries, peaches, apricots, plums, strawberries, raspberries and blueberries have been fighting it.

It also overwintered well under mild weather conditions and got an early start this season.

There are also more aphids, he points out. A moist spring helped in developing soft new tissue on plants, which is particularly attractive to aphids, and the mild winter permitted the overwintering eggs to survive in good condition.

The lacewings and ladybugs found it impossible to keep up. Usually such predators of aphids have their populations knocked back by this time in the season, but that’s not the case this year, he says.

Other invaders

Hugh advises anyone with the highly-invasive Tree of Heaven or Ailanthus altissima, to watch for the Brown Marmorated Stink Bug, which can cause widespread damage to fruit and vegetable crops and was recently discovered in North America.

While Tree of Heaven is a host tree, this brown, shield-shaped bug invades homes in the fall to overwinter. If you discover it, (photos are available on the internet) you’re asked to report it to the agriculture ministry.

Incidentally, the Tree of Heaven is also an alien invader that can destroy an ecosystem, growing to 80 feet in height in a few short years. It gives off a toxin which prevents the germination and growth of other plants in its vicinity and once cut down, throws out underground suckers that can destroy the foundations of buildings as well as pavement and cement sidewalks.

It has clusters of leaves, similar to a sumac, and it will establish itself in cracks in sidewalks, growing three feet in the first year. It’s currently flowering and going to seed here and produces up to 300,000 seeds a year, in clusters of green, papery, winged structures. Search and destroy it.

Hugh also requests that people visiting the coast of B.C. do not bring back fruit such as apples or crabapples because you could be importing an insect that has the potential to destroy the Okanagan’s orchard industry, the apple maggot.

So many pests and so little time and opportunity to fight them all: you’d better get busy and stay alert to do battle, because new pests seem to invade our province every year.

You’re invited

The Sierra Club B.C. is creating an Okanagan Chapter with its first meeting this Sat., Aug. 10, beginning at 1 p.m., at the Lower Mission Hall. The intent is to protect the area’s native grasslands, forest, rivers and lakes, says Mat Hanson, who says anyone interested is welcome to join and attend the meeting.

Grouse River is holding its grand opening in the new store on Enterprise Way Aug. 23 through 25, with proceeds from raffles to go to Central Okanagan Search and Rescue, Inn from the Cold, B.C. Wildlife Federation, Scouts Canada and CRIS Adaptive Adventures.


Kelowna Capital News