War on gypsy moths begins this week
North Surrey’s Fraser Heights area the focus for aerial spraying of biological insecticide
This week, the B.C. government will conduct aerial spraying over an area of North Surrey in an effort to eradicate the invasive gypsy moth. Here are five things you should know about the gypsy moth and the insecticide spraying operation:
WHAT IS A GYPSY MOTH, AND WHY ERADICATE IT?
Gypsy moths are native to Europe, North Africa and Asia, and the European gypsy moth is well-established in eastern North America. The invasive moths started to appear in B.C. in 1911, but have not yet become established here.
Gypsy moth caterpillars eat the leaves of about 300 varieties of trees and shrubs — including shade trees, ornamentals, and fruit and hazelnut trees — and damage the plants, causing stunted growth, deformities or plant death. A single caterpillar can eat up to 1,000 square centimetres of foliage in their lifetime, the equivalent of about 15 oak leaves.
“If it got here it could be a huge economic problem for horticulture and agriculture,” said Tim Ebata, a forest health officer with the B.C. Ministry of Forests, Lands, Natural Resource Operations and Rural Development, noting that trade with the U.S. could also be affected if the moth population is allowed to grow.
The moths can spread when their eggs are accidentally transported by people, or new caterpillars are blown by the wind.
WHAT INSECTICIDE IS BEING USED?
The ministry uses a biological insecticide called Foray 48B to eradicate gypsy larvae. It is water-based and contains a bacterium called Bacillus thuringiensis variety kurstaki (Btk), which is found naturally in the soil. Foray 48B has been approved for use on certified organic farms, and is not considered toxic or harmful to people, pets or insects such as honeybees, beetles or spiders.
Ebata said some people have reported allergy-like symptoms from exposure to the insecticide, such as runny nose, headache or coughing. Ebata said this can be avoided by staying indoors during and for about a half-hour after spraying.
HOW IS FORAY 48B BEING SPRAYED?
For the past two decades, the ministry has used a small twin-engined aircraft to spray the gypsy moth insecticide. It will likely fly in a north-south direction over the target area, about 100 feet above the treetops.
The insecticides comes out of the aircraft’s spray nozzles in fine droplets, which take between 10 and 30 minutes to land. The droplets stick to hard surfaces — including leaves — where they dry and harden. Caterpillars that eat leaves treated with Foray 48B will die.
The insecticide will wear off surfaces in seven to 10 days — faster, if it rains — or can be washed away with water and scrubbing. If people have items they don’t want sprayed, they should bring them inside or cover them with tarps.
WHEN WILL SPRAYING TAKE PLACE?
Spraying will begin around 6 a.m. on Wednesday — weather and temperature permitting — and Ebata expects it will take about half an hour, although the permit allows spraying until 7:30 a.m.
“It will be over and done with before most people are out of bed,” he said.
Two more applications will take place at seven- to 10-day intervals, and the ministry will give notice when the specific spraying days are chosen. Spraying should be wrapped up by the end of May.
WHAT AREA WILL BE SPRAYED?
The target area is 62 hectares of residential and treed area in the Fraser Heights area in North Surrey, between Highway 1 and Highway 17. There is also a 300-metre buffer zone around the target area, which covers 191 hectares.
Ebata said this area has been treated with ground spraying two years in a row, but the moth persists. He said it is because there is a deep gully behind the Dogwood Campgrounds and RV Park — which they believe is the epicentre — that could not be reached during ground spraying because of poor access.
“If it was flat ground, (ground spraying) would have been quite effective,” Ebata said.
Because of the previous years’ efforts, Ebata said ministry representatives have been able to talk to virtually every affected property owner and resident.
“They’re all on board with the program,” he said.