Homeowners needn't surrender trees to pine beetle

By Chuck PoulsenSunday, March 18, 2007 http://www.pentictonherald.ca/article_3252.php

Homeowners will have access to three readily available means of defending their trees against pine beetles this year: the pesticide carbaryl, the pheromone Verbenone and fibreglass screening.For the first time, Verbenone pouches will be available in garden and home improvement stores.For those who want to use carbaryl, a Fraser Valley tree service expects to have a team set up in the Okanagan in a month.Tech Mist Spray Solutions will offer several services to homeowners, including the use of carbaryl (also sold under the name Sevin, among other brands). Previously, Okanagan Tree and Lawn Care was thought to be the only company offering the carbaryl treatment here.

Companies expect a huge surge in demand from homeowners because of doomsday predictions for pines in this area. Experts say the western and mountain pine beetles are about to wipe out 75-90 per cent of pines in the Valley’s forests.“Carbaryl is not practical for stands of forests, but it will do the job for homeowners who have trees on their property they want to save,” said Carson Tse of Okanagan Tree and Lawn Care.Leia Toovey of Tech Mist said field tests show that the Okanagan will have pine beetle flights beginning in late May this year.“The winter has been so mild that the larvae are further developed than normal and showing signs of early flight,” she said.Tech Mist and Okanagan Tree and Lawn Care offer integrated measures, which also include the Verbenone pouches and nutrient root injections to keep trees healthier as the bugs invade.Prices for the homeowner depend on the size and number of trees, and on whether it’s best to go with the Verbenone, carbaryl or only nutrients.

However, $50 per tree is a rough average for carbaryl treatment.It can cost as much $1,200 to have a big tree removed, although the average cost would probably be no more than half of that.There are costs beyond that, says Richard Drinnan, a Valley environmental consultant.“The cost of tree replacement, annual tending, loss of shade and noise attenuation, reduced greenhouse gas consumption, increased human health costs from smoke pollution and loss of property values will conservatively add $2,000 to the costs of removing each dead tree,” said Drinnan.The pine beetle problem is “really just starting in the Okanagan,” said Lorraine Maclaughlin of the B.C. Ministry of Forests.“The western pine beetle problem you have here now is just a taste of what you’ll get when the mountain pine beetle starts blowing in huge masses,” she warned.

The Okanagan started to see western pine beetle damage in lodgepole and ponderosa pine stands in 2004 after the Okanagan Mountain Park fire.The mountain pine beetle is a much more voracious bug that has already decimated forests from Prince George to Kamloops. It was spotted in some pines in the Okanagan last year, a sure sign that the Valley is next on its eating binge. Phero Tech of Delta is now setting up accounts with stores in the Okanagan to sell Verbenone pouches.When beetles attack a tree, they put out a pheromone to attract their friends and alert them that a big meal is in store. When they run out of space in a tree, they produce a different pheromone — Verbenone-like — to tell other beetles to stay away.The cost of the Verbenone depends on how many trees need to be treated with the pouches and their distance apart.The pouches will sell for about $17 each.Phero Tech’s Leonard Meltzer said that whether it’s one tree or a stand of trees, protection is needed from four sides.He said tests on healthy trees in the area of the Kelowna fire found that Verbenone is 99.98 per cent effective.However, tests done in East Kelowna and Kamloops last year indicate far less success.Carbaryl spraying can start as early as mid-April this year and continue until the end of June.“It’s pretty effective, if done properly,” said Tse.He said the carbaryl will probably need to be applied annually. However it’s expected the beetle onslaught will be in decline by 2013 as the bugs satiate their appetites with the last of the pines in the Valley forests.

Tse said the Sevin bought in garden stores is a weaker blend of what he is using. The crevices in the bark need to be soaked with the solution, up to two-thirds the height of a tree. That could be 20 metres up on a big tree.“The homeowner probably isn’t going to be able to do that,” said Tse. “It’s not a mist spray. It’s ‘pinned’ like a sheet of glass covering the tree trunk.”He said professional spray units are designed to minimize over-spraying onto surrounding property.Tse says it may not cost any more for a homeowner to have a service such as his do the job than for the handyman to attempt it on his own. The proper process requires a large amount of solution, and contractors are able to buy the chemical at a much lower cost than half-litre bottles sold in a garden store.

The City of Kelowna is using a third method: wrapping the trunks in fibreglass screening that will keep the bugs out. Crews have wrapped 200 ponderosa pines in parks.Even with that, the city’s urban forester is not optimistic.“This is one of our last few options that seem to have hope,” said Ian Wilson. “The outlook is pretty bleak.”Okanagan cities are not using pesticides.The pesticide treatment, although effective and approved by Environment Canada, is controversial. Okanagan cities have been reluctant to use it because of environmental fears and have only recently acknowledged its value in fighting the bugs.

A report from the Entomology Society of America, reviewing 30 years of carbaryl use, finds it effective and relatively safe:“Because carbaryl is much safer than most pesticides, it can be registered at higher concentrations, and because of its low cost, it remains a good choice for control purposes.“There is little likelihood of any adverse effects when applied according to label.”One study the society reviewed from Colorado found carbaryl to be “100 per cent effective in preventing attack.”The literature says carbaryl is effective for two years, but Tse says more recent experience suggests it be done every year, especially if people are watering lawns around the trees and water splashes on the bark.None of this is a science on which all agree.Mark Fercho, environment manager for Prince George, said nothing available assures success.“Unless you protect the tree canopy against waves of beetles dropping from above, there’s no guarantee you can protect them,” he said.