The spruce budworm is Canada's number one forest enemy. Found mostly in mature forests in Eastern Canada, it is particularly fond of balsam-fir. Silken hibernation shelters spun in crevices of twigs and bark announce its presence. (Its relative, the western spruce budworm, prefers Douglas fir in Western Canada.) Spruce budworm caterpillars do the most damage in spring: by chewing on new foliage, they cause treetops to turn reddish-brown. The adult budworm is a small brown moth about one centimetre long that appears from late June to early July.
Budworm eggs turn into larvae, which make the silken shelters under bark scales. They overwinter there until the next year, eat the new tree needles, and spin new homes.
Contact your local forestry officials about possible spruce budworm infestations in your area. Offer to check a site for them if it's close by and send your completed Forest Problem Survey Forms to the appropriate people.
Jack-pine Budworm: The jack-pine budworm is a close relative of the spruce budworm, and both insects look similar. In fact, you'll probably need the help of an expert to distinguish between them! The jack-pine budworm is found in the southern range of jack-pines from New Brunswick to Alberta and often feeds on new tree growth.
The male gypsy moth is light brown with fairly large wings, while the female is almost white with black markings on her wings. She's much larger than the male and can't fly. Gypsy moths are found mostly in southern Quebec and Ontario but also in Nova Scotia and New Brunswick. Gypsy moth caterpillars, which have six pairs of red bumps and five pairs of blue ones on their backs, munch on over 500 tree and plant species, including oak, white and grey birch, and tamarack.
To find out if there are gypsy moths in your area, look for egg masses in various locations, including trunks, branches, and bark crevices. To break up these masses, spray them with a sticky cleansing agent (dish detergent will do). Then scrape them off and immerse them in hot water mixed with household ammonia.
Gypsy moth eggs and pupae are often found on objects that may be transported by people. Next time you go camping, hiking, canoeing, or to a cottage, be sure to check your tent, backpack, canoe, or vehicle. Gypsy moths might be hitching a ride with you to new areas!
Mountain Pine Beetle:
Mountain pine beetles just love to munch on lodgepole pine. Found in British Columbia and western Alberta, they also enjoy white pine, limber pine, and other pines. Adult mountain pine beetles are black and stout bodied and measure between four and 7.5 millimetres in length. They bore through the tree's bark and make a place inside to lay their eggs. On the way in, they also infect the tree with a blue stain fungus, which penetrates the inner bark and cuts off the flow of nutrients. The eggs turn into larvae, which continue to feed in the wood until they change into pupae. The pupae then become adults, which eat their way out of the tree and fly on to find new homes.
There are several signs of mountain pine beetle infestations. Piles of boring dust are visible at entrance holes and in bark crevices. A heavy flow of pitch (a sticky, resinous substance) may be seen on the bark of trees that have tried to drown out the beetle. And the foliage of heavily infected trees usually turns red-brown a year later.
The two most common types of tent caterpillars are the forest tent caterpillar and the eastern tent caterpillar. Forest tent caterpillars are easy to spot. They have dark brown bodies with broad bands of blue along each side and a prominent row of white or cream keyhole-shaped spots down the back. They're found on broad-leaved trees across Canada. Forest tent caterpillars like to eat trembling aspen leaves but also munch on balsam-poplar, sugar maple, red ash, mossy-cup oak, white birch in natural stands, and various other trees and shrubs. You might even spot them on poles and fence rails and under eaves of buildings during outbreaks!
In fall and winter, forest tent caterpillars make their presence known by the band of eggs the female lays. The band encircles a twig and is covered with a dark foam-like substance. To get rid of the eggs, you can prune and burn the branchlets that contain them. (Burning should be conducted only by adults.) But if the eggs are on the main stem or on branches that shouldn't be pruned, you can scrape them off with a fingernail or a dull knife. The caterpillars do not form a tent after they hatch, but they do make a silken mat on the trunk or branch where they congregate.
Eastern tent caterpillars (and their close relatives, prairie tent caterpillars and northern tent caterpillars) form silken tents in forks of branches and like to feed on apple and cherry trees and hawthorn shrubs. They have a white or yellow stripe down their backs and are found from the Maritimes to Sault Sainte Marie, Ont., and in the southeastern corner of Manitoba.
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