Pest Control

Gophers (Richardson Ground Squirrel):
Gophers are very common in Airdrie and are a very serious threat when they are present on sports fields due to the tripping hazards created. The tolerance level for gophers on sports fields is zero. Sports fields are monitored regularly for gopher activity. Gopher control on the other areas is on a complaint basis.

Treatment Techniques: The City of Airdrie uses the following methods:

Spruce Spider Mite: (Spruce, Juniper, Cedar)

Injurious Stages & Damage: Damage is caused by adult and nymph aphids sucking the plant’s sap. The foliage loses color and eventually dries up and drops. They also spin fine silken webbing, which traps dust particles, dandelion seeds and shed needles, giving the plant a dirty appearance. Discoloration typically is more evident at first in the inner portions of the plant and spreads outwards.
Life History: This spider mite overwinters as tiny red eggs at the base of needles or under loose bud scales. Hatching occurs about mid-May and new adults are found by early June. New generations are produced every two to three weeks during the summer. Populations can build up rapidly if unchecked. Wet weather is detrimental to them.
Cultural Control:Hose down trees and shrubs with a forceful spray of water once a week. Trim the lower branches to increase light and air circulation.
Chemical Control: If infestations persist at damaging levels, apply a foliar spray of chlorpyrifos, diazinon, dicofol, insecticidal soap or malathion. Usually two sprayings are required per season, the first in the third week of May and the second in late June. Use different sprays for each application.

Caterpillars: (Many trees and shrubs)

Injurious Stages & Damage: Several species of caterpillars attack trees and shrubs, chewing holes in leaves or various portions of the leaves. Unless defoliation is severe, overall tree health will not be affected. Common caterpillars are linden loopers, cankerworms, woolly bears and larvae of the pepper and salt moth, rusty tussock moth and tiger swallowtail butterfly.
Life History: Varies depending upon the species of caterpillar. Most overwinter as pupae in the ground and the moths or butterflies emerge in the spring to lay eggs on leaves. Caterpillars grow and feed for two to four weeks (longer for a few). The great majority have only one generation a year.
Cultural Control: Hand-pick and destroy caterpillars.
Biological Control: If necessary, apply a foliar spray of Bacillus thuringiensis.
Chemical Control: Apply a foliar spray of one of the commonly available insecticides labeled for caterpillar control on your tree species.

Aphids: (Most trees and shrubs)

Injurious Stages & Damage: These small, pear-shaped, soft-bodied, variously colored insects are usually found in colonies. They suck sap from leaves, stems or roots causing loss of vigor, wilting, distortion or spots. They also excrete sticky honey dew on which black sooty mold grows. Some curl the leaves and are protected both by the leaf and a waxy coating.
Life History: Aphids overwinter as eggs on a perennial winter host. They hatch in spring and produce one or two generations before generations of living young are produce in rapid succession. In the fall, sexual forms are produced that mate and lay the overwintering eggs.
Cultural Control: Prune off and destroy heavily infested branches. Hose aphids off with water.
Chemical Control: Apply a foliar spray of one of the commonly available insecticides labeled for aphid control on your tree species.

Yellowheaded Spruce Sawfly: (Spruce)

Injurious Stages & Damage: Yellowish green larvae, with yellow or orange heads, consume needles, particularly on open-growing trees. Heavily infested trees appear ragged, especially near the top and take on a yellowish-brown color as defoliation increases. Successive years of heavy defoliation may kill the tree.
Life History: Adult wasplike sawflies emerge from the soil from late May to mid-June. Female sawflies lay eggs at the base of developing spruce needles. Larvae hatch in about a week and feed on the new needles until mid-July. They drop to the ground where they form cocoons in the soil and remain there until spring.
Chemical Control: Apply a foliar spray of malathion, permethrin or soap solution when larvae are small.