Integrated Pest Management

There are numerous pests that consider Yorkton home. Each pest requires different tactics to keep them under control. The City implements many programs on a regular basis, however there are some strategies that you and other residents can implement on your own property to help.

Tree worms

Tree worms are a common pest with the City of Yorkton. There are two distinct species of tree worms that are common in the city:

  • Forest Tent Caterpillar and;
  • Cankerworm.

Both species cause similar unsightly and unhealthy effects on trees and can be controlled in the same manner.

Forest Tent Caterpillar adults are tan colored moths, with two thin dark, parallel oblique lines of one single, broad, dark band crossing the middle of the front wings. The mature larvae are 45 to 55 mm long and are bluish to brownish in colour with diamond-shaped white spots on the middle of the back of each segment. It has two thin prominent broken yellow lines that extend along each side of its hairy body.

Both spring and fall cankerworms are about 2.5 cm long when fully grown. They range in colour from light green to brownish green with a dark stripe down the back.

Symptoms and characteristics

Forest tent caterpillar larvae feed initially on the opening buds, later consuming parts of or whole leaves of broad-leaved deciduous trees and shrubs. During high population, forest tent caterpillars can completely strip trees and will then feed on the shrubs and other vegetation.

Cankerworms leave small holes in the new leaves. As the cankerworm larvae eats, the hole become larger until only the leaf veins remain. During high populations, canker worms can also completely strip trees of their leaves.

Will the tree be damaged?

Healthy trees should grow back their leaves two to three weeks after being stripped or by early July depending on the year. However, their growth is slower and they are less able to fight potential new diseases and other insect attacks.

Control and preventions

On smaller trees and shrubs, an effective means of controlling the forest tent caterpillar is pruning or breaking off the egg masses on the twigs and disposing of them in the garbage. This is best done in fall or in early spring when there are no leaves on the trees and the egg masses are most visible. After hatching, young colonies of larvae can be pruned off or squashed while they are resting in clusters on the main stem, especially in the evenings or on cool nights.

The best way you can control adult cankerworms is to band your trees. Banding your trees with a product, such as Tanglefoot, is an environmentally acceptable way to keep adult cankerworms from climbing the tree to lay eggs. You should band your trees by mid-March to control the spring cankerworms and by mid-September (or before the first hard frost) to control the fall cankerworm. Encourage your neighbours to also band their trees because cankerworms can travel on their silken threads as larvae. Remember to remove the band by the end of June to prevent rotting bark.

When trees are too large or there are numerous larvae of either worm species, a non-chemical insecticide that contains Bacillus thuringiensis var, kurstaki (BTK) such as Bioprotec ECO and Safer's BTK Biological Larvicide are good environmentally friendly ways to control tree worms. Chemical agents can also be sprayed to control worms. Remember to always follow the manufacturer's label when using chemicals. All pest control product purchases and uses must be registered with Health Canada and contain a Pest Control Product (P.C.P. or PCP) number or label.

What is the City doing?

The City of Yorkton has a tree worm control program in place. At the first sighting of tree worms, the Parks division begins preparations for spraying City owned trees. Initial spraying we use a product called Dipel, which contain BTK. This product must be ingested by the worm and is sprayed onto the leaves when the worms are feeding. During heavy infestations, a second spraying of a chemical insecticide called Pounce may be used, which begins working on contact with the worm.

Tree Banding

Tree banding keeps fall and spring cankerworms from laying their eggs in the crown of the tree. Band your elms, Manitoba Maples and fruit trees each spring and fall to reduce the amount of cankerworms.

To band your trees:

  • Purchase fibreglass insulation - 15 to 20 cm wide, plastic wrap or black garbage bags, duct tape and some type of sticky substance;
  • Wrap a strip of fibreglass insulation around the trunk and one to two metres above the ground;
  • Cover the insulation with plastic and secure with duct tape;
  • Cover the plastic with your sticking agent;
  • Regularly re-apply your sticking agent and remove debris to ensure effectiveness;
  • Remove your band after mid-May and again in mid-November to keep your tree bark in good shape;
  • Save the insulation for the next banding season.


The Culex Tarsalis species of mosquito is known to be the highest potential risk of transmitting the West Nile virus. The Culex Tarsalis seems to be most active in the mid to late summer months; however, protection should be on-going.

Female mosquitoes bite for a blood meal which allows them to lay eggs. Eggs may stay dormant for years. When there is sufficient water the eggs will hatch, continuing the cycle of mosquitoes. Large bodies of water such as Yorkton's Jaycee Beach and the Ravine Ecological Preserve do not have a lot of mosquitoes as the water is too deep. Eggs are laid in shallow areas of standing water.


To monitor and track adult populations, the City along with Saskatchewan Public Health have light traps set up in two locations of the City to count and forecast trends for future management strategies.


Skunks are known to be carriers of rabies and other diseases. If there is a skunk on the home owners' property, it is their responsibility to dispose of it. The main reason a skunk will come around onto your property is because it is looking for food and shelter.

How to get rid of skunks

Remove all food sources

Skunks are scavengers. They will eat anything they can get, including bird eggs, small rodents, bugs, larvae and garbage. If you have pets, do not leave their food dishes outdoors. If you have fruit trees or bushes on your property, be sure to clean up any fruit that happens to drop on the ground. Rodents enjoy this food source and skunks enjoy the fruit and the rodents. Be sure to cover your compost to keep pests out.

Try out skunk repellants

Since skunks are nocturnal, this means they do not like bright lights. Try using a motion sensor in your yard that will turn on a light when movement is sensed. Skunks also do not like getting soaked with water, automatic sprinklers can help. You can also find several designed skunk repellants, i.e., a spicy pepper solution. Spray them on trees and other areas where you have seen skunks.

Put up some skunk barriers

If you have a skunk living on your property, try and seal off areas that they get into. The best strategy is to put up some barriers around areas that skunks find interesting to help keep them away. Keep in mind that skunks cannot jump so these barriers do not need to be very high. Skunks are very good diggers and they can fit through openings roughly four inches in diameter.

Use a skunk trap

If you have tried everything else, you may need to trap the skunk. When buying a trap, make sure it is small enough that any skunk you capture cannot raise its tail inside the trap.

Gophers and Moles

The City of Yorkton controls gophers on City property. In the early spring gophers are baited with a product called Rozol or smoke bombs that are placed down the gopher holes.

For moles, mole traps are used and checked by staff daily.

Nuisance birds

The City of Yorkton does not have a program for nuisance birds but here are some helpful tips that can help deter them:

  • Birds are driven by the need for food. Use inexpensive landscape netting or any type of lightweight net to cover trees and plants. Landscape netting allows ample sunlight for your plants while protecting them from the ravenous birds. The birds will soon realize there is a barrier between them and their target. Once they realize they cannot access the food, the birds will move on in search of other more accessible hunting grounds.
  • Try deterrents such as plastic owls or hawks, rubber snakes, spinning Mylar whirligigs or wind chimes. These scare tactics can often make the birds move on. You can also find sonic emitters, electronic devices that let out high pitched sound, designed to drive birds away.

Some other deterrents that can be used are:

  • Spray the nuisance bird with water from a garden hose
  • Knock down or dissemble nests out of trees
  • Install plastic or metal spikes on ledges, window sills or roof peaks
  • Consider a chemical bird repellent if pigeons are already a nuisance
  • Place chicken wire around areas, such as small attic windows, where pigeons are prone
  • Use a transparent bird gel on branches and other roosting areas. Bird gel is a non-toxic sticky substance that makes the surface uncomfortable for the birds.
  • For crows shine a laser beam at them. This will disturb them from their roosts temporarily but after continuous harassment, crows will avoid the area
  • Hang a fake crow upside down with its wings spread out. Crows will avoid the fake dead crow.
  • Use loud sounds to frighten crows away. Play a recorded audio of crow predators or crow distress calls.
  • Scare crows away with reflective objects around your property. You can find bird tape that is designed as a visual deterrent to crows. Hang shiny streamers on poles throughout your yard or old cd's. Move them to different locations periodically to keep the crows from overcoming them as a threat.