Insects and animals

How to deal with infestation

Bed bugs

bed bug

Bed bugs are a growing problem in large metropolitan areas. According to specialits, the arrival of spring will bring an increase of these insects.

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Cockchafer infestation

If you notice that your lawn has been vandalized by a skunk or yellow patches can be pulled up easily, cut and lift a small section of lawn to confirm the presence of large white worms curled into a "C" shape. The inspection should take place in the spring and in mid-August to mid-September. Have a specialist confirm the extent of the infestation to decide on what action should be taken. Generally, if natural methods are followed, you shouldn't have a problem: Cut the grass to a height of three inches, fertilize, aerate, and water adequately. Use low-impact pesticides (soaps and pyrethrums…) or biological methods (Nematode application procedure). Only use synthetic pesticides as a last resort, once all other methods have been tried; and have your contractor carry out the treatment.

cockchafer larva (white worm)
cockchafer larva (white worm)

Common Adult Cockchafer Beetle

Common Adult Cockchafer Beetle


There is a method to avoid confusing this with the cockchafer - remove the two ends from a coffee tin, plant the cylinder in the ground (at the edge of the yellow patch and about 5-cm deep) and fill it with water. If your lawn is infested with firebugs, you will probably see them float to the surface (immature bugs are either clear red, dark red or brown, adults measure 3.5 mm and are a grey-black colour with black-tipped white wings).

firebug (adult and larva)

Firebug (adult and larva)

Natural methods for controlling firebugs are similar to those used to eradicate cockchafers. However, you should know that firebugs like quick draining, sandy soils.

To control firebugs, use a pyrethrin-based insecticide soap at the beginning of June and before the end of August.

  • Apply in the evening during cloudy weather because these products are photo-degradable
  • Apply after rain – do not water after the product has been applied
  • Treat the area (1 to 2 metres) surrounding the yellow zones and sunny spots
  • Repeat the application once or twice every five days, as required.

Checking for firebugs

Checking for firebugs


Ants are social insects that live in large, organized colonies. Though their predatory ways sometimes earn them a bad reputation, they do a lot of good in the garden and in the lawn; for example, they eat the eggs of the cockchafer beetle. However, it is at the adult stage that they can become a nuisance: carpenter ants can tunnel into decaying tree trunks and into the structural wood in houses.

In the lawn

In lawns, the presence of ants can cause yellow patches on the surface where they have made their nests. Ants often build their nests in lawns that are on sandy soil lacking in organic material.

Because only 5% on ants are outside the nest at any one time, it is better to try to destroy the nest itself. Pour boiling water onto the nest several times to flood all the galleries, or alternatively, pour a solution containing borax at the mouth of the nest (3 cups of water, 1 cup of sugar, and four tablespoonfuls of boric acid). The ants will be attracted to the sugary solution and will carry it back to the queen. Keep the solution out to the reach of children.

In the home

If ants are getting into your house, you should block up any cracks by which they may gain entrance (around the windows or heating system, alongside electrical wiring, around skirting boards, etc…). They can also be carried into the house on logs of firewood. Rooms in the house should also be kept clean - do not leave any water or food within the reach of ants. Store all food safely away in sealed containers to avoid attracting ants.

Low-impact pesticides may be used in your home to control ants (borax, boric acid, diatomaceous earth, etc.). Find the paths that the ants are following and place traps containing borax near the source of the infestation. The ants will be attracted to the bait and will carry it back to the colony.


Spiders are beneficial because they eat insects that are a nuisance such as moths, mosquitoes, and caterpillars that they catch in their webs. Spiders do not transmit diseases. Having a few spiders in the basement will help to eliminate certain insects such as earwigs. Most spiders are nocturnal; they are timid and will hide when disturbed. Spiders may occasionally sting if they are squeezed or if you try to catch them, but such stings are harmless in our part of the world. There are two main groups of spiders:

  • hunting spiders, which actively chase their prey, e.g. water spiders;
  • Spinning spiders, which spin webs and wait for their prey to become entangled in the web, e.g. spiders that are found in basements.

The following prevention and control methods may be used for all spiders.

Prevention and control

In the home:

A clean home discourages undesirable creepy crawlies to come into the house and so reduces the food supply for spiders. To prevent insects from entering the home, block up small cracks and holes around windows, doors, in the foundations, along electric wiring, around steps… and keep the window and door screens in good condition.

Clean into the corners of rooms with a vacuum cleaner to remove crumbs and small scraps of food. Remove old, unoccupied spiders' webs. Clean behind the washer and drier; move furniture around so that spiders do not have a chance to spin their webs. Avoid leaving clothes and covers on the floor - spiders can hide under them during the day. If you see a spider in your house, catch it and release it outdoors.


Turn off outdoor lights at night because they attract insects and the spiders that feed on them. Use yellow light bulbs outdoors to attract fewer insects. If spiders have taken up residence near your home, you can dislodge them with a sweeping brush or a hose pipe. Repeat the process to discourage the spiders and persuade them to go elsewhere.

If you have a serious infestation of spiders, you may use low-impact pesticides. These products are broken down by sunlight and should be used early in the day or in the evening.

"Social" wasps

social wasp
There are different kinds of wasp. Some live in colonies (social) while others are solitary, and they can vary greatly in size. Generally speaking, wasps that live in colonies, often called paper wasps because of their nests, are those which you are most likely to come into contact with. These wasps are very easy to recognize. They measure from 10 to 25 mm long, have a slender, slightly hairy body with a slim waist and are coloured black with markings that are usually yellow but may be white or maroon. Like ants, these wasps form themselves into an organized colony with each individual falling into one of three groups: the queen, the workers, or the males.

In the spring, the fertilized queen leaves the shelter where she has passed the winter to look for a suitable place to build her nest. The queen herself starts building the nest by making a small stem (peduncle) fixed to a solid support. A small dome is then added in which the cells will be built. When there are enough cells, the queen starts to lay one egg in each cell. She cares for the first batch of larvae until they are full grown, which takes approximately twenty days. The workers then take over and carry out all the work necessary for the operation of the nest with the exception of laying the eggs; this is the queen's main task.

The nest reaches its maximum size towards the end of the summer. This is when the workers build the largest cells that will be used to produce the males and future queens. In early autumn, the males mate with the future queens. Only some of these future queens will survive the winter to start a new colony. Depending on the species, the future queens pass the winter under the bark of trees, under dead leaves, in an old tree stump, under a stone, etc. The old queen, the males and the workers will all die in the autumn and the colony will be destroyed. It is important to note that the nest will not be used the following year.

Three types of nest are found in Quebec:

  • The nest shaped like a parasol, suspended from the top by its peduncle. This aerial nest is very robust despite its fragile appearance. It contains between 15 and 200 individuals and is rarely larger than your open hand.
  • The large nests that are to be found in the forest, in agricultural areas, or in towns are the size of basket balls. These nests are built in protected places such as in trees or bushes, under gutters, etc. and can contain up to 5,000 worker wasps.
  • The third type of nest is underground. Wasps take over existing holes such as abandoned rodent nests. The wasps dig out and enlarge the cavity to suite their needs. Sometimes, a small pile of stones can be found at the entrance to the nest.

Generally speaking, wasps' nests only have one entrance. This makes it easier to defend the nest and to control the temperature and humidity. The single entrance is located underneath the nest. Underground nests may have several entrances depending on the size of the colony.

Indirect control

Colonized wasps are always on the lookout for food, potential sources of which must be eliminated. These wasps are most often attracted by sugary food or meat that has been thrown into a garbage bin. Use well fitting covers on all garbage cans and do not leave food lying around outdoors. Moist food for animals is another potential source of food that attracts wasps.

Direct control

Commercially made wasp traps are available, often in the form of a funnel. They generally require some kind of bait (meat, jam…) and can be used to catch a small number of wasps. The inconvenience is that these traps attract wasps, and are not therefore recommended. It is also important to note that DEET or citronella based products provide no protection whatsoever against wasps and bees.

The nest
Eliminating a wasp colony entails some important risks. It is recommended that this work be given to one of the parasite management specialists (exterminators) registered with Ville de Longueuil.

If you have any other questions, please leave a message on the Info-Pesticide line at 450 463-7333.


If you notice that a skunk has moved in under your garden shed or that it causes serious damage to your lawn, here are some tips to help you:

The skunk is a norcturnal mammal that easily adapts to urban conditions. It is unlawful (by provincial law) to hunt skunks. We can only evict them from our properties.

  • We must try not to attract skunks by leaving food outside.
  • Place household trash outside in hermetically-sealed garbage containers.
  • Do not leave piles of construction materials or wood outside. Skunks use it as shelter.
  • If a skunk lives under the garden shed, you must block every possible access with chicken wire except for one so that it may get out. Place mothballs in its den to make it leave. When it's gone, you must block the last access to its den.

It is understood that a skunk that devastates a lawn is only an indication of the presence of cockchafers (white worms). We suggest you read the section on cockchafers to neutralize the problem.