Canadian lawns suffer from many of the same diseases, insects, and pests as lawns throughout the world. Insects, in particular, can severely weaken and damage a Canadian lawn and leave it vulnerable to die-off in the cold winter. There are four insects that perpetrate the most damage to lawns in Canada at varying times of the year. Some destroy the roots of the grass, some eat the grass itself and some will suck the sap from the grass blades.
Chinch bugs can quickly turn into a major infestation on lawns that are not dethatched or cared for on an ongoing basis. Chinch bugs cause large yellow patches of dead and dying grass. Adult chinch bugs suck the sap out of grass blades, leaving them vulnerable to winter kill or to dehydration in the summer heat. Larvae chew off the grass blades at the soil level. Chinch bugs overwinter well, so if an active infestation is not dealt with, it can spread even farther the following season. There are both chemical insecticides and organic preventative measures to deal with chinch bugs. Proper lawn maintenance also reduces the likelihood of the bugs moving into your lawn.
Beetle grubs are the larvae of several different beetle species. The adult beetles lay their eggs in compacted lawn soil and the larvae feast on the roots of the grass, severing them from the plant. Grubs cause yellow patches in lawns but are most often detected before widespread infestation by the presence of holes in the lawn. The holes are most often caused by skunks who love to dig for the grubs. Positively identify beetle grubs by digging up a small area of lawn and looking for the thick white larvae curled up in the soil. Aerating the soil at least annually helps to control grubs, and there are several organic methods of ridding your lawn of these destructive pests.
The larvae of the click beetle are known as wireworms, and these insects can be found in flower and vegetable gardens as well as lawns. In fact, wireworms often spread from infested gardens into the lawn. Wireworms cause damage much like grubs and eat the roots of grass at the soil level, killing the plant. They are longer and more slender than grubs. The treatment for wireworms is the same as for grubs. Proper aeration and lawn maintenance also reduces the likelihood of an infestation.
Webworms are the caterpillar stage of the sod webworm moth. These small white moths lay eggs in lawns throughout the spring and summer. The larvae feast on grass stems at the soil level and can cause large yellow patches in the lawn throughout the season. The moths most often are active at night, and you can spot them flying around the lawn in the late evening or early morning. The larvae are only active at night and hide during the day. Webworms love lawns with a thick thatch, so proper lawncare is the key to avoiding an infestation. Treatment of an existing infestation is straightforward with several organic treatments including Bacillus thuringiensis, a soil-dwelling bacterium.