The European Chafer is a voracious and devastating pest that invades lawns. The damage starts when the chafer grubs feed on lawn roots. Later on, the damage intensifies when predatory animals such as raccoons, skunks, and crows tear up lawns looking to feed on these grubs.
Grubs hatch around mid-July and immediately begin feeding on grass roots. By the end of October, these larvae are over one inch in length and are almost unstoppable. They feed for the duration of the winter and then pupate in early spring. The adult beetles emerge in late May, fly to nearby deciduous trees where they mate and subsequently deposit their eggs in nearby lawns where the cycle repeats.
One application of a biological control called Grub Gone is applied in summer. B.t. is the active ingredient in this product and is a live, soil-borne organism, that is released down into the soil and root zone, where the grubs live. B.t. is a natural spore-forming bacterium that occurs in soils everywhere. As the spore matures, it produces a protein crystal that is toxic for insects such as grubs. Once ingested, the insect usually stops feeding within hours and dies within 2 to 5 days.
Health Care Canada has classified B.t. products registered for use in forests, woodlands and residential areas as “restricted”, meaning special permits or licensing is required for purchase. B.t. poses little threat to human health, either through handling products directly, or through indirect exposure such as during a spray program. The fact that B.t. is a naturally-occurring, widely distributed organism in the environment, means that the average person would have multiple exposures to this biological agent throughout their lifetime, even if they never came in contact with a formulated.