The City of Winnipeg will start spraying for forest tent caterpillars on Sunday.

The caterpillars feed on tree leaves and, if left untreated over a period of time, can stress out the trees, leading to disease.

Weather permitting, treatment will start at 9:30 p.m. on May 31 in the Garden City, Margaret Park and Templeton areas using Btk , a biological product.

The city said the infestation will be worst in the northern part of Winnipeg.

"The reason for the area being higher is the previous year the forest tent caterpillars had a high population in the Interlake region. And what they do is they tend to migrate and go to areas of bright light,” said,” Ken Nawolsky; City of Winnipeg insect control superintendent.

The forest tent caterpillar infestation is expected to reach its peak throughout Winnipeg next year before fading away.

The bugs emerge in big numbers every 12 to 15 years.

The last time the city saw a significant infestation was in 2002.

More information from the city is available on its website.