You may notice some folks with binoculars looking up into trees in pockets of the city this week.
BioForest Technologies is conducting a gypsy moth egg mass survey from Monday to Friday.
Sarnia Forestry Supervisor Chuck Toth said the survey will consist of 20 plots.
"They go out to designated areas and do a visual search and count, and from that information, they'll draw up some general guidelines that will determine the density of the gypsy moth in certain areas," said Toth.
2,500 egg masses per hectare is the threshold for recommended treatment.
"The egg masses are easy to spot. There's a white to yellowish mass on the inner side of the lower limbs generally on the trees. So, if you're walking just look up on the inner side of the branches and see white to yellow patches, that is the egg mass itself," said Toth.
15 plots are to be surveyed West of Indian Road and North of Rosedale Avenue.
Canatara Park, Oak Acres Park, Woodland Park, cemeteries and neighbouring streets will be surveyed.
Sample plots will also be surveyed at Sylvan Park, Clarence Park, Wildwood Park, Camp Saredaca and Cardiff Park.
Sarnia council approved spending up to $90,000 to control gypsy moths in the 2020 budget.