PONTIAC (WWJ) - An Oakland County park remains closed for the third week as officials continue work on eliminating an infestation of wasps that have taken up residence on the grounds.
Optimist Park, located at 162 W. Fairmount Ave. in Pontiac, is still off limits to visitors, although some improvement has been made on eradicating the pesky invaders.
Mayor Tim Greimel says he's "never seen anything quite like this," not just during his time as mayor, but in his entire life.
"Pest control recently reported an 85% reduction in wasp activity and applied a second treatment to the park," officials said in a update on the situation this week.
Experts are due to come back and evaluate wasp activity. Officials said it remains unclear when the park will reopen pending a green light from the pest control company.
Officials were forced to immediately close the park back on August 11 over safety hazards due to the "extremely aggressive" ground hornets.
A number of signs, as well as caution tape, were put up to warn guests.
"Please DO NOT visit this park until we are able to eradicate the hornets nests for everyone's safety!" the city wrote.
According to Howard Russell, MSU Diagnostic Services, Department of Plant, Soil and Microbial Sciences, getting rid of wasps is "tricky business."
"As many of us know, the occupants of these nests tend to resist any effort to kill them by stinging the daylights out of those attempting to do so," Russell wrote of the insects.
In Michigan, yellow jackets, bald-faced hornets and paper wasps construct nests in the ground, in trees, under eves and inside wall voids and attics in late spring and throughout summer.
August is a particularly active month for colonies as they reach their maximum size of worker wasps, with yellow jackets known to swell to numbers between one or two thousand.
"The last brood raised includes males and next year’s queens. Due to the importance of these reproductives, the worker wasps become very protective and aggressive toward those who venture too close to the nest this time of year," Russell explained.
MSU Extension recommended pest control professionals take care of large nests of yellow jackets and bald-faced hornets.