A plan to spray vegetation at the South Hill Mall in Puyallup with insecticide to treat for gypsy moths has been approved, and the spraying will start late this month or in May.

There will be three to five treatments of the biological insecticide known as Btk at the 29-acre site, the state Department of Agriculture said.

The date of the first treatment hasn’t yet been determined and will depend on larval and leaf development and weather, the agency said in a news release.

The treatments will be about a week apart and will be done at night.

There are no homes in the area to be treated, which is at the northwest corner of the mall parking lot, the release said. State entomologists found an infestation there last summer.

The agriculture department proposed the treatment plan late last year. It was approved last week after the public had time to offer comments on a pair of documents assessing the environmental impact.

None were received, the news release said.

For details on the treatment, call 1-800-443-6684 or click here.