REPORTER FILE PHOTO | The town’s inventory of 4-posters ready for deployment in October, 2007 as part of the state-county three-year study of their effectiveness. Rae Lapides, right, was chairman of the town’s Deer & Tick Committee.

Shelter Island can look forward to more 4-posters being deployed next spring, according to Supervisor Jim Dougherty. But permission to deploy five additional units this year came too late to make it practical, he said.

The town deployed 20 units in the third week of May this year, delayed from the optimum March-April deployment by the need to get newly trained pesticide handler Nick Ryan certified. Once the 20 units were in place, the town — which has an inventory of 60 4-posters — had offers from a number of private property owners to deploy units on their land. The town had to await approval from the New York State Department of Environmental Conservation for those additional units.

That approval was late in coming, Mr. Dougherty said in an interview in August.

“The DEC took an extraordinary amount of time to approve this proposed deployment of five additional units,” the supervisor said. “Our consensus, and the private property owners who stood ready to finance concur, that it is too late in the season to deploy effectively,” he said.

“We are going to aggressively plan to deploy more units in 2013, one way or the other, and plan to file very early with the DEC for permission,” Mr. Dougherty said.

He said it was his understanding that the town would have to obtain new DEC permits for next year.

Of the original 20 units deployed at town expense in May, 19 are still in place. One unit at Gardiner’s Bay Country Club had to be removed because it was interfering with the golf course. While the club operators were willing to have it deployed elsewhere on the grounds, the DEC hadn’t given permission to move it in time for this year.

“We are holding our own very well this year regarding keeping ticks down, particularly compared to overwhelmed areas like North Haven,” Mr. Dougherty said.

The devices apply a permithrin solution to the heads and necks of deer as they feed on corn. Deer are the primary hosts for ticks on Shelter Island and the insects concentrate around the ears and necks of the animals.

North Haven was the control site used during the three-year test deployment of 60 4-posters on Shelter Island between 2007 and 2010. Residents of that tiny municipality across the harbor have been petitioning their Village Board to reach an inter-municipal agreement with Shelter Island to lease some of the 4-posters in storage to combat the escalating tick population in that community.

Detractors argue there is no correlation between deployment of 4-posters and any decline in tick-related diseases such as Lyme and babesiosis. But Shelter Island and DEC officials have argued that drag tests conducted in areas where the units are deployed shows a marked decline in the number of ticks that carry the diseases. They point to studies that find it likely that a reduction in the tick population would lead to a decline in tick-borne illness. The opponents argue the $75,000 Shelter Island is spending to deploy 4-posters this year is a waste of money.

The three-year study was funded mostly by the state and county governments. As a result of the study, the DEC for the first time agreed to legalize the use of 4-posters in the state with proper approvals.