Lower Merion's fourth West Nile Virus-positive mosquito trap was discovered July 3, state officials announced Wednesday.

Two others were found June 19 and a third came in June 26, all in Wynnewood or Penn Wynne, according to state records.

The most recent trap to test positive was found at Drayton Lane and Tomkenn Road in Penn Wynne, assistant township manager Pat Ryan said. That is a quarter-mile east of Penn Wynne Elementary School and about the same distance northwest of Penn Wynne Park.

Five positive tests for West Nile Virus were found in Lower Merion all of 2011. The first was not discovered until July 26, 2011, according to state records.

It was not immediately clear whether the latest positive test or the accumulation of four so far would prompt the Montgomery County Health Department to spray chemicals to kill mosquitoes.

However, Ryan said any spraying would be at street level and targeted to areas that have seen positive tests, rather than aerial spraying.

Read on for tips on avoiding West Nile Virus and symptoms and treatment of the virus.

See also:

• Third Case of West Nile Found in Lower Merion (July 10, 2012)
• Symptoms and Treatment of West Nile Virus (June 26, 2012)
• Tips for Avoiding West Nile This Summer (June 25, 2012)
• Second Case of West Nile Found in Wynnewood (June 25, 2012)
• West Nile Virus Found in Wynnewood Mosquitoes (June 22, 2012)