It might be called Dust and pollen filter

This filter should be replaced every 30,000 miles under normal conditions. It should be replaced every 15,000miles if you drive primarily in urban areas that have high concertrations of soot in the air from industry and diesel-powered vehicles. Replace it more often if air flow from the climate control system becomes less than usual.

以上是從我的維修手冊上抄下來的。