Named tigers because of their black and white stripes, they were initially spotted on Long Island 10 years ago. According to Mary Ellen Laurain, spokeswoman for the Nassau County Department of Health, the Asian tiger was first identified in the county through routine surveillance activities in 2003. In Suffolk, the first showed up in a mosquito trap put out by the county in 2004, Campbell said. They have been moving and have now spread into Brookhaven Town, with a few spotted on the South Fork, he said.