Mr. Chan , 29 , said that workers at the packing house in Korla use air guns to clean the pears of insects and debris , check them with magnifying glasses , and then cushion them in tissue paper and foam mesh sleeves for the journey ahead : seven days by truck , over small roads as well as highways , to Shenzhen , a port near Hong Kong ; two weeks by container ship to Long Beach , Calif. ; and another five days by truck to New York .