CHESAPEAKE, Va.--(BUSINESS WIRE)--Dollar Tree, Inc. (NASDAQ: DLTR), North America's leading operator of discount variety stores selling everything for $1 or less, will host its conference call for investors and analysts to discuss financial results for the first quarter ended May 2, 2015.   WHEN: Thursday, May 21, 2015 9:00 a.m. Eastern Time   PARTICIPATE: At least 5 minutes prior to the conference call, please dial 888-812-8589 for USA and Canadian calls or 913-981-5519 for international calls