Letter comes two years after Welch led colleagues urging Biden Admin to address illegal deforestation linked to avocados produced in Mexico  WASHINGTON, D.C. — U.S. Senator Peter Welch (D-Vt.), Member of the Senate Agriculture Subcommittee on Conservation, Forestry, Natural Resources, and Biotechnology, today led U.S. Senators Martin Heinrich (D-N.M.), Chris Van Hollen…