"Police and environmental inspectors have already closed down 17 sawmills to protect forests in Michoacan state, where the butterflies spend the winter. They have also confiscated more than 300 truckloads of wood from illegally felled trees and arrested 28 people.
The Monarch butterflies migrate south from the US and Canada every autumn to escape the cold north American weather. The sight attracts some 200,000 tourists every year who flock to the area in butterfly-watching season.
However, butterfly experts have warned that the long-standing problem of illegal tree-cutting in Mexico could end the Monarchs' annual journey if it is not stopped.
EDIT
Mexico's top environmental prosecutor, Jose Luis Luege Tamargo, said illegal loggers faced jail sentences of three to five years. However, prosecutors admitted that they were finding it difficult to combat the demand for illegally-harvested wood in the construction and furniture industries."
EDIT
http://news.bbc.co.uk/2/hi/americas/3283761.stm