I found this little guy, called a Thistle Tortoise Beetle, crawling on some musk thistle that I found on the refuge. Its scientific name is Cassida rubiginosa and it is native to Eurasia. From what I understand, this beetle was introduced to Quebec in 1901 as a control for thistles.
The Thistle Tortoise Beetle has spread throughout North America as far west as Colorado and Alberta and to the East along the Atlantic Coast. It was introduced into New Zealand in 2006. It is sometimes called the Green Tortoise Beetle.