European Skipper an Invasive Butterfly

Earlier today I spent most of the morning and early afternoon surveying butterflies as part of the St Paul Audubon's Annual Butterfly Count. The count is held each year at the Arden Hills Army Training Site, more commonly referred to as AHATS.
Since AHATS is a secured military training facility that is under the control of the Minnesota National Guard it takes special permission to get access. This is one of the reasons that I enjoy working on the survey because I get the opportunity to see a little bit of the wildlife that can be found in this large mostly natural expanse. Unfortunately weather hampered this years count and the cloudy skies and wind held down the number of species that we found.
The main butterfly that we saw on the count was the European skipper. This invasive species was accidentally introduced to North America back in 1910 in London, Ontario. Since then it has spread through out much of the continent. It lays its eggs in strings on a larval host plant, mostly grasses, and then overwinters as an egg. In the spring the caterpillars will eat the grasses until maturing and then will pupate. In Europe these butterflies are known as the essex skipper.