How to distinguish T.sylvestris from T.lineola

It's not that hard, if you know where to look

A lot of people are having difficulties in seperating the Small Skipper (Thymelicus sylvestris, Geelspriet dikkopje) from the Essex Skipper (Thymelicus lineola, Zwartspriet dikkopje). But once you know where to look, it isn't that hard at all! Take a look at the picture at the right. Here you can see the under sides of a Small Skipper (left) and an Essex Skipper (right) cut in half. Notice the following two things:

1. The under side of the tip of the antenna is yellow-orange with the Small Skipper and black with the Essex Skipper. Some people think the antenna of the Essex Skipper must be entirely black. This is not true. Only a black dot on the tip of the antenna is enough to make it an Essex Skipper.

2. Notice the black drawing at the lower edge of the upper wings. With the Small Skipper, this black drawing is constrained to a small area near the base of the wings. The change from black to orange is very abrupt. With the Essex Skipper, the black drawing is broad and fades out to the edges of the wings. In the field the first characteristic is often the only one you need to make a good observation. But, as sometimes happens in a collection, the antenna may be missing. In that case the second one is a 'sure thing'.