What's in a name?

I went to a meadow event in Silverdale where there were enthusiasts for both flowers and insects. A moth trap had been set up overnight and an expert was on hand to name them. Here is a Heart and Dart Moth (Agostis exclamationis), and the extra shows a Footman, so named because they tend to 'stand up tall and straight' (but it's also more colourful than the closely related Dingy Footman).