My how this field guide has changed over the years. The edition on the left is one of the first versions and it is undated. The one on the right is the most recent. It is from 2002. It is going to replace the one that was borrowed and never brought back to the growers library that I help to curate. Whenever I can find newer editions I snag them. This is a popular book that often get borrowed to infinity. It means that it is being used. 🦋🐛