Hi Audrey, I've not come across many, but I know of two that may or may not be useful.
1. The Florida Medical Entomology lab offers a 2 week intense course for mosquito identification (both adults and larvae). It's $500 and you have to stay near the site during the course (so factor in those costs). 2. There is an ant ID course that is offered via the California Academy of Sciences (https://www.calacademy.org/scientists/ant-course). It's often international. Note that a lot of entomologist are self taught and come to their skills via practice and assistant from their mentors or other experts in the field. If you are in an entomology program you often get access to courses as well. I myself learned all my ID skills from text and practice. Hope that helps. Don...
