I receive lots of emails from extension agents, growers, and homeowners requesting insect identification. Oftentimes, these emails are accompanied by photographs of the insect, associated damage, or both. Sometimes, these images are useful in determining what species, or more commonly, what general group of insects are responsible for the damage. Most of the time, however, these images do not aid in insect identification and can even make it more difficult.
A group of entomologists from throughout the southeastern US have developed a series of training modules on basic insect identification, including Wiki pages, targeted to master gardeners, homeowners, and invasive species first detectors. The First Detector Wiki describes how to identify some of the most common pest species as well as some of the most important invasive species spreading throughout the US.
More importantly for the budding entomological photographer, there are pages which cover the basis of how to properly photograph and submit images for digital diagnosis and how to collect and preserve insect samples for diagnosis.
The First Detector Wiki also includes information about some of the many pests in several insects orders. Each of these order-level pages also includes information on how to take a good picture of members of that group. For example, information to on taking a diagnostic photo of Dipterans (flies) is here. The Diptera and Coleoptera (beetle) pages were developed by recent NC State Entomology graduate Matt Bertone in collaboration with myself and Mark Abney.
If you are interested in photographing insects for reasons beyond simple diagnosis, there are lots of amazing sites devoted to insect photography. Some of my favorites are from Alex Wild (here and here) and Piotr Naskrecki (here).
How to properly photograph and submit images for digital diagnosis - First Detector Wiki
Collecting insects - First Detector Wiki