Termite anatomy is studied by entomologists mainly because it is an essential key in identifying termite species. The soldier is the main caste that is referred to when differentiating between species because most of the time, in closely related species, the workers and the imagos (reproductives) are highly similar.
Effective termite species identification involves scrutinizing soldiers under a microscope and looking for any minor differences in their anatomy or morphology. I believe inbreeding between closely related species may be the reason why some localized subspecies that are very hard to tell apart.
There have been quite a number of reclassifications of certain species over the years; evidence of the problems involved in accurate termite species identification.
Some common parts of soldier caste morphology used in termite species identification are shown below.