Entomology is the scientific study of insects. Somebody who practises entomology is called an entomologist.
Entomologists are often found at universities and they are mostly occupied with the study of economically inportant insects, because it is easier to get funding for research into plague species or honey-producing bees or textile producing silkworms than for a harmless little beetle that just chews some dead wood in the forest.
The upside of this is that there is still an awful lot to be discovered about practicallly any insect you care to name that is not 'economically important'. Generally even very basic information, like what it eats exactly, how many eggs it lays, how it finds a mate, and how long do the several stages of development take, is not known.