Since a dragonfly is an insect, the field of study is called Entomology so the people who are studying insects are called Entomologists but there are also some specific terms that are used for the people who study dragonflies.
meteoroligists
=A Microbiologist studies microscopic organisms.=
A scientist is someone who studies science.
A scientist who studies anatomy is called a anatomist.
A scientist that studies bears would be called an ursinologist.
A mineralogist studies minerals.
An ecologist studies pollution
The kind of scientist who studies Urology would be a Biologist, since Urology concerns a biological function (urination). If you mean the kind of doctor who studies Urology, that would be a Urologist.
meteoroligists
Audiologist
An Ichthyologist.
Botanist
cosmologists
seismologist
a biologist
Mathmaticion
A zoologist.