Scientist into bats suffers breakdown (8)
I believe the answer is:
botanist
'scientist' is the definition.
(I know that botanist is a type of biologist)
'into bats suffers breakdown' is the wordplay.
'suffers breakdown' is an anagram indicator (I've seen this in other clues).
'into'+'bats'='intobats'
'intobats' with letters rearranged gives 'BOTANIST'.
(Other definitions for botanist that I've seen before include "Expert in study of plants and trees" , "Expert in plant biology" , "Plant scientist" , "investigating bloomers, for example?" , "Someone studying plants" .)