Insect hidden in ordinary kind of banana (8)
I believe the answer is:
plantain
'kind of banana' is the definition.
'insect hidden in ordinary' is the wordplay.
'insect' becomes 'ant' (ant is a kind of insect).
'hidden in' is an insertion indicator.
'ordinary' becomes 'plain' (I've seen this before).
'ant' inserted inside 'plain' is 'PLANTAIN'.
(Other definitions for plantain that I've seen before include "Pal at inn (anag)" , "Sort of banana" , "Large banana - weed" , "Low-growing plant; type of banana" , "Coarse banana" .)