Insect collects fruit for food (7)
I believe the answer is:
aliment
'food' is the definition.
(aliment is a kind of food)
'insect collects fruit' is the wordplay.
'insect' becomes 'ant' (ant is a kind of insect).
'collects' is an insertion indicator.
'fruit' becomes 'lime' (lime is a kind of fruit).
'ant' placed around 'lime' is 'ALIMENT'.
'for' is the link.
(Other definitions for aliment that I've seen before include "Sustenance" , "Something which nourishes - meal tin (anag)" , "Old word for food" , "Nourishment" .)