Insect food (4)
I believe the answer is:
grub
I believe this clue is a double definition.
'insect' is the first definition.
(a grub is an insect larva)
'food' is the second definition.
(grub is a kind of food)
(Other definitions for grub that I've seen before include "Nosh - larva" , "Larva; dig shallowly" , "ferret > eats" , "Dig (up); hack writers' Street" , "Insect larva or slang food (4)" .)