A little epitaph is written for the pest (5)
I believe the answer is:
aphis
'pest' is the definition.
(I've seen this before)
'a little epitaph is written' is the wordplay.
'a little' indicates the answer is hidden within the clue.
'APHIS' is hidden in the letters of 'epitaph is written'.
'for the' acts as a link.
(Other definitions for aphis that I've seen before include "Sap-sucking garden pest" , "Plant louse" , "Small insect" , "Greenfly" , "sucker?" .)