A tick found in South American island state (5)
I believe the answer is:
samoa
'island state' is the definition.
'a tick found in south american' is the wordplay.
'tick' becomes 'mo' (both can mean a very short amount of time).
'found in' indicates putting letters inside.
'south american' becomes 'SA'.
'a'+'mo'='amo'
'amo' going inside 'sa' is 'SAMOA'.
(Other definitions for samoa that I've seen before include "South Pacific island nation" , "Polynesian isle" , "Commonwealth country in the Pacific, capital Apia" , "Group of volcanic islands in the S Pacific" , "island territory" .)