Bug used by US intelligence to catch blighter (6)
I believe the answer is:
cicada
'bug used by us' is the definition.
'cicada' can be an answer for 'bug' (cicada is a type of insect). I'm not sure about the 'used by us' bit.
'intelligence to catch blighter' is the wordplay.
'intelligence' becomes 'CIA' (Central Intelligence Agency).
'to catch' is an insertion indicator.
'blighter' becomes 'cad' (both can mean an unpleasant person).
'cia' placed around 'cad' is 'CICADA'.
Can you help me to learn more?
(Other definitions for cicada that I've seen before include "Flier" , "Chirpy type" , "Loud chirping insect" , "Noisy winged insect" , "jumpy creature" .)