Beatles get disturbed by an insect (4,6)
I believe the answer is:
stag beetle
'an insect' is the definition.
(stag beetle is a kind of insect)
'beatles get disturbed' is the wordplay.
'disturbed' indicates an anagram (the order of letters is disturbed).
'beatles'+'get'='beatlesget'
'beatlesget' anagrammed gives 'STAG-BEETLE'.
'by' acts as a link.
(Other definitions for stag beetle that I've seen before include "Horny little creature" , "Large insect with branched mandibles" , "something some folk find creepy" , "Insect with antler-like jaws" , "Six-footer" .)