Stick insect tore about, the clever chap (6,9)
I believe the answer is:
rocket scientist
'the clever chap' is the definition.
(I've seen this before)
'stick insect tore about' is the wordplay.
'about' is an anagram indicator.
'stick'+'insect'+'tore'='stickinsecttore'
'stickinsecttore' is an anagram of 'ROCKET SCIENTIST'.
(Other definitions for rocket scientist that I've seen before include "Clever chap" , "boffin" , "Mastermind" , "I launch farreaching studies" , "A high achiever" .)