Insect scientist at last is brought to island (6)
I believe the answer is:
mantis
'insect' is the definition.
(I know that mantis is a type of dictyopterous insect)
'scientist at last is brought to island' is the wordplay.
'at last' says to take the final letters.
'brought to' says to put letters next to each other.
'island' becomes 'man' (the Isle of Man is an example).
The last letter of 'scientist' is 't'.
't'+'is'='tis'
'tis' put after 'man' is 'MANTIS'.
(Other definitions for mantis that I've seen before include "Insect often seen in praying posture" , "It appears to be praying but is more likely preying" , "Predatory insect" , "Insect in attitude of prayer" , "Praying ..., long-bodied, large-eyed insect" .)