The most common and most likely answer to this crossword clue is the 5 letter word NOTUM
I've seen this crossword clue in Independent
N
O
T
U
M
More clues leading to the result NOTUM
Buddy explains!
The straight part
We know that "Part of an insect" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of an insect = notum.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does NOTUM mean?
NOTUM noun- The back; the dorsal aspect of the thorax in insects.