Noisy beasts, 101 reprobates, Australian being hugged (7)
I believe the answer is:
'noisy beasts' is the definition.
'101 reprobates australian being hugged' is the wordplay.
'101' becomes 'CI' (roman numerals).
'reprobates' becomes 'cads' (I've seen this in another clue).
'australian' becomes 'A' (common abbreviation).
'being hugged' indicates putting letters inside.
'cads' going around 'a' is 'cadas'.
(Other definitions for cicadas that I've seen before include "These insects have an acid sac" , "Noisy insects" .)