Blooming locusts appearing regularly! (3)
I believe the answer is:
out
'blooming' is the definition.
(I've seen this in other clues)
'locusts appearing regularly' is the wordplay.
'appearing regularly' indicates alternate letters.
The alternating letters of 'locusts' are 'OUT'.
(Other definitions for out that I've seen before include "not acceptable" , "Absent; away" , "At fault - dismissed" , "For example, caught" , "Inaccurate - dismissed" .)