Yellowjacket or hornet (4)
I believe the answer is:
wasp
I believe this clue is a double definition.
'yellowjacket' is the first definition.
(I know that yellowjacket can be written as Wasp)
'hornet' is the second definition.
(I've seen this in another clue)
(Other definitions for wasp that I've seen before include "spiteful person?" , "Social worker" , "Striped insect" , "Insect often irritating in summer" , "Buzzer" .)