Chap does away with companion over veiled threat in bed (5)
I believe the answer is:
aphid
'threat in bed' is the definition.
(aphids may threaten plants in a flower bed)
'chap does away with companion over veiled' is the wordplay.
'does away with' suggests deleting specific letters (to do away with can mean to remove).
'companion' becomes 'ch' (Companion of Honour).
'over veiled' becomes 'hid' (I've seen this in another clue. I am not sure about the 'over' bit.).
'chap' with 'ch' removed is 'ap'.
'ap'+'hid'='APHID'
(Other definitions for aphid that I've seen before include "Insect feeding on plant juices" , "insect pest" , "Sap-sucking bug" , "plant pest" , "little sucker" .)