Louse's elevated state kept under wraps (5)
I believe the answer is:
aphid
'louse's' is the definition.
(aphid is a kind of louse)
'elevated state kept under wraps' is the wordplay.
'elevated' says the letters should be written in reverse (down clues only).
'state' becomes 'pa'.
'kept under wraps' becomes 'hid'.
'pa' written backwards gives 'ap'.
'ap'+'hid'='APHID'
(Other definitions for aphid that I've seen before include "Fly" , "Sap-sucking bug" , "Small plant-sucking insect" , "Garden pest" , "Garden bug" .)