Adult beetles emerge between late May and August through round flight holes between 1/16 and 1/8 of an inch (1-2mm) in diameter.
Mae chwilod llawndwf yn ymddangos rhwng diwedd mis Mai a mis Awst drwy dyllau hedfan crwn rhwng 1/16 ac 1/8 modfedd (1-2mm) ar eu traws.