The Male Beetle is one of the 24 Golden Bugs in Twilight Princess. Its female counterpart is the Female Beetle. This bug can be traded to Agitha for a Rupee prize.
The Male Beetle is located in the part of Hyrule Field north of Faron Woods. The Female Beetle is also located around here.
Male Beetle's location in Hyrule Field
Male and Female Beetle's locations on the map