Fighting and Bug types: weaknesses, resistances and Pokémon
Fighting and Bug Pokémon take quadruple damage from Flying moves, take double damage from Fire, Psychic and Fairy moves and resist Grass, Fighting, Ground, Bug and Dark moves.
The balance is even: 4 weaknesses and 5 resistances or immunities.
Fighting moves are super effective against Normal, Ice, Rock, Dark and Steel and not very effective against Poison, Flying, Psychic, Bug and Fairy. Bug moves are super effective against Grass, Psychic and Dark and not very effective against Fire, Fighting, Poison, Flying, Ghost, Steel and Fairy.
To beat these Pokémon, your best pick is Flying moves. Avoid Grass, Fighting, Ground and Bug moves, which deal little or no damage.
There are 4 Pokémon with this combination, such as Heracross, Buzzwole, Pheromosa and Slither Wing.