Because insects eat plants.
If I understand your question correctly, Dark, Psychic, and Grass are weak against Bug.
The Pokemon that are weak to bug Pokemon are Pokemon that are the grass, poison, or psychic type.
Grass and I think bug not sure
they r weak against fire, flying, poison, bug and ice
grass, ice, bug, and steel. Grass and ice takes more damage.
Grass type Pokemon are weak against Ice, Fire, Poison, Bug and Flying.
Grass, bug, ice, and steel
Grass type Pokémon are weak to Fire, Flying, Ice, Bug and Poison. Ground types are weak to Water, Ice and Grass. So both types are weak to Ice.
Fighting, Grass, and Bug types are "weak against" flying types in all games.
grass and fire Fire, Flying, Ice and Bug
Sidney (Dark type user) 1. Mightyena- weak to Fighting and Bug 2. Absol- weak to Fighting & Bug 3. Shiftry- weak to Fire, Ice, Fighting, Poison, Flying and Bug 4. Cacturne- weak to Fire, Ice, Fighting, Poison, Flying and Bug 5. Crawdaunt- weak to Electric, Grass, Fighting and Bug -------------------------------------------------------------------------------------------------------------- Pheobe (Ghost type user) 1. Dusclops- weak to Ghost & Dark 2. Dusclops- weak to Ghost & Dark 3. Banette- weak to Ghost & Dark 4. Banette- weak to Ghost & Dark 5. Sableye- No real weaknesses -------------------------------------------------------------------------------------------------------------- Glacia (Ice type user) 1. Sealeo- weak to Electric, Grass, Fight and Rock 2. Sealeo- weak to Electric, Grass, Fighting and Rock 3. Walrein- weak to Electric, Grass, Fighting and Rock 4. Glalie- weak to Fire, Steel, Fighting and Rock 5. Glalie- weak to Fire, Steel, Fighting and Rock --------------------------------------------------------------------------------------------------------- Drake (Dragon type user)1. Shelgon- weak to Ice & Dragon 2. Flygon- weak to Dragon and Ice 3. Altaria- weak to Rock, Dragon & Ice4. Salamence- weak to Rock, Dragon & Ice 5. Kingdra- weak to Dragon -------------------------------------------------------------------------------------------------------------- Champion Wallace (Water type user) 1. Wailord- weak to Electric & Grass 2. Milotic- weak to Electric & Grass 3. Tentacruel- weak to Electric, Psychic and Ground 4. Ludicolo- weak to Poison, Flying and Bug 5. Gyrados- weak to Rock and Electric 6. Whiscash- weak to Grass
Okay, so here are all of the types of Pokémon and what they are weak and strong against. Normal - WEAK TO: Fighting STRONG TO: None NO EFFECT: Ghost Fire - WEAK TO: Water, Ground & Rock STRONG TO: Grass, Ice, Bug & Steel Water - WEAK TO: Electric & Grass STRONG TO: Fire, Ground & Rock Electric - WEAK TO: Ground STRONG TO: Water & Flying NO EFFECT: Ground Grass - WEAK TO: Fire, Ice, Poison & Bug STRONG TO: Water, Ground & Rock Ice - WEAK TO: Fire, Fighting, Rock & Steel STRONG TO: Grass, Ground, Flying & Dragon Fighting - WEAK TO: Flying & Psychic STRONG TO: Normal, Ice, Rock, Dark & Steel NO EFFECT: Ghost Poison - WEAK TO: Ground & Psychic STRONG TO: Grass NO EFFECT: Steel Ground - WEAK TO: Water, Grass & Ice STRONG TO: Fire, Electric, Poison, Rock & Steel NO EFFECT: Flying Flying - WEAK TO: Electric, Ice & Rock STRONG TO: Grass, Fighting & Bug Psychic - WEAK TO: Bug, Ghost & Dark STRONG TO: Fighting & Poison NO EFFECT: Dark Bug - WEAK TO: Fire, Flying & Rock STRONG TO: Grass, Psychic & Dark Rock - WEAK TO: Water, Grass, Fighting, Ground & Steel STRONG TO: Fire, Ice, Flying & Bug Ghost - WEAK TO: Ghost & Dark STRONG TO: Psychic & Dark NO EFFECT: Normal Dragon - WEAK TO: Ice, Dragon & Fairy STRONG TO: Dragon Dark - WEAK TO: Fighting & Bug STRONG TO: Psychic & Ghost Steel - WEAK TO: Fire, Fighting & Ground STRONG TO: Ice & Rock Fairy (This is a newly added type in the new game, Pokémon X & Y!) - All we know is that Fairy type is strong against Dragon. Hope this Helps! ;)