Defensively, Bug types often struggle because of their typically low Defense and weaknesses to Fire, Flying, and Rock, all of which are commonly employed offensively. Even their resistances to Ground and Fighting, the two types with the most offensive coverage, are of little use since many Pokémon of both types can learn Rock moves.
However, dual-type Bug/Flying and Bug/Poison Pokémon have an outstanding double resistance to Fighting, which can make up for their low Defense. They also have a double resistance to common Grass moves and can greatly pressure Pokémon of that type. The Bug type is perhaps most effective when paired with Steel, as those two types cover each other against everything but Fire.
In strictly damage-dealing terms, Bug is one of the worst offensive types. Statistically, the Bug type is the weakest among the types as it has the lowest average base stat total among all Pokémon and among fully evolved Pokémon. Furthermore, many fully-evolved Bug-type Pokémon have a base stat total below 400. Although they are super effective against Psychic, Dark, and Grass types, Bug types are unable to deal a lot of damage to many other types, as seven types (Fire, Flying, Fighting, Poison, Ghost, Steel, and Fairy) resist Bug-type moves. Many Grass types have a dual type that eliminates their weakness to Bug, and most pure Grass types have well above average defensive stats, making low-powered Bug type moves almost useless against them.
In Generation I, Bug type can also deal super-effective damage to Poison, though this is reversed as of Generation II. The Bug type does pair effectively with Water and Ice, but their advantage over Psychic types is compromised by the relatively common typing of Bug/Poison types in Generation I, as well as Psychic types with Bug-resistant secondary types.
However, although lacking in stats, Bug-types are by no means ineffectual. Some Bug-types learn powerful status moves such as Tail Glow or Quiver Dance, as well as frequently having access to moves of other types like disrupting powder moves. Although their base power may be lacking, some Bug-type moves have a great utility that hinders the opponent or helps the user, such as U-turn and Sticky Web.
Generation V introduced the most Bug-type Pokémon of any Generation, with 18, and Generation VI introduced the fewest Bug-type Pokémon, with three.
Generation IV introduced the most Bug-type moves of any Generation, with seven, and Generations II and III introduced the fewest Bug-type moves, with three.
The Flying type is one of the two types most commonly paired with the Bug type, with the other type being Poison. However, there are a number of Bug types, despite being able to fly, that are not Flying types, nor have the Ability Levitate, such as Beedrill and Venomoth.
Despite this, the only Bug-type Pokémon that can learn the move Fly, Volcarona and Genesect, are not Flying types.
In Generation I, the Bug type is super effective against Poison-type Pokémon, while the Poison type is super effective against Bug-type Pokémon. As such, this was the only case when two different types were super-effective against each other.
The Bug type was the most common 4× weakness in Generation I, with 11 Pokémon doubly weak to it, mainly due to Poison type having a weakness to it at the time.
No Pokémon gains the Bug type upon evolving that did not already have it. It shares this distinction with the Normal type.