If the trunk consists of three thoracic segments, then the pairs of legs are also three. And they are all arranged so that the butterfly can freely move in any direction. Many Lepidoptera have taste receptors on their feet: as soon as the butterfly touches the paw to sweet nectar, the proboscis will immediately unfold and it will be possible to start eating.
There is another difference between the individuals of the same species: in some Lepidoptera, the front legs are hidden under the fleecy cover of the trunk. They use them to clean the antennae, spiracles and other parts of the body. And for movement use only four legs.
Legs in butterflies are designed to stay in one place for a while. Each foot has a set of fixation devices on various surfaces. A secondary role is played by the ability to move around.
All insects, regardless of their species, necessarily have three pairs of legs or limbs. The nearest relative of insects has 4 pairs of limbs – a spider, but it already belongs to another class, arachnids. Therefore, the butterfly, as a bright representative of insects, has three pairs of limbs, six legs, which are located on the chest, which consists of three segments.