It is quite obvious that we taste our food through our tongue and to decide what is the taste of the food that we are eating. The taste bud is present in the tongue of our body but in case of butterflies it is different they taste their food using their legs as taste bud is present in their feet.
Believe it or not they have taste censors present in their on legs which also informs them that on what type plant they are stand. They cannot eat their foo by biting or chewing but by sucking the liquid from flower and fruits they use to drink liquids in the form of nectar and sap juices from fruits and certain minerals
They have legs which resembles like the straw known as proboscis which performs important tasks initially when butterfly come out of their pupal their proboscis get separated in two parts but as they grow as adult this scattered proboscis they need to accumulate to survive so that they can make long tubular structure so that they can drink the food otherwise they will die due to lack of food.
When proboscis is not used they curled up like garden hose .Often male butterflies do puddling to drink nectar and supplement salts from mud. Thus butterflies inherent nature of taking food is quite astounding and unimaginable.