a. Sponging Type - Mandible is absent. The insect having sponging type mouth, feeds on (sugar) food by dissolving it in saliva and sucking the liquified food. Eg. Housefly

b. Piercing and Sucking Type - Piercing is via proboscis, which is actually the modification of labium. Eg. Mosquitos, bedbugs

c. Biting and Chewing Type - Mandibles in these insects are sharp, rigid and strong, and they are used to capture, tear and chew the food.
Eg. Grasshoppers

d. Chewing and Lapping Type - The liquid food is drunk by scooping with tongue. Eg. Honeybees

e. Siphoning Type - Proboscis is formed by the modification of maxillae. Eg. Butterfly, moth