Feel free to add more food-sucking insects to this list:
walking sticks are a type of insect that sucks the sap of plants through a strawlike mouth
The pharynx of an insect is the first section of the fore gut. It connects the mouth to the gut, and often acts as a pump which sucks liquefied food deeper into the gut for digestion.
Aphid
Symbiosis. Pollination is a good example of this - food for the insect, reproduction for the plant.
catapillar
All of this sucks
An insect is an example of an arthropod.
Aphids, butterflies, many types of flies, mosquitoes, ticks, fleas, squash bugs, and probably many others.
Mosquito.
Depending on your question... A. Mosquito is one. B. A bloodsucking insect is a bug who sucks blood to feed themshelfs or there babies.
Narwhals create a sort of vacuum and sucks up its food
An aphid is a small insect which sucks sap from plants.