treehopper vs planthopper

treehopper and planthopper both are nouns.

Word	Noun	Adjective	Verb	Adverb
treehopper	Yes	No	No	No
planthopper	Yes	No	No	No

As nouns, planthopper is a hypernym of treehopper; that is, planthopper is a word with a broader meaning than treehopper:

treehopper: small leaping insect that sucks juices of branches and twigs
planthopper: related to the leafhoppers and spittlebugs but rarely damages cultivated plants

Other hypernyms of treehopper include plant hopper.

treehopper (noun)	planthopper (noun)
small leaping insect that sucks juices of branches and twigs	related to the leafhoppers and spittlebugs but rarely damages cultivated plants