Cicadas don't really eat much in their adult stage, they come out to mostly mate. When they are grubs the cicada does eat roots of some plants, but not nearly at the same levels as other more destructive grubs. The adults can do some minor damage to plants and trees when they lay their eggs, but it is very minor.
I like cicadas, the noise they produce is interesting. Doesnt bug me anymore than birds tweeting.
Id hate to be a farmer though, they love to eat everything they see.
I do find the 13-17 year cycles interesting. There must be some evolutionary purpose to this. Maybe they avoid the cataclysm by doing this?
Cicadas don't really eat much in their adult stage, they come out to mostly mate. When they are grubs the cicada does eat roots of some plants, but not nearly at the same levels as other more destructive grubs. The adults can do some minor damage to plants and trees when they lay their eggs, but it is very minor.