Locusts of mordor

Known as the scourge of the pathetic foliage of Mordor, locusts appear only in the months of Narbeleth and Hithui. During the end of the growing season (if it can be called as such), the locusts significantly increase in number. Once the population has swelled, hordes of ravenous insects raze the sparse vegetation of the Gorgoroth plain, then just as suddenly disappear, only to return the following year.