Known as the scourge of the pathetic foliage of Mordor, locusts appeared only in the months of Narbeleth and Hithui. During the end of the growing season (if it could be called as such), the locusts significantly increased in number. Once the population had swelled, hordes of ravenous insects razed the sparse vegetation of the Gorgoroth plain, then just as suddenly disappeared, only to return the following year.