Italy's farming association Coldiretti says millions of locusts are causing "considerable damage" to parts of the island, which runs a risk of "seriously compromising part of the harvest".
Farming areas near the city of Nuoro have been particularly affected by the swarm, which was described by experts as the worst invasion in at least 60 years.
The local newspaper La Nuova Sardegna said parts of the 2,000 hectares of land affected had turned to "carpets of locusts" that amounted to "almost biblical" proportions.
Leonardo Salis, the president of Coldiretti's Nuoro chapter, said the locusts were "devouring everything they encounter" and in some cases "leaving animals without grassland".
He added: "We have turned to institutions at all levels - municipality, provincial and regional - to tackle the problem, despite knowing that for the current season we are late."
Little can be done to counter the current issue, and farmers have been forced to use hay bales delivered from other parts of the island, which increases costs.
Locust expert Alexandre Latchininsky, who is an official with the Rome-based UN Food and Agriculture Organisation, said reasons for the high number of locusts were not clear.
But Coldiretti maintains that sudden high temperatures following from a cool month of May are to blame.
The group says the eggs laid in autumn may have reached maturity in the sudden warmth, prompting the new bugs to search for food.
It is now looking to the government to help with preventing such an invasion again, and says cultivating land can ward the insects off from laying their eggs.