ROME, Sept. 21 (Xinhua) -- Fire ants, one of the world's most aggressive invasive species, have recently appeared on the southern Italian island of Sicily. At least 88 nests have been discovered near the city of Syracuse. These pests can kill small livestock, overwhelm crops, and can cause illness and even death in people.
Analysts say that the major factors behind their spread are international trade and tourism combined with a changing climate, and the problems they are causing are diverse.
"Ecosystems evolve over millions of years and are delicately balanced," Adriano Martinoli, a researcher with the Department of Theoretical and Applied Sciences of Italy's University of Insubria, told Xinhua recently.
"When a new species is introduced to an ecosystem, they can thrive because they aren't part of the balance. They may not have any natural predators, and so they expand and they can impact the entire ecosystem," Martinoli said.
Italy is witnessing many of these problems earlier than other countries due to its location in the middle of the Mediterranean Sea -- which makes it more vulnerable to a changing climate -- and its status as a major European exporter and importer, said Martinoli.
Fire ants are not the sole headache for Italy. The blue crab, a native of the Atlantic coast of North America, first appeared in Italy in the 1950s. But its reach expanded dramatically last year due to warmer sea temperatures. Now, the crab is obliterating native species important to Italy's culture and cuisine, including mussels, clams and oysters. Furthermore, blue crabs are cannibalistic -- they will eat smaller crabs of their own species once the native species are gone.
The government of Italy is considering a state of emergency and is encouraging people to eat the invading crabs. Websites have published blue crab recipes, and the crabs now appear on restaurant menus. Prime Minister Giorgia Meloni was even photographed holding a plate of cooked blue crabs while on vacation last month.
According to Martinoli, the forces behind the spread of blue crabs -- rising sea temperatures and a lack of natural enemies -- are probably too powerful for a strategy like the government's to have a lasting impact.
The tiger mosquito is also on the list. Native to Southeast Asia, it brings the risk of yellow fever and dengue fever to Italy. The pine tortoise scale, a small insect originally from North America, is slowly killing off the majestic pine trees of Rome and other Italian cities.
"These issues will cause an increasing number of problems, both in terms of human health and in changes to ecosystems," Martinoli said. "Options are limited and so it's something the world will have to adapt to."