Scientists tallied the economic damage caused by invasive pests around the globe and determined that two species cause the most impact.

Since 1986, the American bullfrog and brown tree snake have caused $16.3 billion (£13.4 billion) in global harm.

In addition to causing ecological damage, the invasive pair has destroyed crops and caused costly power disruptions.

Researchers believe that their findings will motivate further investments to combat invasive species.

The scientists wrote in Scientific Reports that the brown tree snake was solely responsible for $10,3 billion in damages – in part due to its uncontrolled proliferation across many Pacific islands.

In Guam, where the reptile was inadvertently introduced by U.S. marines a century ago, the sheer current population of the snake causes widespread power outages by slithering over electrical wires and causing costly damage.

More than two million brown tree snakes occupy the tiny Pacific island, with as many as twenty individuals per acre of Guam’s jungle, according to one estimate.

It is believed that invasive species represent a larger threat of extinction to indigenous animals and plants in island environments.

The growing population of American bullfrogs in Europe has necessitated ambitious and costly management programs.

To prevent the spread of the amphibian, which can reach 30 centimeters (12 inches) in length and weigh up to 500 grams (17.6 ounces), officials have been compelled to erect costly frog-proof fencing around known breeding locations.

According to an older EU research referenced by the authors, it cost German officials €270,000 (£226,300) to fence off just five ponds to prevent the amphibians from escaping.

It is reported that the amphibian will consume practically everything, including fellow bullfrogs.

Another species, the common coqui frog, was blamed for causing economic damage differently: its incredibly loud mating song is believed to have contributed to a fall in property values in places where they have established populations.

The authors of the study believe that their findings would motivate further investments in pest management and other biosecurity measures.