By Hannah Corsini, Kingfisher Writer

Published December 10th, 2023

A pest in Antarctica? An Indian meal moth has been captured within the Brazilian Comandante Ferraz research station on King George Island, South Shetland Islands. This report emphasises the constant threat of anthropogenic pollution to the natural environment in all parts of the world.

When you picture Antarctica, what do you see? Movies and television shows have long portrayed this geographical region as a cold, desolate continent hostile to humans. Yet what once was remote, undisturbed land has since been embraced as a site of international research, visited by thousands of people each year.

Permanent research stations have been established on the ice-free area of the Fildes Peninsula, located on King George Island, one of the South Shetland islands off of mainland Antarctica.

But human presence has brought its issues. Anthropogenic pollution can come in the form of diesel, heavy metals and microplastics. Humans also have the potential to introduce foreign species and contaminants一and a recent find has illuminated this. In late 2021, a micromoth was found in a research station kitchen on King George Island.

The moth was frozen and transported to the University of Brasilia for analysis, where it was identified as a male Plodia interpunctella or Indian meal moth.

‘Humans also have the potential to introduce foreign species and contaminants.’

Indian meal moths are distinguishable by the striking patterns on their wings, with their forewings being grey at the tip but reddish-brown at the tail, and their hindwings having pink or red copper scales unique to the species. In the absence of colour on worn specimens, they can also be identified by their forward-facing mouthparts and distinct vein patterns. This particular moth also had its genitalia dissected, and the distinctive appearance further helped to identify it as the Indian meal moth.

Indian meal moths are a common pest, reported as one of the most frequent causes of food infestations across the world. Although unable to cause direct damage to food or packaging themselves due to the functional limitations of their fluid-sucking mouthparts, adults can lay eggs inside the food, and from there, their larvae can hatch and cause damage.

Moths can exist in a broad range of climates and are found globally一making their appearance in Antarctica a risk for a biological invasion. A ‘biological invasion’ occurs when a species一known as an ‘alien’ species一colonises a new geographical location isolated from its existing population.

One particularly famous example of biological invasion is that of Japanese knotweed, this was a serious threat to biodiversity both in Europe and North America. Originally native to Japan, it was brought to the Royal Botanical Gardens in Edinburgh, Scotland in 1854, spreading exponentially from there across the United Kingdom.

‘Indian meal moths are a common pest, reported as one of the most frequent causes of food infestations across the world.’

The Antarctic ecosystem has been evolving independently of humans for thousands of years. Because of the climatic conditions, very few species occur naturally on the continent. For this reason, alien species can have a wide-ranging influence on Antarctic ecosystems, wreaking havoc such as biodiversity loss and fundamental changes to ecosystem processes.

P. interpunctella is part of the Lepidoptera order一the order of insects which comprises butterflies and moths, known for their wide dispersal behaviour. P. interpunctella is not the first lepidopteran which has been sighted in the Antarctic realm, there are records of at least five lepidopteran species spotted in the subantarctic region, all with the dangerous ability to cause a biological invasion.

One of these, Plutella xylostella, or the diamondback moth, is now well-established on Marion Island of sub-Antarctica, where it has damaged the cruciferous plant population, with its larvae infesting and eating the native Kerguelen cabbage. Its cold tolerance and rapid generation time made it the perfect candidate for an invasive event.

‘There are records of at least five lepidopteran species spotted in the subantarctic region, all with the dangerous ability to cause a biological invasion.’

This is why new species to the Antarctic realm are monitored so closely, and control measures are taken to prevent their presence. In 2025, Marion Island will undergo the world’s biggest single eradication operation一to remove the house mice, first introduced by 19th-century seal hunters and then quickly becoming a threat to the island’s invertebrates and plants, then moving onto the chicks of the native seabirds.

The operation will involve a fleet of helicopters spraying the entire 30,000-hectare island with rodenticide, to kill off the mice. This may seem extreme but without these measures, the native albatross is predicted to become locally extinct, along with 18 of the 28 seabirds which breed there.

The physiological temperature requirements of P. interpunctella mean that it is unlikely to survive out in the open in Antarctica, and more likely to be found in warmer environments. There have been cases where similar species have established themselves in Antarctic research stations and proved difficult to eradicate.

Given the trouble that the Indian meal moth has caused to food stocks around the world, its establishment in these research stations would be disastrous.

Alien species tend to surface in Antarctica accidentally via cargo ships delivering supplies to research stations. Supplies to the Comandante Ferraz research station, where the P. interpunctella was found, are primarily transported to the station by Brazilian navy vessels from Rio de Janeiro and Rio Grande, but the station also receives cargo from Chile.

‘In 2025, Marion Island will undergo the world’s biggest single eradication operation一to remove the house mice.’

This means that it is hard to ascertain where the specimen came from. Thankfully, it appears to be the only one of its kind, with no traces of other adults or moth larvae, but the scientists who found it advise more rigorous control measures, such as freezing food for 24 hours before transportation to prevent the calamity of an invasion.

With Antarctica already experiencing large-scale ice loss and glacier retreat, Antarctic ecosystems are already in a precarious position. The recent discovery of P. interpunctella in the Comandante Ferraz research station, though seemingly a harmless and isolated incident, is an echo of the historical introduction of alien species to the continent, with dangerous consequences. If more care is not taken in our treatment of the land, humans may be the unmaking of the Antarctic.

Featured Image: Acaro / Pekka Malinen, Luomus | Wikimedia Commons

References

---

---

Author

---

Related Articles