Warmer Climate, Possible Threat to Antarctica’s Only Native Insect Population Despite Its Ability to Endure Extreme Conditions

A recent study showed that the Antarctic midge has evolved to survive in extreme conditions, yet a warming climate could endanger its existence.

The Antarctic midge, as specified in a Science report, might be tinier than a pea, although it is the largest land animal on the continent, not to mention the only native insect.

Unlike temperate-zone midges that swarm around water, the Antarctic midge, also called "Belgica Antarctica," is flightless and lives in the Earth's moist pockets on the Antarctic Peninsula's nearby islands.

In addition, the species lives at a slower pace, taking two years to complete its life cycle and spending most of its life as a larva.

The Ability to Endure Stressful Conditions

According to an author of the study published in the Functional Ecology journal, insect psychologist Nicholas Teets, from the University of Kentucky, the brown, wormlike juveniles "are not remarkable" in appearance. However, he added, they are remarkable in their ability to endure stressful conditions.

The midge has had 40 million years to perfect its survival tactic. It endures the brutal winter temperatures in the same manner eccentric billionaires preserve themselves in science fiction movies-specifically; they freeze.

To avoid damage to internal tissue by icy crystals, overwintering larvae are losing up to 70 percent of their body fluids. Once their bodies get frozen, these larvae spend around six months in a suspended state, also known as "diapause," during which they do not eat, move, or do anything.

With Antarctica warming quickly due to climate change, Teets and his colleagues wondered how small changes in winter temperatures might impact the midges.

Midge Larvae Set at 3 Temperatures

To reach their finding, the researchers collected larvae from various islands off mainland Antarctica and placed them in incubators at three temperatures. These include the one that represents a cold Antarctic winter at -5°C, the typical winter at -3°C and the warm winter at -1°C

Six months later, the study investigators discovered that the larvae in the warm winter incubator had slower movement, smaller energy stores, and lower survival than those in colder conditions.

A related Agadir-Group report said that the exhausted energy stores could mean trouble for the reproduction of midges. Larvae are coming out of diapause and rapidly turn into adults that do not have functional mouths, so they can depend on their reserves to get through the breeding season.

Warmer Climates

According to The University of Cincinnati's Joshua Benoit, who was not part of the study, if warmer winters mean the larvae a burning through many more of their reserves, ultimately, they will end up getting extinction from some islands.

Because Antarctica has few species living only on land, the loss of even a single midge could reshape the food web.

However, Teets explained, "It may not be all doom and gloom," adding that if the winter is both shorter and warmer, these species could begin their feeding and growth cycle sooner in the summer," making up for the stores they lost.

Teets also explained that the next step is to monitor the populations of midges in the wild and find out how they react to changing temperatures.

He noted, though, that "winter fieldwork in Antarctica," when the ground is frozen solid, changes, and thus, it could take some time to document any changes.

Related information about Antarctica's only native insect is shown on Animal Fact File's YouTube video below:

Check out more news and information on Antarctica in Science Times.