Scientists in Australia are deep-freezing koala eggs and sperm as a "genetic backup" to save the wild population from future extinction.

The backup could be used to create healthy koala embryos through artificial insemination and in vitro fertilization (IVF), the researchers said in a statement. When koalas (Phascolarctos cinereus) die, unique traits and diverse genes that may help them adapt to changing environments are lost, but the new project offers a way to store this valuable material, the team said.

"Losing genetic diversity can weaken future generations and decreases the ability of the species to adapt to challenges," Andres Gambini, a reproductive biologist at the University of Queensland who is involved in the project, said in the statement. "This project will create a safe and systematic way to rescue and preserve koala spermatozoa and eggs to support future conservation programs."

Australia is facing a paradox with its koalas. In some regions of Queensland and New South Wales, koala populations have crashed by as much as 80% since the late 1990s due to deforestation, bushfires, drought and disease. This prompted the Australian government to change koalas' conservation status in their eastern range from "vulnerable" to "endangered" in 2022.

Meanwhile, in parts of southern Australia, koalas are overabundant. However, the places where koalas are currently thriving may not be able to support a booming population much longer, because the animals are overbrowsing and killing the trees they need to survive, recent research suggests.

To protect against koalas' decline, the scientists will freeze koala reproductive cells in liquid nitrogen (LN2), which has a boiling point of minus 321 degrees Fahrenheit (minus 196 degrees Celsius). This method would enable the team to cryopreserve the cells for several decades until they are needed, said Vincent Lynch, an evolutionary developmental biologist and associate professor of biological sciences at the University at Buffalo in New York.

"I've successfully woken cells up that were frozen in LN2 a couple of decades ago," Lynch, who is not involved in the koala project, told Live Science in an email.

The sperm and eggs will be supplied by wildlife hospitals that will harvest sex cells from dead koalas or koalas that can no longer breed due to disease or trauma, according to the statement.

"Every year, many koalas are admitted to wildlife hospitals because of illness or injury and sadly, not all of them survive," Gambini said.

The researchers will then test the cells for Chlamydia pecorum, a highly contagious and deadly form of chlamydia. In koalas, this infection causes painful urinary tract infections, gastrointestinal issues, and conjunctivitis, which can lead to blindness. It can also cause infertility in females. C. pecorum is one of the main contributors to koalas' decline in recent years, with infertility driving a sharp reduction in the number of koala joeys being born. In the worst-affected populations, situated mostly in Queensland and New South Wales, almost 90% of koalas are infected with chlamydia.

If the reproductive cells contain C. pecorum, "we have the technology now to remove the infection from the samples," Steve Johnston, an associate professor of animal reproduction and captive husbandry at the University of Queensland who works on the koala project, said in the statement.

In 1998, Johnston was part of a research team at the University of Queensland that created the world's first koala joey born through artificial insemination. The new project also builds on a 2025 study, led by Gambini, that produced the first-ever IVF kangaroo embryos. (These did not result in live births; at the time, the scientists said that would take another decade.)

It's unclear how many sperm and egg cells the researchers plan on freezing, and it's hard to say how many cells they would need to ensure the survival of healthy koala populations, as the number of cells required is probably increasing with time, Lynch said. As koala populations shrink, genetic material is being lost at an accelerating pace, so the team will have to get more samples as time goes on to obtain the same amount of diversity.

The project does not replace more traditional conservation approaches — such as habitat protection, disease management and population monitoring — but researchers cannot afford to wait until populations are smaller and genetic diversity is harder to recover, Gambini said.

Although conservationists are concerned about the fast rate of koalas' decline, "there is a chance" that scientists can save the species through cryopreservation, Lynch said.

"I support multipronged approaches like this," he said. "By preserving the environment with traditional conservation we allow re-introductions because the species have somewhere to live."

Engineers have designed a waterproof "diving suit" for cyborg cockroaches that enables the hybrid insects to survive and roam underwater for up to three hours. This function expands the capabilities of cyborg insects and could one day be deployed in disaster zones, according to the team.

A built-in oxygen generator and silicone tubes deliver the gas directly to a cockroach's breathing holes, known as spiracles. The design is adapted for use in low-oxygen conditions as well as submerged environments, the researchers said in a new study published June 29 in the journal Nature Communications.

"Our approach combines a soft waterproof shell with a simple yet reliable chemical oxygen generator," study co-author Shinjiro Umezu, a professor in the School of Creative Science and Engineering at Waseda University in Japan, said in a statement. "This allows the insect to retain its natural mobility while being protected from an environment that it cannot normally survive in."

Cyborg insects are living insects that have been fitted with electronic controllers that guide their movements. Researchers have previously used them in search-and-rescue operations to access and investigate hard-to-reach areas; for example, they were used in rescue efforts after the devastating magnitude 7.7 earthquake in Myanmar in March 2025 that killed at least 3,700 people and injured 4,800 more. The advantage of cyborg insects over tiny robots is that the former employ insects' muscles to move, whereas the latter rely on high-power batteries that consume energy and can run out of steam.

The cyborg insects deployed in Myanmar were developed in the laboratory of Hirotaka Sato, senior author of the new study and a professor in the School of Mechanical and Aerospace Engineering at Singapore's Nanyang Technological University.

Sato has spent more than a decade pioneering cyborg insect technology. He and colleagues hope the new diving suit will extend cyborg insects' operational range to include flooded and partially submerged areas in disaster zones.

The suit consists of a flexible shell, four silicone tubes that attach to the spiracles and a transparent, 3D-printed oxygen tank. To make the tank produce oxygen, the researchers sprinkled manganese dioxide onto a highly absorbent sponge inside the tank. They then injected a small amount of diluted hydrogen peroxide, which breaks down slowly in the presence of manganese dioxide to produce oxygen. Finally, the team sealed the tank with ultraviolet adhesive to prevent leaks.

"The key engineering challenge was to build a system that was small, light and flexible enough for the insect to wear, while still producing enough oxygen for long-duration underwater movement," Umezu said.

The silicone tubes send oxygen straight into the thoracic spiracles, while the abdominal spiracles, which are lower down the insects' bodies, take in the oxygen contained in the suit.

"Our new insect diving suit works like the oxygen tank used by human divers," Sato said in the statement. The silicone tubes can be attached and removed without pain or harm to the insect, the researchers added.

The researchers tested the suit on a cyborg Madagascar hissing cockroach (Gromphadorhina portentosa), which they placed in a water tank and later sent into a plastic tube that simulated submerged and low-oxygen environments.

The suit enabled the cockroaches to roam underwater for up to three hours, raising the prospect that cyborg insects, including locusts and beetles, could one day be used to inspect flooded pipes, drains, tunnels and other hard-to-access places.

Next steps include improving the diving suit to potentially include sensors and a navigation system; and testing the design in simulated disaster environments, according to the statement.