Earthweek: a diary of the planet

For the week ending Friday, March 18. By Steve Newman

Hornet ‘sex traps’ The invasive Asian giant hornet that has in recent years ravaged honeybee hives in British Columbia and Washington could be wiped out with “sex traps” developed by U.S. and Chinese researchers. Writing in Current Biology, they say key ingredients in the sex pheromones of the “murder hornets” can be put into traps, luring the males from the queens. “In two field seasons, we were able to rapidly collect thousands of males that were attracted to the odor,” a co-author said.

Farming shift

Researchers have developed a map that shows where the world’s major food crops could successfully be moved to combat climate change and greatly reduce the need for irrigation. Writing in Nature Communications Earth & Environment, they propose expanding agriculture around the corn belt in the American Midwest and south of the Sahara desert. This would allow vast tracts of farmland in Europe and India to revert to their natural ecology, allowing CO2-eating forests to grow back in the process. Water resources could be more targeted to the planet’s thirsty and growing human population.

Vanishing ice

Fresh data from NASA’s ice-monitoring CryoSat-2 and IceSat-2 spacecraft reveal that the sea ice surrounding the North Pole is thinner and disappearing more quickly than previously thought. Using radar and lidar, the satellites can measure the thickness of the ice with a resolution of about a half inch. With that data, a report says that the Arctic Ocean has lost about a third of its winter sea ice cover over the past 20 years. Scientists say ice that once did not melt over the summer has lost an average of about 1.5 feet in thickness just since IceSat-2 began operating in 2019. This shrinking leaves only much thinner seasonal ice, which melts completely each summer.

Gorilla thirst

Climate change is causing East Africa’s two endangered mountain gorilla populations to have to drink more frequently, which seems to make the primates especially susceptible to the region’s warming climate. The rain forest dwellers typically get most of their hydration from the food they eat. But the warmer weather in recent years has caused them to become more reliant on water from streams, puddles and swamps. Water is believed to help maintain a healthy body temperature.

Deluge aftermath Australian health experts warn that there will probably be a rise in serious mosquito-borne disease, along with more bites from snakes and spiders, as the catastrophic inundation in the southeast subsides. New cases of Japanese encephalitis have already been reported, prompting authorities to expand vaccinations, especially for pig farm workers and their families because of their increased chances of getting bitten by infected mosquitoes. With funnel web spiders being discovered in more homes around the flood disaster zones, anti-venom manufacturers have stepped up production as a precaution.