Get out the hanky for spider Number 16.
No, not so you can pick her up and flush her down the toilet but because the world’s oldest known spider has died at the age of 43. As Henry Bodkin at The Telegraph reports, the eight-legged, quadragenarian that lived in the Australian outback died after being attacked by a parasitic wasp.
According to a press release, Number 16 was first noticed in 1974 soon after she was born at the North Bungulla Reserve near Tammin in southwestern Australia. She was selected by researcher Barbara York Main as a participant in a long-term research study about trapdoor spiders, Giaus villosus. Main monitored the spiders for years, and according to Michelle Starr at ScienceAlert, marked and observed over 150 spider burrows.
But Number 16 was the only survivor of the early days of the project—spiders 1 through 15 all died over the decades. No. 16 was last seen alive in the spring of 2016, but when researchers checked on her in October of that year, they found that a parasitic wasp had infiltrated the burrow, which was already falling into disrepair. The researchers came to the conclusion that the spider was dead or would soon be eaten from the inside out by the wasp larvae.
Despite the gruesome death, her legacy lives on. “To our knowledge this is the oldest spider ever recorded, and her significant life has allowed us to further investigate the trapdoor spider’s behavior and population dynamics,” says Leanda Mason of Curtin University, lead author of a paper about Number 16 published in the journal Pacific Conservation Biology.
The life spans of spiders vary considerably from species to species. While many common house spiders live a few years some can survive up to seven years. Tarantulas, on the other hand, can live into their 20s. The arachnid with the longest known lifespan prior to Number 16 was a 28-year-old tarantula found in Mexico.
Why did the trapdoor spider hang on so long? As the AFP reports, there are two contributing factors.
Unlike male trapdoor spiders which leave their burrows and range the landscape looking for food, the females stay in or near their burrows their whole lives. This lifestyle provides protection from potential predators and allows the female to conserve energy.
“Through Barbara's detailed research, we were able to determine that the extensive life span of the trapdoor spider is due to their life-history traits, including how they live in uncleared, native bushland, their sedentary nature and low metabolisms,” Mason says in the press release.
The average trapdoor spider can live from 5 to 20 years. It’s hard to say whether Number 16 had great genes, was particularly cautious or was just plain lucky. In any case, her death came as a blow to the researchers. “We’re really miserable about it,” Mason tells Bodkin. “We were hoping she could have made it to 50 years old.”
According to the press release, this rare long-term study will help researchers understand how climate change and deforestation impact this and similar species. The impacts of climate change are largely detrimental for spiders, driving many of the world’s cave spiders toward extinction. But to the dismay of anyone with arachnophobia, climate change may have the opposite effect on other species, leading to more frequent breeding, larger body size and quicker spider sprints.