Tiny spiders with oversized rumps have been discovered in China. The little arachnids, each about a mm long, represent two new species of orb-weaving spiders. They belong to the Mysmenidae family of orb-weavers, and were described on May 21 in the journal ZooKeys.
Found near giant panda sanctuaries in Chongqing and Sichuan, the mini-spiders live among leaf litter and in caves, making them incredibly hard to spot.
"The best way to find these tiny spiders is to look for their webs," said Jeremy Miller, an arachnologist at Naturalis Biodiversity Center in the Netherlands.
Mysmenidae weave tiny webs in the cavities created by leaves and mosses on the forest floor, and they generally prefer humid climates. Miller, who was not part of this spider-finding team, said he sometimes uses a fine dusting of corn starch to reveal the webs.
"The starch grains stick to the silk and the tiny delicate web becomes quite visible," he said. "In a humid environment, sometime tiny water droplets will collect on the silk, with the same effect."
Trogloneta yuensis, collected in April 2010, is about 1 mm long. Mysmena wawuensis, collected in June 2012, is even smaller -- about 0.75 mm long -- and named after the Wawu Mountains National Forest Park, where it lives. Miller estimates that their webs are probably about the size of a ping-pong ball.
Scientists believe both spiders are endemic to their particular regions, meaning you'd need to travel to China to meet the adorable micro-arachnids -- and perhaps a few of their friends.
"China is currently one of the world's most active regions for discovering and describing new species," Miller said. "With more than 43,000 species described so far, spiders are one of the most diverse groups of animals on Earth and new species are discovered all the time."