Japan is home to various creatures, including scorpions. While these arachnids might evoke images of arid deserts and potent venom, their presence in Japan is generally limited. The species found there are not as widespread or dangerous as those in other parts of the world, and encounters are relatively uncommon for most residents and visitors.
Scorpion Presence and Habitats in Japan
Scorpions in Japan are primarily found in warmer, southern regions, particularly within the Nansei (Ryukyu) Islands, including Okinawa, Miyakojima, Ishigakijima, and Iriomotejima. While some species may extend into parts of Kyushu, they are generally not present across the main islands of Honshu.
These scorpions prefer natural habitats like forests and forest edges, seeking shelter under rocks, logs, leaf litter, or within decayed trees and rock crevices. Scorpions are nocturnal, most active at night, which reduces daytime encounters. They are rarely found in densely populated urban centers, favoring less disturbed, rural environments.
Common Scorpion Species and Their Characteristics
The most commonly encountered scorpion species in Japan is Liocheles australasiae, known as the Dwarf Wood Scorpion or Wood Scorpion. These scorpions typically have a flattened, elongated body, colored red to yellowish-brown, with pincers larger than their body and a slender tail. Adults usually measure between 22 and 36 millimeters in length.
The venom of Liocheles australasiae is considered to have low toxicity to humans. A sting typically results in mild, localized symptoms like pain, swelling, and redness, similar to a bee sting. This species rarely stings humans, and due to its small size, its stinger often cannot penetrate human skin effectively. Another species, Isometrus maculatus, from the Buthidae family, has also been recorded in the Sakishima islands.
Encountering Scorpions and Safety
Minimizing scorpion encounters involves simple precautions, especially in known habitats. Check shoes, clothing, and gear left outdoors before use. Exercise caution when moving items like rocks, logs, or leaf litter to prevent accidental contact. Since scorpions are most active at night, use a flashlight when walking in natural areas after dark to spot them.
If a scorpion sting occurs, the immediate area will likely experience pain, swelling, and redness. Clean the affected area thoroughly with mild soap and water. Apply a cool compress or ice pack to reduce pain and swelling. Keep the stung limb elevated and still to slow any potential spread of venom.
Over-the-counter pain relievers, such as ibuprofen, may be used for discomfort. Do not attempt to cut the sting site or suck out the venom. While severe reactions from Japanese scorpion stings are uncommon, seek medical attention if symptoms worsen, appear unusual, or if the sting occurs on the face or neck. Children and the elderly should also receive prompt medical evaluation after a sting.