The Asian Forest Scorpion (Heterometrus longimanus) is often confused with the Malaysian Forest Scorpion (Heterometrus spinifer), which is often referred to as the "Asian Forest Scorpion" in the pet trade. The Malaysian species is similar to the Asian but they are distinct and individual species.
Like the Malaysian Forest Scorpion, the Asian Forest Scorpion is very similar to the Emperor Scorpion in shape and coloration. But the Asian Forest Scorpion has a stronger sting than the pandinus species. The sting is said to equal that of a hornet. Additionally, Asian Forest Scorpions are known to be more territorial. Asians may also exhibit aggression towards members of their own species. For both of these reasons it is recommended for more experienced hobbyists rather than for beginners. In the wild they usually live under logs and other natural debris. They are terrestrial animals, but may burrow to some extent. In the wild, they feed primarily on insects. Their venom is only slightly toxic, although some people may be more sensitive to it then others. The bite of the Asian Scorpion is reported to be more painful than that of the Malaysian, though their LD-50 (lethal dose in 50 percent of lab animals tested - usually mice) ratings are almost the same. This may be due to the fact that they have a slightly shorter and stubbier aculeus (stinging barb). When threatened, they rarely use their tail to attack. Instead, they use their large pedipalp, which is quite capable of drawing blood. Asian Forest Scorpions found in the wild are usually more aggressive then those raised in captivity, although many quickly loose their aggressiveness if handled frequently. They can be kept in small groups, although that is not suggested. They have a medium to long life span and are quite hardy.
The Asian Forest Scorpion is a large scorpion, averaging four to four and a half inches in length. They are smaller than the Malaysian variety, which grows to an average of 6 inches in length. The easiest way to distinguish the Asian Forest Scorpion from the Malaysian Asian Scorpion is by examining the claws. The Malaysian's pincers have very smooth grooves in the sides, while the Asian's pincers have no grooves. Additionally, the Asian's pincers are slightly bubbled. The bubbling is similar to that seen in the Imperial Scorpion's claws is not nearly as extreme. The Malaysian doesn't have bubbled pincers at all, their pincers are almost perfectly smooth. Another difference between the two species is their coloration. The Asian's coloration under true sunlight is extremely black with no hints of any other coloration and the Malaysian has a very strong bluish or greenish tint. In direct sunlight the Malaysian does not appear black at all. Lastly, the Malaysian holds a much wider stance when in an attack posture. It spreads its claws all the way apart with the tail aimed directly toward the sky. When the Asian scorpion is in its attack posture, it tends to curl its tail over in a way that is similar to the walking stance, and the pincers are kept almost directly in front of the body as a protection. Both the Asian and the Malaysian Scorpions have a cleft between the bases of the chelicerae and powerful pedipalps (claws) at the base of the tarsus.
The Asian Forest Scorpion is native to Southern Asia.