Scorpions are present across the Hawaiian Islands, a fact that often surprises visitors and new residents. These arachnids, like many other invertebrates, are not native to the islands and were introduced through human activity. The presence of this single, invasive species highlights a common ecological pattern in Hawaii.
The Hawaiian Scorpion Species
The sole species of scorpion established in Hawaii is Isometrus maculatus, commonly known as the lesser brown scorpion. This invasive species has achieved widespread distribution across tropical areas globally, originating in Asia, likely Sri Lanka. Its dispersal was facilitated by cargo and trade over time. Adults typically measure between 45 and 75 millimeters in total length. They feature a pale yellowish-brown to dark brown body that is often mottled or spotted over the abdomen and legs.
Typical Habitats and Distribution
The lesser brown scorpion is well-established across most major Hawaiian islands, including Oʻahu, Maui, Hawaiʻi (the Big Island), and Kauaʻi. This species thrives in the warm, humid climate and often lives near or within human structures, flourishing in both natural and urban environments. They are nocturnal creatures, spending their days hiding in sheltered, moist locations. Common outdoor habitats include under rocks, leaf litter, woodpiles, and yard debris. Indoors, they seek dark, damp areas like basements, washrooms, or crevices in buildings.
Understanding the Risk
The medical implications of a sting from the Hawaiian lesser brown scorpion are mild. Its venom is non-neurotoxic to humans, meaning it does not affect the central nervous system. There have been no reported fatalities in Hawaii associated with this species. A sting is immediately followed by localized, intense burning pain at the contact site, often compared to the sensation of a bee sting. This is usually accompanied by localized swelling, warmth, and possibly numbness or tingling in the affected area.
In some cases, systemic symptoms like muscle pain, headache, or nausea may develop, but these effects usually dissipate within 24 hours. If stung, clean the area with soap and water to prevent secondary infection. Applying a cold compress or ice pack helps reduce pain and swelling, and over-the-counter pain relievers can also manage discomfort. Seek immediate medical attention if symptoms worsen or if signs of a severe allergic reaction appear, such as difficulty breathing, generalized swelling, or hives. Young children and older adults are sometimes more susceptible to stronger symptoms, so their condition should be monitored closely.