Black-back Scorpion

🔤 Taxonomy

Hadrurus spadix is an accepted species in Hadruridae. It is sold as the black-back or black-backed desert hairy scorpion and can be confused with dark forms of H. arizonensis. The uniformly dark carapace is useful, but locality and expert identification are safer than colour alone.

📌 Description

Adults usually reach 10–14 cm. The dark carapace and abdomen contrast with paler legs, pincers and tail. This is a strong, long-lived excavator rather than a scorpion for frequent viewing: an established animal may spend most daylight hours inside its tunnel.

The sting is painful but is not generally regarded as medically significant for a healthy adult. Individual reactions and allergy remain possible, and the pincers can break skin. Keep it strictly as a display animal and use a catch cup and long tools for every transfer.

☠️ Venom

This species is venomous. Venom exposure can cause pain, swelling or other systemic effects, and severity varies with species, locality, bite site and the amount delivered. A small wound or apparently dry bite is not proof of safety; every bite or sting requires urgent medical assessment.

If an incident occurs, move away, call emergency services or a poison centre, keep the patient still, remove rings and other constricting items, and follow dispatcher instructions. Do not use a tourniquet, cut or suck the wound, apply ice or electricity, give alcohol or medicines as a home treatment, or attempt to catch the animal. Antivenom choice and dosing are hospital decisions; verify the relevant product and local availability in advance. Sources: WHO snakebite guidance and appropriate species-specific toxinology or medical references listed below.

🌍 Distribution

The verified modern range is in the western United States, from the northern Mojave and Great Basin north into parts of Oregon and Idaho and east toward Utah, Colorado and Arizona. The species occupies dry ground where it can build a stable burrow; the air above may be hot and arid while the tunnel remains cooler and slightly more humid.

🌡 Climate across the native range

Monthly climate normals from reviewed GBIF occurrences across the Great Basin and northern Mojave range:

Weather data by Open-Meteo.com · CC BY 4.0 · Monthly normals calculated by Herpeton Academy from daily archive values.

Location references use GBIF.org occurrence data where available; original occurrence records retain their source dataset licenses.

⚖️ Legal status

As checked on 17 August 2026, H. spadix was not listed in the CITES Appendices or the EU wildlife-trade annexes; the Bern Convention is not relevant to its native range. This does not override state collection rules, national import controls, tenancy terms or local dangerous-animal laws. Prefer documented captive-bred animals and retain the invoice, breeder details and any import papers.

🤌 Husbandry

House one animal per enclosure. Hadrurus are territorial and a temporary pairing can end in cannibalism. Quarantine a new arrival for 60–90 days in a secure, simple enclosure with dedicated tools. Record feeding, body condition and moults; wild-collected animals need particularly close checks for dehydration, injury and mites.

Before opening the lid, close the room and prepare a catch cup. Never pin the animal or lift it by the metasoma. A clipped or locked lid and ventilation holes smaller than the scorpion are essential.

💡 Lighting

UVB is not required. Use diffuse room or low-output enclosure lighting for 10–12 hours and leave the burrow completely dark. Direct sunlight through glass can overheat a dry enclosure within minutes.

🌡 Heating and temperature

Provide a horizontal gradient: 29–32 °C at the warm end, 22–25 °C at the cool end and 17–22 °C at night. Heat one side externally with a thermostat-controlled mat or cable. Never heat the whole floor under a fossorial animal; a scorpion retreating downward must not enter a hotter sealed layer.

Measure the surface and the deepest accessible substrate. Northern populations experience cold winters, but routine pet care does not require forced cooling. Do not cycle juveniles, thin animals, new imports or animals that have recently refused food.

💧 Humidity and water

Keep the surface dry and well ventilated, supply a shallow water dish, and lightly moisten one lower corner occasionally. That lower refuge is especially useful before a moult. Whole-enclosure spraying encourages mould and mycosis; keeping every layer bone dry risks dehydration and failed moults.

🌿 Enclosure and decoration

Provide 20–25 cm of a compactable sand, clay and soil mixture. It should hold a tunnel when pressed, not pour like dry dune sand. Start a burrow beneath anchored cork or slate. Place heavy stones directly on the enclosure floor before adding substrate so that excavation cannot undermine them.

Do not keep an imported animal permanently on bare paper, but paper or a shallow simple substrate is useful during short quarantine. Leave enough space above the finished substrate that the scorpion cannot reach the lid or vents.

🪳 Feeding

Offer captive-reared roaches, crickets, locusts or similar insects no longer than the scorpion’s carapace. Adults usually take one or two prey every 7–14 days; juveniles take smaller meals more often. Research on this species shows that sting use increases with larger and more active prey, another reason not to offer oversized insects.

Remove uneaten prey within 24 hours and immediately when a moult is approaching. Do not use wild-caught insects or routine vitamin powders.

🦂 Breeding and young

Attempt breeding only with correctly identified, mature animals and enough secure containers for every juvenile. Introduce the pair in a neutral, uncluttered enclosure and supervise without putting hands inside. Separate them after courtship.

The species is viviparous. Gestation can be prolonged and brood size varies; roughly 20–35 young is a useful planning range rather than a guarantee. Neonates remain on the female until their first moult. Do not feed or separate them prematurely.

🩺 Common problems

Collapsing substrate, floor heating and chronic damp are the main setup failures. Watch for fungal patches, mites, marked abdominal thinning, uncoordinated movement, repeated falls or a stuck moult. A settled adult can fast for weeks, so judge body condition and behaviour rather than reacting to one missed meal. Persistent deterioration warrants an exotics veterinarian familiar with arachnids.

📌 Conclusion

This species suits a keeper who wants to observe natural excavation and accepts limited visibility. Deep compact substrate, a safe temperature gradient and disciplined tool-only maintenance must be ready before the animal arrives.

📚 Sources and further reading

• GBIF species record: Hadrurus spadix
• Francke & Prendini (2008), phylogeny and classification of Hadrurus
• Edmunds & Sibly (2010), prey size and sting use in H. spadix
• Veterinary Care of Scorpions
• CITES Appendices
• European Commission: EU wildlife trade