Explanation of Names
The name Hadrurus has its origins in Hades, the underworld.
There are 8 species in Hadrurus, with 3 in the USA and 5 others in Mexico.
Species in this genus range from 100 mm to 120 mm (4-5 inches) and are the largest scorpions in North America (with the exception of a few Diplocentrus species).
Hadrurus scorpions are readily identifiable by their setose appendages, especially the metasoma (tail) and pedipalps. Taxonomically, the genus and family Iuridae have the unique character of an enlarged darkened tooth on the ventral margin of the cheliceral movable finger.
is the well-known Arizona desert hairy scorpion and has 3 "accessory" trichothria at the base of the movable finger of the pedipalp chela
(hand), and the interocular crescent is unpigmented contrasting the rest of the dorsum which is dark. There is a dune-specific variety that is entirely lacking pigment except for around the interocular crescent where a dark band forms a distinct crescent. It is found throughout the Sonoran Desert in Arizona into southern Utah and southern Nevada, and well into S California and into Baja.
H. obscurus is related to H. spadix by lacking the 3 accessory trichobothria. It also has the darkend pigment extending into the interocular crescent but not to the anterior margin. Many specimens have a faint pale strip extending along the dorsal midline. A pale variety has carapace markings that form a "V" pattern that "covers" the eyes instead of a rounded crescent situated somewhat behind the median eyes. This one is known only from California from near Hollister and Fresno and down the Mojave Desert to north of Calexico.
H. spadix has a completely melanic carapace and dorsum and also lacks the 3 trichobothria as above. It is found in southern Idaho, eastern Oregon, and much of Utah and Nevada (possibly W Colorado) to near Flagstaff and Kingman, Arizona.
Desert hairy scorpions are found in the western states of Idaho, Oregon, Utah, Colorado, Arizona, Nevada, and California, and in Mexico in Baja California and Baja California Sur, Sonora, and the central Mexican states of Guerrero, Puebla, Oaxaca, and Veracruz.
A wide range of habitats from sand dunes to rocky hillsides where they dig extensive burrows, often to 20 feet deep!