Great Basin Naturalist

Article Title

Scorpions of Utah


The 736 scorpions representing nine species collected in Utah, listed in order of greatest to least abundance, are Vaejovis boreus, V. utahensis, Anuroctonus phaeodoctylus, V. confuses, Hadrurus spadix, V. becki, V. wupatkiensis, H. arizonensis and Centruroides sculpturatus. Centruroides sculpturatus, H. arizonensis, V. becki, V. confuses and V. wupatkiensis are reported from Utah for the first time. Vaejovis boreus is the most widely distributed of the Utah scorpions. Vaejovis boreus and V. confuses occur in both the Great Basin and the Colorado River Basin. Centruroides sculpturatus, Hadrurus arizonensis, H. spadix, V. wupatkiensis, and V. utahensis occur only in the Colorado River Basin, whereas Anuroctonus phaeodactylus and V. becki are confined to the Great Basin. Anuroctonus phaeodactylus, V. boreus and V. confuses occur from the southern to the northern border of the state.

Both males and females were taken from May through October, with greatest numbers in May, June, and July. Females were taken in greater numbers than males. This may be related to their mating habits during the collecting periods, and does not necessarily indicate other than a 1:1 ratio in normal populations.

Morphological variations associated with distribution were distinguishable in two of the species collected—Anuroctonus phaeodactylus and Vaejovis boreus. The mean and standard error computed for the carapace, preabdomen, postabdomen, and telson on these two species indicate a significant morphological variation in the size of the preabdomen between the northern and southern populations.