The effect of microhabitat use on the foraging and diet of the striped bark scorpion, Centruroides vittatus (Buthidae: Scorpiones) in blackbrush habitat of south Texas

Abstract

Abstract. Microhabitat use by predators can be influenced by prey availability, predator size and risk of cannibalism. The preferred microhabitat for a predator can be for foraging, feeding or as a refuge. In this study in south Texas, Centruroides vittatus (Say, 1821) of all size classes utilized both ground and vegetation microhabitats. There was a high proportion of scorpions with caterpillars in legumes and low proportion of scorpions with any of the prey types on the ground. The median height of scorpions with prey did vary, with scorpions on legumes with caterpillar prey the highest and scorpions on other vegetation with dangerous prey the lowest. Intermediate size scorpions used legumes at a high frequency during January–April, and large scorpions used succulents at very high frequency during September–December. Scorpions climbed higher in blackbrush and other legumes than in other vegetation types. These results suggest that scorpions are actively foraging for caterpillars in legumes, and legumes are a quality microhabitat for foraging. The low proportion of scorpions with prey on the ground suggests that C. vittatus feed on prey on vegetation even if the prey was captured on the ground. A possible advantage for the scorpion to handle and consume prey on vegetation is lower predation risk or interference while feeding. The high use of succulents by the large scorpions cannot be explained by foraging success. A possibility is that succulents are preferred refuges by all C. vittatus but smaller scorpions avoid succulents because of the risk of cannibalism by the larger scorpions.