Experimental approach to the dislodging effect and the mortality of a pesticide in the yellow scorpion Tityus serrulatus

Abstract

Accidents with scorpions are a problem in several regions of the world. In Brazil, the number of accidents is sometimes higher than 160k/year, and the responsible for most accidents and deaths is the yellow scorpionTityus serrulatus. Unfortunately, there are few publications testing the effectiveness of most of the products for chemical control of scorpions. Using the pesticide Bifentol, we tested: I–the effect of the pesticide on the mortality ofT.serrulatus, II–whether the scorpion avoids areas with pesticide and, III–whether it leaves the shelter if pesticide is applied. In the first experiment, we applied pesticide or water on the dorsal region of the scorpion or substrate according to treatment. For five days we noted whether the scorpion slide (dead) or clung to the substrate (alive) after turning the arena vertically to left and right. After five days, no pesticide-treated scorpions were alive while all water-treated scorpions were. In the second experiment, we placed two shelters, applied pesticide and/or water inside the shelter. We then released a scorpion on the opposite side. We scored latency to enter one of the shelters and the choice made by the scorpions. We did not find differences in latency or in the choice made. In the third experiment, we applied the pesticide or water to the shelter where the scorpion was being maintained, and, on the following day, we recorded whether the scorpion had left the shelter. None of the scorpions left the shelters and only one died. Thus, we obtained evidence that a pesticide can kill scorpions, but we did not find a dislodging effect.