Resumen

The success of a predator depends on its ability to capture, manipulate, detect and consume its prey; This is a consequence of the particular strategies that include defense mechanisms and range of availability that each sex has at the time of feeding. In this way, sexual dimorphism (SD) can have implications in trophic behavior, causing a reduction in intersex competition for trophic resources (intersex partition of trophic niche). Among arachnids, scorpions have sexual dimorphism in different parts of the body, one of them being the pedipalps. The genus Chactas, belonging to the family Chactidae, has males and females with a marked sexual dimorphism, not only in body mass (size), but also in their pedipalps (chelas). These allow to capture and manipulate the prey, which makes them an excellent model to determine the trophic implications of SD in arachnids. For this work, aspects of biomechanics were established through the measurement of the pedipalp strength of males and females collected in the municipality of Ibagué (Tolima, Colombia). Likewise, the predatory behavior on different types of prey was evaluated with the following variables: acceptance rate, immobilization time, use of the stinger and frequency of use of the stinger. The results suggested intersex differences in the number of attacks, use of the stinger, frequency of use of the stinger, as well as the strength of the pedipalps where the females presented greater strength with respect to the males. On the other hand, there were no significant differences between sexes for the acceptance rate and immobilization time