CONICET | Buscador de Institutos y Recursos Humanos

Spiders are found among the most important predators of plague insects of numerous agricultural systems. Theyare the most numerous representatives of the Class Arachnid and are widely distributed in numerous ecosystems.Due to multiple variables, living beings are exposed to quantitative transitions of their energetic reserves, whichaffect their sensitivity before the different xenobiotics. In the present study we evaluate the effect of cypermethrin(pyrethroid) on different metabolic/energetic stages of the spider Polybetes pythagoricus (Sparassidae).We firstly studied LD50 of cypermethrin on young, males and, pre-vitellogenic and post-vitellogenic females. Theactivity of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transferase(GST) and acetylcholinesterase (AChE) was analyzed. Results indicate that young have a higher caloric contentcompared to adults, females have a higher caloric content than males and vitellogenesis generates a great calorydecrease in females. The LD50 was significantly lower in young (10%) (103 ng/g weight) in relation to the threemodels of adults (969?1108 ng/g weight). Vitellogenesis causes an increase of free radicals as a result of thedifferent metabolic processes which manifest as an increase in the lipid peroxidation. Doses at the LD30 and LD40levels of cypermethrin did not generate alterations in any of the enzymes analyzed in young, this fact mayprobably provoke an increase of lipid peroxidation (evaluated as a great MDA increase). The activity of theenzymes linked to oxidative stress was altered by this doses in the three adult models, the enzymatic activityCAT, GR, and GST was sex-dependent. Post-vitellogenic females showed a greater activity of CAT, SOD, GST andGR before the xenobiotics than pre-vitellogenic ones, probably as a consequence of metabolic stress generatedduring vitellogenesis.