Estudios recientes han propuesto que los mántidos macho (Parastagmatoptera tesellata) no son cómplices del canibalismo sexual, siendo capaces de evitar a las hembras bajo condiciones que favorecen el canibalismo. Investigamos si los machos son sensibles al nivel de agresión exhibido por las hembras. 20 machos sexualmente maduros fueron confrontados individualmente con dos opciones: a) una hembra exhibiendo ataques (“hembra agresiva”) cuando un macho arnesado se le acercaba, y b) una hembra que no exhibía ataques (“hembra pasiva”) cuando el mismo macho se le acercaba. Resultados preliminares indican que la preferencia del macho cambia acorde al número de ataques exhibido por la hembra “agresiva” (la cantidad de ataques provocados en las hembras agresivas dependió del tiempo que el macho focal la estuvo observando). Cuando las hembras “agresivas” fueron estimuladas a realizar unos pocos ataques (=6) las hembras “pasivas” fueron preferidas. Las hembras “agresivas” fueron preferidas cuando fueron estimuladas a realizar muchos ataques (>6). Una explicación posible es que la estimulación repetida para provocar intentos de ataque genere en una primera instancia (=6) verdaderos intentos de ataque, mientras que en una segunda instancia (>6) sea percibida como una amenaza, generando movimientos de defensa que, a simple vista, se confunden con ataques. Palabras clave Mantis Canibalismo Sexual Toma de decisiones ABSTRACT SEXUAL SELECTION IN MANTIS (PARASTAGMATOPTERA TESELLATA): EFFECTS OF FEMALE AGGRESSIVENESS ON MALE MATE CHOICE Recent research has proposed that male mantis (Parastagmatoptera tessellata) are not complicit in cannibalism and that they are able to avoid females under conditions that favors cannibalism (i.e. starvation). On these bases, we investigate whether males are sensitive to the level of aggression exhibited by females. To that end, twenty males were confronted individually with two choices: a) a female exhibiting strikes (“aggressive female”) when a harnessed male is placing close to it, and b) a female who do not exhibit strikes (“passive female”) when the same male is placing close to it. Preliminary results indicate that male behavior changes according to the number of strikes exhibited by females. When the “aggressive” females performed just a few strikes (=6) the “passive” females were preferred. On the other hand, the “aggressive” females were preferred when they exhibited many strikes (>6). A possible explanation is that aggressive females were chosen when they exhibited many strikes (>6) due to a phenomenon of enhancement (when females strike, they move markedly and this could have driven male’s attention to them). Thus, just a few strikes (=6) would be an effective stimulus, avoiding any enhancement of females. To test this interpretation additional experiments are in progress. Key words Mantis Sexual Cannibalism Decisionmaking