Strict monandry is rare in animals in nature. Though traumatic mating has been reported to postpone female re-mating, it rarely leads to strict monandry. We demonstrate that traumatic mating causes strict monandry in a wandering wolf spider, Pardosa pseudoannulata. We show direct evidence that males damaged the inner walls of female genital tracts with the sharp embolus on their palps during insemination. To confirm that the trauma reduced female willingness to re-mate, we mimicked male palp insertions by micro-injecting seminal fluids and/or causing trauma to female genital tracts, then we let the manipulated females mate. Result of mating trials showed that seminal fluids indeed have, but not significant impact in inhibiting female mating. However, once female genital tracts were wounded, female’s mating willingness were greatly suppressed. In addition, we found that wounds caused by male traumatic matings lead to hemorrhages, which gradually turn into impermeable amorphous mating plugs. The mating plugs gradually blocked female genital tracts, and finally completely preventing females from re-mating. We thus provide evidence for strict monandry in P. pseudoannulata due to male traumatic mating through two means: genital trauma suppressed female’s re-mating willingness and mating plugs completely prevented females from re-mating.

Mating trials, GC-MS, HPLC