Sexual dimorphism of locomotory organs appears to be common in a variety of arthropods, however, the underlying evolutionary mechanisms remain poorly understood and may be the consequence of natural or sexual selection, or a combination of both. I analyzed the activity pattern of seven cohorts of a wolf spider, Venatrix lapidosa, over four consecutive years. Males appear to be the more active sex in search for a mate as they show temporarily higher activity prior to the periods of female brood care. Morphometric data on leg length showed comparatively longer legs for males than females. Allometric leg elongation in all four legs of males arises only after the final molt suggesting its significance in reproductive behavior such as mate search. A comparative analysis of two Australasian wolf spider genera with different activity profile of females, Venatrix (sedentary females) and Artoria (vagrant females) provides further evidence that limb elongation in males mainly arises due to indirect male mate competition.