The courtship and mating costs of limb loss in the wolf spider Pardosa milvina (Araneae: Lycosidae).
Males of the wolf spider, Pardosa milvina, actively wave their first pair of legs during courtship of females. Limb loss is extremely common among adult P. milvina but appears to be more common among adult males than females. Field surveys indicate that 30% of all adult male P. milvina wolf spiders have missing limbs (N = 296) compared to 21% for females (N = 353). A large percentage of males were also missing multiple limbs. We investigated the effect of limb loss on courtship and mating behavior in P. milvina. Virgin males were randomly divided into five treatments: 1)left 1st leg removed (N=25/treatment),2)right first leg removed, 3)both left and right first legs removed, 4) both the first and second pair of legs removed, or 5) intact males. We then paired each male with a randomly selected virgin female. We recorded time to initiate courtship, courtship duration, time spent mounted on the female, mounting success, and courtship intensity as measured by leg waves/min, body shakes/min, or pedipalp raises. We also measured female lunge responses toward male, and the number of leg taps by females. Data suggests missing 1-2 legs does not significantly reduce a male's ability to mate, while missing four legs is detrimental to mating success and increases female aggression. These four-legged spiders do not display leg waves, and have a lower overall rate of displays/sec than males in other treatments. Four-legged males also had significantly shorter copulation time than any other treatment group. We conclude that adult male spiders can incur limited leg loss with no measurable reproductive cost