Life history of Pardosa moesta and Pardosa mackenziana (araneae, lycosidae) in central Alberta, Canada

The density, fecundity, and Life-cycle of Pardosa moesta Banks 1892 and Pardosa mackenziana (Keyserling 1877) were studied in a deciduous forest in central Alberta, Canada. Density estimates were lower than reported for other Pardosa species; they ranged from 0.46 per m(2) for male P. mackenziana to 2.99 per m(2) for immature P. mackenziana. Adult female densities were below 1 per m(2) for both species. Clutch sizes were highly variable and averaged (+/- SE) 33.06 +/- 1.29 for P. moesta and 48.37 +/- 1.67 for P. mackenziana. Although clutch size was positively related to female size, little of the variation was adequately explained by female size alone. Several lines of evidence suggest that P. moesta and P. mackenziana require two years to mature in central Alberta, with a peak reproductive period in May and June. Females carry egg sacs into the summer months and immature spiders overwinter following the first growing season when they are still less than 5 mg in weight. After a second summer of growth, subadults overwinter and maturation occurs early in the spring.