Growth, egg production, and population density of the spider, Nephila clavata in relation to food conditions in the field

Summary Field studies were carried out to clarify the growth pattern, egg production and changes in the population density of the spider, Nephila clavata, in relation to food conditions. Larger individuals, which might have consumed more amount of food, became gravid earlier (early October), but even smaller ones also became gravid by early November. The difference of body size in mature females was greater than those reported in other species. The rate of growth and the fecundity were greater in the plot where food was more abundant, and the number of individuals in the early part of the development period in the following year was also greater in that plot. Although the population densities in the early part of the development period differed considerably between the two study plots, the difference became obscure after September when almost all spiders had matured. This suggests that the number of adult individuals had little relation to that of juveniles.