Fecundity and fertility in Latrodectus hasselti (Araneae: Theridiidae)

A total of 216 egg sacs of Latrodectus hasselti Thorell was examined to determine the proportion of infertile or otherwise inviable eggs. This proportion varied greatly between egg sacs but there was no consistent trend towards an increase or decrease in fecundity or fertility in sequences of egg sacs produced by given female spiders. It is suggested that the production of inviable eggs, by providing an early food source, may enable spiderlings to escape from unfavourable areas.