New Insight Into the Evolutionary Arms Race Between Spider Egg Sac Pseudoparasitoids and Active Maternal Care by the Spiders

  New Insight Into the Evolutionary Arms Race Between Spider Egg Sac Pseudoparasitoids and Active Maternal Care by the Spiders ABSTRACT Pseudoparasitoids can lead to high mortality in spider egg sacs, and in some cases, they reduce the reproductive success of a spider female to zero. On the other hand, a species that develops within the spider's egg sac uses a limited resource derived from a single egg sac for its larval development. Therefore, the most crucial behaviour that increases the fitness of free-living pseudoparasitoid females is choosing the best host for their offspring. We analysed various points of the counter-adaptations of the spider egg sac pseudoparasitoid and spiders exhibiting active maternal care, utilising the ichneumonid  Hidryta fusiventris  (Thomson, 1873) and the wolf spider  Pardosa lugubris  (Walckenaer, 1802). We showed that the oviposition decision of  H. fusiventris  is based on the spider's egg sac size and that the fema...

From burrows to spotlight: first description of the female of Eresus lavrosii Mcheidze, 1997 (Araneae, Eresidae), with notes on the natural history

 


From burrows to spotlight: first description of the female of Eresus lavrosii Mcheidze, 1997 (Araneae, Eresidae), with notes on the natural history

Abstract

Eresidae (velvet spiders) is a relatively small family of spiders, most-diversified in the African continent. The present study provides the first description of the female of Eresus lavrosii Mcheidze, 1997, which has remained undiscovered for over two decades. We also briefly review the species’ history and add knowledge of its ecology, biology, and distribution. Diagnostic drawings and digital photographs of female and male copulatory organs, alongside COI barcoding results, photographs of live and preserved specimens, and of microhabitat are also presented.

Seropian A, Bulbulashvili N, Makharadze G, Kovács G (2025) From burrows to spotlight: first description of the female of Eresus lavrosii Mcheidze, 1997 (Araneae, Eresidae), with notes on the natural history. Caucasiana 4: 1-14. https://doi.org/10.3897/caucasiana.4.e151922