Redescription of the spider Robertus arcticus (Chamberlin & Ivie) (Araneae: Theridiidae), with the first description of the female


  • J. Pinzon Canadian Forest Service
  • K. Kent Canadian Forest Service
  • D.J. Buckle None
  • R. Bennett Royal British Columbia Museum


The original description of Robertus arcticus (Chamberlin and Ivie, 1947) (Araneae: Theridiidae) was based on a single male collected in Alaska, United States of America. The female has remained undescribed, although specimens of both sexes have been collected over the intervening decades. The species occurs in boreal Alaska, and records from Cold Lake, Alberta, Canada and James Bay, Ontario, Canada suggest that it is probably widely distributed in the Canadian boreal. Here we redescribe the male and describe the female for the first time. Most specimens examined in our study were collected from the ground of boreal forest peatlands in northeastern Alberta.