Re-description of Togwoteeus biceps (Arachnida, Opiliones, Sclerosomatidae) with notes on its morphology, karyology and phenology.

Abstract

The harvestman genus Togwoteeus Roewer 1952 is monotypic. Its only species, T. biceps (Thorell 1877), is known from throughout western Canada and USA and is newly recorded from California, Nebraska, Nevada, Oregon, South Dakota, and Utah. This species occurs below 500 m and at the highest elevation (4100 m) of any recorded harvestman in North America. It ranges from about 33-54° N and exhibits considerable variation in its morphological measurements. Twenty-seven such measurements are summarized for 80 males and 74 females. Ultrastructural details of the integument, appendages and genital organs are presented. The karyotype is 2n = 22 for both sexes. All chromosomes are metacentric and obvious sex chromosomes were not detected. Immature T. biceps overwinter and reach adulthood in late spring or early summer. Adults die by late fall.