Population Dynamics of Bothriocephalus rarus (Cestoda) in Notophthalmus viridescens

Abstract

The population dynamics of Bothriocephalus rarus, a cestode parasite of the red-spotted newt, Notophthalmus viridescens, were studied in an artificial pond in Ritchie Co., West Virginia, for over 1 year. The probability of a B. rairus egg surviving to the procercoid stage was 0.022 (2.2%). The probability of procercoid survival to the juvenile worm stage in adult newts was 0.038 (3.8%) (based on the natural recruitment rate); the probability of procercoid survival to juvenile worms in larval newts was 0.029 (2.9%). Life table equations suggest that adult newts, feeding on infected copepods and larval newts, are the major source of worm recruitment into the infrapopulation of worms in the pond. Infected larval newts contribute replacements for worm mortality in the adult newt population when they return to the pond from 2-7 years later as infected adults, and infected efts serve as a reservoir for the parasite and act as a deterrent to worm extinction from the pond as well as a means of parasite dispersal to a new pond.