Intraspecific morphological variation among populations of Pratylenchus brachyurus and P. coffeae.

Three populations of Pratylenchus coffeae and two of P. brachyurus, each originating from a single female, were maintained on Citrus spp. or Solanum nigrum L. for several years under greenhouse conditions. Nematodes were extracted from roots, and adult female specimens were killed, fixed, and mounted in glycerine for microscopic study. Variables measured were distance between vulva and anus and lengths of the stylet, posterior uterine sac, and tail. The mean data and coefficients of variability suggest that styler length had the least variability, and length of posterior uterine sac the most. When males and distinct spermathecae are not evident in P. coffeae populations, the species can he distinguished from P. brachyurus by a shorter mean stylet length, longer mean posterior uterine sac length, and much longer distance between the vulva and anus.