Experimental Infection of Various Latex Plants of the Family Asclepiadaceae with Phytomonas elmassiani

SYNOPSIS. Trypanosomatid‐free plants of the family Asclepiadaceae identified as Asclepias syriaca, A. curassavica, A. incarnata, Stephanotis floribunda, Seutera maritima, Amphistelma scoparia and plants of the family Euphorbiaceae identified as Euphorbia tirucalli, E. trigona, and Pedilanthus tithymaloides were exposed to the bite of the bug, Oncopeltus fasciatus, infected with Phytomonas elmassiani, a flagellate which occurs naturally in A. syriaca and O. fasciatus. Two weeks subsequent to exposure to laboratory‐infected oncopeltids all the experimental Asclepiadaceae were infected. The mean length of the protozoa varied depending on the host plant. The flagellates in A. syriaca, A. curassavica, and A. incarnata were shorter than those in S. floribunda, S. maritima, and A. scoparia.None of the Euphorbiaceae became infected.