Herpetomonas ludwigi (Kramář, 1950) n.comb., the trypanosomatid parasite of cranefly larvae (Diptera, Tipulidae)

Abstract

1. Herpetomonas ludwigi was found in 5–6% of larvae of Tipula paludosa in two out of three populations examined.2. The developmental cycle is confined to the enteric caeca of the host. From a study of smears and sections of these organs it was concluded that the life cycle was composed of the following stages:(a) A long-flagellated leptomonad stage which is short-lived and probably represents the form in which the flagellate enters the caeca from the mid-gut lumen; (b) a haptomonad or attached form in which the flagellum is short or absent: this probably represents the growth phase of the organism; (c) a crithidial phase which arises by a series of divisions from the haptomonad; (d) a small trypaniform stage which breaks free and lives in the lumen of the caecum; (e) a precystic flagellate; and (f) a small, thick-walled cyst.3. This species is characterized by its restriction to the enteric caeca and the short duration of free swimming as opposed to attached stages in the life history. This second feature is a corollary of the first. The periodic contraction of the enteric caeca makes attachment obligatory throughout the growth and division stages. These contractions also serve to void cysts into the mid-gut whence they leave the larva with its dejecta to infect other larvae.