Post-Infection Development of Heterodera lespedezae

Morphological changes occurring during post-infection development and the influence of temperature on the life cycle of Heterodera lespedezae are reported. Morphological development was similar to that of H. schachtii. Each post-infection stage had a distinct styler, and fed actively. Detailed observations were made of cuticle formation and markings, esophageal glands, and reproductive system. Certain developmental phases, such as matrix deposition and oviposition, appeared to be correlated with color changes of the adult female body. The effect of temperature on nematode development was observed in a phytotron at day/night temperatures of 18/14, 18/18, 22/18, 26/22, 26/26, and 30/26 C; the optimum was 26/26 C. More time was required to complete the life cycle at the three lower temperatures than at the three higher temperatures.