SCANNING ELECTRON-MICROSCOPY OF CEPHALIC REGIONS OF HETERODERA-GLYCINES AND 3 RELATED CYST-NEMATODE SPECIES

Cephalic regions of second-stage juveniles and white females of the fo ur closely related species, Heterodera glycines races 1-5, H. lespedez ae, H. schachtii, and H. trifolii, were examined by scanning electron microscopy. Interspecific and intraspecific variation occurred among t he populations, but differences among female cephalic regions could no t be used in species identification of the populations studied. Differ ences in morphology of dorsal and Ventral lips and partial head annula tion in second-stage juveniles of H. lespedezae, H. schachtii, and H. trifolii may aid in species identification but cannot be used as the s ole criteria to identify the species evaluated in this study.