A SECOND CYST-FORMING NEMATODE PARASITE OF BARLEY (HORDEUM VULGARE L. VAR. ESMERALDA) FROM MEXICO

Abstract

Cid del Prado, V. I. and B. L. Miranda. 2008. A second cyst- forming nematode parasite of barley (Hordeum vulagre L. var. Emeralda) from Mexico. Nematropica 38:105-114. A new species of cyst nematode, Cactodera rosae n.sp., is described and illustrated from specimens obtained from roots of barley, Hordeum vulgare L. variety Esmeralda, and associated soil, from San Juan Ixtilmaco, Apan Hidalgo State. Cactodera rosae n.sp. cysts are characterized by their lemon shape, dark brown to black color, 460-840 um length, with a length / width ratio of 1.2-2.1, strongly striated pattern on the cuticle, a prominent vulval cone with circumfenestrate vulva, and an anus located 25-60 um from the fenestra in a depression in the cuticle. Egg surfaces bear conspicuous punctations. The second stage juvenile is characterized by the presence of 4-5 lip annulations on the head, a strong stylet 16-26 um long with rounded stylet knobs, a tail 31-68 um long and 6-14 um wide with a hyaline portion of 11.2-28 um in length, and lateral fields with four incisures and incomplete areolation. A key to the species of Cactodera is presented.