STUDING THE DEVELOPMENT AND STAGE DESCRIPTION OF CITRUS NEMATODE Tylenchulus semipenetrans (MEDITERRANEAN RACE) ON SOUR ORANGE AND LEMON

Abstract

The results indicated that the citrus nematode (Mediterranean race) completed it’s life cycle in about 7 and 8 weeks on the root of the lemon and sour orange respectively ٫ the number of nematode stages parasitized on lemon roots or extracted from it’s soil were higher than that of sour orange. Second stage juveniles parasitized on lemon and sour orange roots did not differ significantly in the value of parameters including the thickness of the cuticle٫length of stylet ٫ width of the basal bulb in addition to values of b and c٫ while they differed significantly in the length and width of the body٫ length of esophagus and posterior part of the body with the highest value recorded in the juveniles parasitized on lemon except (a) value recorded for juveniles parasitized on sour orange which was the highest. Concerning the males٫ no significant differences were recorded between them in most parameters including values of body width٫ thickness of cuticle and length of stylet ٫esophagus and spicules in addition to values of b and c.while the males extracted from the soil planted with lemon showed higher values in length of the body and length of the posterior part of the body٫but higher value of (a) was found in males extracted from soil planted with sour orange. Mature females parasitized on lemon were significantly bigger than those parasitized on sour orange because the higher value of body width٫neck length٫body width at vulva٫ post vulval section length and post vulval section width but did not differ significantly in the thickness of cuticle. Size of egg masses and number of eggs formed by females parasitized on lemon were significantly bigger than those formed by females parasitized on sour orange with no differences in egg size.