Ixodes signatus nymphs were subjected to the scanning electron microscopy for the observation of the major physiological sense organs including Haller's organ. Funger prints and variable sensory setae were found on the body surface, and especially well developed setae were identified on the article IV and on the anal lobes. A central button-like organelle and numerous small holes were found in the spiracular plate. The Haller's organ was identified at the distal point of the tarsus I and regarded as the major sensory organ, chemoreceptor. Two types of sensory setae were observed, the shorter ones in front of the organ and the longer ones in distal front as well as behind the organ. The fully opened organ was ellipsoidal and a total of seven basiconic sensory pegs rooted deeply and shaped like well arranged hooks were found inside the organ

Twenty-eight porcine rotavirus were isolated from piglets with diarrhoea in Chonnam Province. According to the age, 41 to 60 day old pigs showed the highest isolation frequency among the post weaning pigs. The characteristics of the field isolates were determined by electronmicroscopy(EM), immunofluorescent assay(FA), and electrophoretic migration patterns of the genome profiles. Some of the isolates showed remarkable haemagglutination activity against rabbit and dog erythrocytes, ranging from 4 to 2848, respectively. At least 3 serotypes of porcine rotavirus were recognized by serum neutralization test using serotype specific rotavirus hyperimmune sera

In the course of studying porcine enterovirus infection in piglets, the vascular endothelial cells in the CNS of colostrum-deprived piglets with polioence-phalomyelitis were investigated by electron microscope. The experimental piglets were orally infected with the porcine enterovirus serogroup 3 isolated in Korea and necropsied at 7 days postinoculation. Crystalline arrays of viral particles were found in the vascular endothelial cells of the spinal cord and cerebellum. Aggregates of immature viral particles were occasionally observed in the vascular endothelial cells in the meninges. The rough ER was deprived of ribosomes, irregularly dilated and associated with viral crystals. There were abundant cytoplasmic filaments, dilatation of perivascular space, perivascular cuffing, and the partial disruptions of endothelial cell membrane and basal lamina