Yoshio Yasuda

Babesia ovataのフタトゲチマダニ・中腸内における発育

Studies were made on the development of Babesia ovata in the midgut of the nymphal tick vector, Haemaphysalis longicornis. In 12 hr post-repletion, merozoites were observed outside of erythrocytes infected with B. ovata in the contents of the midgut of the tick. After that, these merozoites were transformed into ring-forms which were comparatively large ring 2-3 microns in diameter. Within 48-72 hr post-repletion, ring-form protozoa developed into spherical form 4-5 microns in diameter. Within 3-4 days post-repletion, fission-forms were transformed into fission-bodies 2-3 microns in diameter. Within 4-6 days post-repletion, fission-bodies developed into bizarre-forms 6-7 microns in diameter. At this time, elongated form protozoa which were considered as microgametes, 6-8 microns in length, are also seen. Within 6-8 days post-repletion, round-formed protozoa which were considered as zygotes in 9-10 microns in diameter were observed in the gut. About 10 days after repletion, those round-formed protozoa were transformed into vermicule-formed and round-formed protozoa, 13-15 microns in length, appeared again in the gut epithelial cells.

Development of Theileria sergenti in the haemolymph of the tick, Haemaphysalis longicornis.

The haemolymph of adult tick Haemaphysalis longicornis infected with Theileria sergenti, was examined at regulat intervals of time. As a result, kinetics could be detected in the haemolymph for the first time 25 days after the engorgement. The kinetics detected could be classified into three types on the basis of their morphological characteristics. They increased gradually in number, reaching a maximum 32 days later. Then they tended to decrease in number, disappearing almost completely from the haemolymph 44 days after the engorgement of ticks.