Tissue Culture of the Rice Stem Borer, Chilo suppressalis WALKER (Lepidoptera : Pyralidae) : II Morphology and in Vitro Cultivation of Hemocytes

Abstract

The blood of Chilo suppressalis larvae was found to contain 7 types of hemocytes, namely, prohemocytes, plasmatocytes, granular hemocytes, spherule cells, oenocytoids, podocytes, and vermiform cells. Primary cultures of the hemocytes were successfully maintained for over 12 months by changing the medium once a week. Prohemocytes and plasmatocytes multiplied by mitoses, whereas other types of hemocytes did not survive for long in the primary cultures. Subculturing of cells was tried from primary cultures by taking parts of the cell colonies 7 months after the culture was set up. Subcultured cells multiplied by mitoses and survived for over 5 months. The plasmatocytes usually formed cell sheets. The prohemocytes were often found on the plasmatocyte cell sheets. The prohemocytes aggregated to form cell masses or they suspended themselves freely in the medium. During the cultivation, morphological changes of the cells, which suggested the transformation of prohemocytes into plasmatocytes, were observed.