Electron-microscopic studies on hemocytes of the Egyptian cottonworm, Spodoptera littoralis (Boisduval) infected with a nuclear-polyhedrosis virus, as compared to noninfected hemocytes : II. Virus-infected hemocytes

• Published in: Journal of invertebrate pathology Vol. 14; no. 2; pp. 245 - 257
• Main Authors: Kislev, Naomi, Harpaz, I., Zelcer, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 1969
• ISSN: 0022-2011; 1096-0805
• DOI: 10.1016/0022-2011(69)90111-6

Ultrathin sections of hemocytes, extracted from Spodoptera littoralis caterpillars infected with a nuclear polyhedrosis, showed the virus particles in situ to be rodshaped, measuring 295 × 30 mμ on the average, and surrounded by an intimate membrane. The virus particles seen in infected nuclei are either single or grouped in bundles enveloped in a double-layered membrane which is often corrugated. At a more advanced stage of infection the virus bundles and the single particles become occluded together within polyhedral inclusion bodies, measuring 1–3 μ with 1.8 μ as an average. Of the four major types of hemocytes differentiated in the blood of this insect, virus formation was found to take place mainly in the plasmatocytoids, and only to a much lesser extent in the granular hemocytes and oenocytoids. Adipohemocytes were never seen to sustain virus development. Plasmatocytoids were observed phagocytosing free virus particles as well as several whole polyhedra. Virus particles, originating presumably from the nucleus of the cell, were found also in cytoplasmic extensions of infected plasmatocytoids.