It is now known that tubular accumulations can sometimes be detected in the cell cytoplasm. These tubular aggregates are known by a variety of names including ‘parallel tubular arrays’ and ‘crystalloid endoplasmic reticulum’. Tubular aggregates can display a variety of morphological forms and are thought to be derived from the endoplasmic reticulum. The occurrence of tubular aggregates has been linked to a number of conditions including muscle disease and neoplasia but the precise role of tubular aggregates is not well understood. This study used thin section electron microscopy to document the presence of tubular aggregates in an insect cell line (C6/36 cells derived from Aedes albopictus) following inoculation of the cells with material derived from cell culture passaged homogenized Culex australicus mosquitoes. The tubular aggregates were detected in about 2% of treated cells and had three morphological forms which were termed primary, secondary and tertiary, with progressively greater levels of structural complexity. The findings indicate tubular aggregates can be induced in an insect cell culture system by an unidentified agent, possibly a virus, present in some mosquitoes.