Pigment granules in the tegumental yellow strips of social wasps: a scanning electron microscopic study.

In social wasps the yellow pigment assumes the shape of quasi-cylindrical granules 0.6...0.8 microm long and 0.3...0.4 microm in diameter. These are mostly concentrated around the bases of the funnel-like cuticular sheath containing the cellular elements of the sense organ. Feeding colchicine to the wasps induces degeneration of the granules but the addition of xanthines to their diet render them refractory to the destructive action of colchicine. Changes in the size and shape of the granules with age and following continuous illumination are described.