Die Carotinoide und der Gallenfarbstoff der Stabheuschrecke, Carausius morosus und ihre Beteiligung an der Entstehung der Farbmodifikationen

Abstract

The green colour of Carausius morosus is based on five carotenoids and a bile pigment. The pigments were separated by thin-layer chromatography and identified by their R f -values and absorption spectra. The carotenoids are β-carotene, isocryptoxanthin, isozeaxanthin, a trace of lutein, and a red keto-carotenoid, which is not yet identified. The bile pigment is not glaukobilin as assumed till now, but biliverdin. Tettigonia viridissima contains β-carotene, cryptoxanthin, lutein, and four blue bile pigments separable by thin-layer chromatography. Carausius almost selectively takes up β-carotene from the plant. β-Carotene is the major pigment in the fat body. On its way into the epidermis, most of it is converted into isozeaxanthin, which is the major carotenoid of the epidermis. Smaller amounts of β-carotene are converted into isocryptoxanthin and a red keto-carotenoid. The amount of bile pigment in Carausius does not depend on the chlorophyll in the diet. But different coloured individuals, fed on the same diet and grown in various colour and light conditions, differ in their amount of carotenoid and bile pigment. These differences are less than those of ommochromes. The synthesis of biliverdin is enhanced by darkness and low temperature, whereas the uptake of carotenoids is enhanced by warmth and light. Under these conditions the increased uptake of β-carotene is followed by transport into the epidermis and conversion into isozeaxanthin.