Quantitative variations in the pteridines during the post-embryonic development of Dysdercus species (Heteroptera: Pyrrhocoridae)

Abstract

Pteridine compounds were extracted from several Dysdercus species and their mutants which differ in yellow and red pigmentation, separated by chromatography, and quantitatively analysed by means of extinction measurement and in situ fluorometry. The erythropterin content was determined in older nymphs and adults of D. cardinalis, D. cardinalis mutant, D. intermedius, D. nigrofasciatus and D. nigrofasciatus mutant, eggs of various ages and nymphs of the 1st instar of D. intermedius and nymphs of the 5th instar of D. nigrofasciatus. Correlations were found between externally visible pigmentation and the content of erythropterin. Yellow eggs and 1st instar nymphs contained less erythropterin than the older red first instar nymphs; yellow and orange mutants less than the red wild-form. The highest erythropterin concentration was found in the deep red-coloured nymphs and adults of D. nigrofasciatus concerning the older developmental stages. The changes of the erythropterin content progressed similarly in the various species either with (yellow type: D. nigrofasciatus) or without (red type: D. cardinalis and D. intermedius) visible change in the colouration. The former was characterized by a change of colouration from red to yellow in the 5th nymph instar. Male fifth instar nymphs contained a little more erythropterin than females. Leucopterin and isoxanthopterin was quantitatively determined in D. intermedius and D. nigrofasciatus (both wild-form and mutant). In both species, both pterins increased considerably and steadily during the 1st larval stage. Higher values were always measured in D. nigrofasciatus. Contrary to the case of isoxanthopterin, leucopterin content of the two species differed in the further stages of development. In D. intermedius, the leucopterin content was low with very little variability. In D. nigrofasciatus mutant the concentration of both pterins was higher than in the wild-form during the whole nymphal development. A decrease in erythropterin was often related to an increase in leucopterin.