Colouring dragonflies due to chemical balance within the pigment cells located on the abdomen of insects. Under the influence of oxidizing agents, these cells become yellow, and the presence of reducing agents, turn red. Took advantage of Japanese scientists who discovered this effect, and the "repainted" yellow young dragonflies in red color characteristic of adults. New data are described in an article published in the publication Proceedings of the National Academy of Sciences.
A group of Japanese biologists led by Ryo Futahasi from the National Institute of Advanced Industrial Science and Technology (AIST) removed the pigments of the abdomen a few dragonflies bright red type Crocothemis servilia, Sympetrum darwinianum and Sympetrum frequens and studied them in detail.
According to the researchers, these kinds of dragonflies coloring is used as a signal of sexual maturity. Futahasi and colleagues compared the chemical composition of all the colors that are in the pigment cells of young adult males, attempt to find a mechanism that affects the color change.
It was found that sexually mature males and females are not ready to mate used the same pigment - ksantommatin - in the cells of red and yellow. Specialists have found that the color of the substance bound to a chemical balance in the dye molecule.
Thus, under the influence of strong oxidants - vosobennosti, sodium nitrite - ksantommatin red to yellow, and the addition of a reducing agent - ascorbic acid - returns the original red color.
The researchers tested their findings in experiments with living dragonflies, introducing small amounts of ascorbic acid in the body of young adult males and females through the abdomen. A few hours later all the dragonflies were bright red color, which confirmed the chemical analysis.
Next, the scientists attempted to perform a similar approach with adult individuals, trying to paint them in yellow with sodium nitrite. Biologists were surprised that the oxidizing agent is only partially influenced by the color change - adult dragonfly got a red-yellow color. But, in addition, the insects did not learn of a strong chemical injection and died at the cellular damage in a short time.