Walking through parks and gardens during the summer and in the first days of autumn it is easy to note, in points exposed to the sun, a red and black insect. It is Pyrrhocoris apterusthe Cimice carabiniere or Rossoneri bedbugso called for the colors that characterize it. It is absolutely harmless to humans and does not cause damage to animals or plants. However, it is extremely disgusting for birds or other predators, but warns them thanks to the evident coloring with Red and black contrast geometric designsdanger signal for any enemies, an example of aposthematical coloring, used by many animals to report potential toxicity.
The Rossoneri bedbug must be an important scientific contribution in the field of genetics: it was in fact decisive for the discovery of the X chromosome. Observing the cell division of its sexual cells, the German biologist Hermann Henking noticed a unknown chromosome (for this reason defined x) that did not behave like the others and was not divided. Only after a few years, do you find that it had a role in determining sex in different animal species.
The main characteristics of the Rossoneri bedbug, or cimice carabiniere
Pyrrhocoris apterus, He is a family emitter Pyrrocorid which has about 400 species in the world. The very name of the genre to which it belongs, Pyrrhocorisprovides a clear indication on the appearance of the insect: it derives, in fact, from the Greek “pyrrhos” (fiery red) and means sparkling insect or red.
The species is very common And it has wide diffusion in Europe, Asia and North Africa. It can be confused, for a not very attentive eye, with the Mediterranean red bedroom (SCANTIUS AEGYPTIUS) and with the bug of cinnamon (Corizus Hyospryami) which belong to other families and present equal colors, but different geometries dorsal drawings.
These are phytophagous insects, that is, they feed on plants and, like all bedbugs, have a “pungent-sucking” mug apparatus, with jaws and jaws transformed into long and thin stilets capable of piercing vegetable fabrics for extract the sap. Mainly feed on the nafebody lymph, plane tree, carpine and linden and sometimes they also suck theEmolinfa (the liquid that in insects has the same function as our blood) of dead insects. However, they are not harmful to plants and are harmless to man.
Adults, no longer large of 1 cm in length, live forming rather numerous groups especially in sunny places. They mate in spring and very often they remain in mating for a few days: With this strategy, individual males ensure themselves reproductive success.
The neanids (the youth stadiums of the insect) are quite similar to adults but of lower size and with mainly red color; When they are in groups they issue a rather nauseating smelluseful repellent against natural predators. In the late autumn, with the variation of lighting during the day (photoperiod) and, above all, with the lowering of temperatures, the rossoner bedbugs enter into diapause taking refuge in the cracks of the wood or walls, under the bark or under the stones.
The cimice carabiniere and the discovery of the X chromosome
Precisely because the Rossoneri bedbug is very common and abundant, completely harmless and easy to breed it has also become a “laboratory animal“, widely used for different experiments and which has made it the protagonist of a curious correlation with the history of genetics.
The history of the cimice carabiniere and the X chromosome begins in the 1891 When the German biologist Hermann Henking was studying the phenomenon of meiosis in the spermocytes of the Pyrrhocoris apteruslarge enough to be able to observe the chromosomes under a microscope. During his studies he noticed that a chromosome behaved differently than all the others: during the meiotic cell division All the couples of chromosomes separated except one! This rebellious chromosome had a different conformation from the others and, moreover, it was present only in some cells, while others was absent: thus, some spermocytes had 12 chromosomes and 11 others. For this peculiarity it was indicated with the X, as an unknown element. In fact, in Pyrrhocoris the X chromosome is the bigger and easier to identify During both meiotic divisions and moves even more slowly than others.
Only many years later, other researchers understood the importance of this chromosome for the Sex determination In man and in many other species, whose name therefore derives from this curious observation of Henking. Subsequently, the other sex chromosome was also discovered which, By analogy with mathematical unknowns, it was called Y To differentiate themselves from all the other chromosomes that by convention are indicated with numbers. The episode, so important from a scientific point of view, also made the unconscious Rossoneri bedbug famous.
