The stag beetle is an insect of the family Lucanidae, which belongs to the order Coleoptera. With its considerable dimensions (the male reaches a length of 10 cm, including the large mandibles), it is the largest Coleoptera in Europe. It lives in the cavities of tree trunks, with a particular preference for oaks.
In males, there are different shapes and sizes of mandibles. Those with the smaller appendages are called PRIONODONT, the middle ones MESODONT, and the larger ones TELODONT.
Many factors contribute to the size of the adult, such as the type of wood the larva feeds on during its development, the amount of food available, and the seasonal conditions during the developmental stages. It can take up to 5 years for the larva to pupate before it reaches maturity which will last only a few months, the time necessary to reproduce.
The rare TELODONT males, whose mandibles are out of proportion with the rest of the body, have difficulties moving and performing stable flights. These organisms consist almost entirely of insects, a large proportion of which belong to the order Coleoptera. Their peculiarity is that they feed on dead wood, thus promoting plant decomposition. These insects play a fundamental role in the ecological cycle that regulates the forest system and its renewal.
In the case of Lucanus cervus, rotting wood gets digested by symbiotic bacteria that reside in the larval digestive tract. . The undigested material returns to the environment and promotes the growth and development of generations of plants and trees in the understory, ensuring the proper functioning of the forest ecosystem. This is important because a healthy understory is fundamental for the preservation of the surrounding environment and can fight phenomena such as desertification or hydrogeological instability (a widespread problem in Italy with significant socio-economic implications).