D3347: Experimental life history study for the endangered saproxylic giant longhorn beetle Callipogon relictus: Restoration insights with a five-year monitoring

Callipogon relictus is the largest beetle in the palaeactic region and only representative of the otherwise exclusively Neotropical genus Callipogon Audinet-Serville, 1832. It is listed in the red data book both in Russia and South Korea. However, the true life cycle of the endangered C. relictus in nature was hitherto unknown to us. In order to release artificially grown Callipogon beetles into the wild in the near future for the purpose of restoration, precise ecological information about its life history in the field must be experimentally understood in advance. In 2017, a large steel cage was created for this and a timber of dead Populus deltoides installed as the host tree in order to let a pre-mated female lay eggs on it. By 2022, the results showed that 1) the minimum larval period of C. relictus in nature is three years, 2) the average larval development is likely to be four years, and 3) some individuals spend their larval stage inside the trunk for five years.