Newly developed fungal diet for artificial rearing of the endangered long‐horned beetle Callipogon relictus (Coleoptera: Cerambycidae)

In this study, we attempted to develop an artificial diet to effectively rear the endangered long‐horned beetle Callipogon relictus Semenov to facilitate restoration efforts for this species. Fungal mycelia of the white‐rot fungus Pleurotus florida (Eager) were, for the first time, provided as an artificial diet for the larvae of C. relictus. The experiment started on August 11, 2015 with 53 larvae being provisioned with the fungal diet under laboratory conditions (25°C, 60 % RH, L:D 0:24) without diapause. During the first year, 11 adults (4 males and 7 females, 20.8 % of the 53 larvae) emerged between September 10 and October 1, 2016. The body length of the largest male was 106.8 mm, and three of the four males exceeded 100 mm in length. These results show that a fungal diet for rearing C. relictus is useful not only for reducing the larval period to approximately 1/6 of the normal larval period in nature, but also for producing large adults. These results support the notion that fungus may provide nutritional benefits during the larval development of C. relictus, and also indicate that this species is fungivorous.