Der Fremdling im Therapiegarten – Cis chinensis (Coleoptera, Ciidae) und sein Umfeld

Samples of the tree fungus Antrodia xantha were collected on Pinus strobus in the therapy garden of the UPK campus (University Psychiatric Clinics) in Basel in summer 2021. The samples contained an alien Ciidae species new to Switzerland: Cis chinensis Lawrence, 1991, a species otherwise mainly known as a storage pest of commercially dried fungi. The adults and larvae of the Basel population are described and illustrated. When comparing the size of the adults of the two sample series collected two weeks apart, statistically significant differences were found. It appears that the above-average temperatures in June 2021 favoured the size of the second group. A number of (4–)5 larval stages are postulated for larval development. As an endoparasitoid of the eggs of C. chinensis, an unknown Mymaridae of the genus Cleruchus was found. Noteworthy was an unusually heavy infestation of Ciidae by phoretic mites (Histiostomatidae). During follow-up surveys in early 2022, additional individuals of C. chinensis were also found on the fruitbodies of other fungi growing in the immediate vicinity of the site where the population of the species was initially observed on A. xantha. A list of all Ciidae detected on the UPK campus is provided, and the spectrum of host-fungi of C. chinensis is discussed.