Chrysolina fastuosa

Chrysolina fastuosa, also known as the dead-nettle leaf beetle, is a species of leaf beetle in the family Chrysomelidae found in Europe, Caucasus and northern Turkey.

Description
The species has a length ranging from 5.1 - 6.9 mm. C. fastuosa has a gold shine that transitions to a green or violet-blue longitudinal stripe near the shoulder band of the elytra as well as near the suture. Occasionally, specimen of C. fastuosa may be completely green or black in colour.

Ecology
Adults and larvae of C. fastuosa feed on various plants in the family Lamiaceae, including hemp-nettle (Galeopsis) and dead-nettle (Lamium). It is also known from common nettle (Urtica dioica), which is in family Urticaceae. Adults and larvae graze on leaves, while larvae may also be found in fruiting calyxes.

Larvae are parasitised by the tachinid fly Macquartia grisea.

Taxonomy
In the genus Chrysolina, C. fastuosa is classified as the only member of the monotypic subgenus Fastuolina, proposed by Warchałowski in 1991. Some authors consider the name "Fastuolina" to be an unavailable name under the International Code of Zoological Nomenclature, so the new name Fasta was proposed for the subgenus by Petitpierre and Alonso-Zarazaga in 2019.

In 2023, a phylogenetic study based on DNA extracted from museum specimens found that C. fastuosa is sister to the genus Oreina. The authors of the study therefore raised the rank of Fasta from subgenus to genus, resulting in the new combination Fasta fastuosa for the species.