You can find some information in Bienkowski http://link.springer.com/article/10.1134/S0013873811050095
For Latvia, please use the following publication on RG: https://www.researchgate.net/publication/216273064_On_Latvian_Chrysomelinae_Coleoptera_Chrysomelidae_4_Genus_Chrysolina_Motschulsky_1860
Article On Latvian Chrysomelinae (Coleoptera: Chrysomelidae): 4. Gen...
Thanks Dmitry, the fact that Artemisia can be a host plant is a new fact for me!
I know there is a paper about that species, but I unfortunately I could not get a copy by now:
Buse, A. (1993). Life-cycle and behaviour of the British population of Chrysolina cerealis (Coleoptera: Chrysomelidae): the implications for survival. Entomologist, 112: 105-117.