Chrysolina cerealis (Linnaeus, 1767) 

The only member of the subgenus Chrysomorpha Motschulsky, 1860, this is a very widespread Palaearctic and Asian species occurring as five distinct subspecies:

• C. c. cyaneoaurata (Motschulsky, 1860) from Siberia and Mongolia,

• C .c. megerlei (Fabricius, 1801) from Central and Southeast Europe,

• C. c. mixta (Kuster, 1844) from the European Alps and the Pyrenees and

• C. c. rufolineata (Motschulsky, 1860) from European Russia, Crimea and Ukraine.

• The typical subspecies, C. c. cerealis s.str. occurs in western, central and northern Europe including the U.K.

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On the continent the typical habitat is forests, open woodland, meadows and mountain grassland above 600m. where it has been recorded from a range of Lamiaceae including mints, calamint, winter savory, and thyme. It has been recorded up to 1800m in the Pyrenees. In the U.K. it is a very local species with modern records from two sites in Wales; Snowdon and Cwm Idwal (Caernarvon), both of which are National Nature Reserves, although it has not been seen at the latter since 1980. The Snowdon population (estimated at around 1000 adults) may be in decline or it may always have been rare. Adults are active from April until October in mountain grassland where the host plant, wild thyme, occurs; both adults and larvae feed upon the leaves and, preferentially, the flowers. The eggs are laid towards the tips of grass stems near the host during June and larval development is rapid with pupation occurring during August in an underground cell near the base of the host. At least some adults usually eclose during the summer, and these will overwinter but it is thought that the main overwintering stage is the fully grown larva. The U.K. population is thought to be genetically distinct and is protected under schedule five of the Wildlife and Countryside Act, 1981.