Chrysolina marginata (Linnaeus, 1758)       Notable A
   At some time in the past this species has been very widely distributed with many pre 1970 records from West Sussex to as far north as Inverness and Orkney, but with records from only five vice-counties since 1970 it is now considered to be 'possibly declining' (Hyman and Parsons ¹). It must be admitted though that this is not the easiest species to find; our only encounter was after midnight when a single specimen was found crawling across a cowpat on Common moor.
   Adults occur from July to October and are nocturnal, being found on or near Achilea millefolium (Yarrow), by day they shelter around the base of the plants. Eggs are laid in the autumn and probably again in the spring although to a lesser extent and the nocturnal larvae have been recorded from March to late June. The species has exacting habitat requirements and parts of Common moor would seem to be ideal with large open areas of short grazed grass on dry sandy soil with an abundant supply of the foodplant. In Britain also recorded from Sea Plantain (Platago maritima) and Wild Mignonette (Reseda lutea). From the continent also associated with Artemesia spp., Chrysanthemum spp. and Tripleurospermium inodorum.
   5-7mm. Upper surface dark metallic bronze, appendages black, base of antennae lighter, at least underside of joints 1 or 2. Head finely punctate with Y shaped impression. Pronotum finely punctate with front angles produced to a point, with coarsely punctate impressions near hind angles and from these a band of larger punctures runs to front margin. Hind margin as wide as elytral base, strongly sinuate. Scutellum impunctate (X15) and shining. Elytra dull from strongly granulate microsculpture so contrasting with pronotal disc, with 9 rows of strong punctures (counting across middle), weaker around scutellum. Finely punctate between rows of larger punctures. Entire margin outside 9th stria, including epipleurs, red, not visible from above. Underside black. Tibiae gradually thickened, not toothed but with a series of truncate bristles apically that may be mistaken for teeth at low power. External surface flat between lateral ridges, at least towards apex on hind tibiae, finely pubescent towards apex of inner surface.

¹ West Suffolk, NW. Yorks, Durham, S.Northumberland and Moray

Description from 1 Watford specimen at X15