258 LEPIDOl'TERA. 



costa strongly folded at the base, nearly straight ; apex 

 rather sharply angulated ; hind margin a little oblique ; 

 nmbreous, or olive brown, abundantly dusted with yellow 

 atoms ; before the middle a curved transverse pale silvery 

 brown stripe from the costa opens out into a similar erect 

 dorsal blotch ; the following silvery white costal streak is 

 produced back into a slender horizontal line ; remaining 

 costal streaks silvery-brown but shorter ; over tlie anal angle 

 is a glistening ocellus enclosed by silvery lines ; cilia 

 yellowish white tipped brown. Hind wings smoky white 

 with white cilia. Female similar, often darker, and without 

 the costal fold. 



Underside of the foi'e wings pale leaden brown with white 

 costal dots. Hind wings leaden white. 



On the wing from the end of May till July. 



Larva when young moderately slender, clear, semi-trans- 

 parent, yellowish-white, with a distinct internal dorsal 

 vessel ; head light brown, jaws black ; plates very pale brown. 

 When full grown, more plump, and the colour dull yellowish 

 white. February till May on yarrow (AcMllea millefolmm), 

 feeding in a gallery at the base of an old flower-stalk, after- 

 wards eating its way into the middle of the stem and clearing 

 out the pith down to the root-stock. xVlso in the root-stocks 

 of Chrysanthemum Icucantheomim. Assuming the pupa state 

 in the larval burrow. 



The moth loves any fields and waste places at the edge of 

 woods, quarries, chalk pits, railway banks and sandy spots 

 — wherever the yarrow grows in plenty in a dry soil. It flies 

 freely in the afternoon sunshine and suns itself sitting on 

 the plants, continuing active quite till dusk. Very common 

 iu the South of England, including the London suburbs, and 

 in the eastern and western counties ; much less common in 

 the North of England, and hardly recorded in the midland 

 counties: in Wales plentiful in Pembrokeshire and Glamor- 



