asthena] HYDRIOMENIDAE 225 



times suffused with grey or fuscous ; veins partially marked 

 with dark fuscous, especially in middle of disc ; sometimes a 

 dai-k fuscous discal dot. Hindwings grey- whitish, posteriorly 

 with grey striae. 



Britain to the Orkneys, Ireland, common ; N. and C. Europe, 

 WC. and N. Asia, N. America ; 9, 10. Larva rather stout, 

 green, often yellow -dotted ; dorsal line darker or formed by 

 purple spots ; subdorsal sometimes darker ; lateral sometimes 

 yellowish ; spiracular yellow or whitish, sometimes partly 

 purplish-edged: on oak, birch, blackthorn, etc.; 5, 6. 



21. Venusia, C^l,rt. 



Face smooth. Antennae in $ bipectinated, aj)ex simple. 

 Palpi loosely scaled. Forewings : areola simple. Hindwings : 

 8 anastomosing with cell to beyond middle. 



There is only one European species ; three others are known 

 from New Zealand. 



1. V. cambrica, Curt. 25-28 mm. Forewings whitish, 

 dusted with dark fuscous, with fuscous striae ; edges of 

 median band blackish -marked, posterior twice subsinuate, 

 followed by short blackish dashes on veins, especially on a 

 median V-sha])ed mark. Hindwings whitish, with grey striae 

 on posterior half. 



Norfolk, WC. and N. England to Ross, N. Ireland, rather 

 local ; N. and C. Europe, N. Asia, Japan, N. America ; 6, 7. 

 Larva pale yellowish-green, blotched irregularly with reddish- 

 purple ; dorsal line pale yellow : on Pyrus aucuparia ; 8, 9. 



22. Xanthorhok, Hb. 



Face with somewhat projecting scales or conical tuft. 

 Antennae in c? bipectinated, apex usually simple. Palpi rough- 

 scaled. Forewings : areole double. Hindwings : 8 anastomos- 

 ing with cell to beyond middle. 



A large genus, but less numerous than Hydriomena in all 

 regions except New Zealand, where it is dominant. The 

 antennal pectinations are sometimes very short, but then always 

 terminate in long fascicles of cilia. 



1. Forewings green . . . .2. 



,, not green . . . .3. 



2. Forewings with triangular black costal spots 



18. viridaria. 

 „ without black costal spots . 17. olivata. 



Q 



