GRASS EMERALD. 69 



dark, in order to prevent the bright emerald 

 green from fading away until scarcely an idea 

 can be formed of the original colouring. This 

 sensitiveness to light is found in the colouring 

 of many insects, but there are very few in which 

 the tints fly so quickly as is the case with the 

 present insect. 



The caterpillar is also green, being one of the 

 few instances in which the larva and the perfect 

 insect coincide in colour. It feeds on various 

 trees, the birch and beech being perhaps its 

 favourites, and the Moth flies in midsummer. 

 Woods are the best places in which to search for 

 this beautiful Moth, a figure of which is shown 

 on Plate V. fig. 8. 



The present family contains some eight spe- 

 cies, all going by the popular name of Emerald, 

 though the title is not so well deserved as by 

 the insect just described. The GRASS EMERALD 

 (Pseudoterpna cytisaiia) is one of them. It is 

 much smaller than the Large Emerald, and has 

 its wings of a greyish green, with a pair of dark 

 bands crossing the fore-pair. Mr. Newman men- 

 tions in his valuable work on the British Moths, 

 that " when this Moth comes out of the chry- 

 salis in wet weather, every part of it is suffused 

 with a red tinge." 



