322 THE GEOMETRINA. 



wliicli enables them to regain the leaves of the trees, 

 as soon as they think the danger has passed. They 

 usually suspend themselves to the branches of the 

 trees which they inhabit when about to undergo their 

 transformations, some of the pupae hanging freely by 

 the tail, whilst others are enclosed in a slight cocoon. 

 Very few bury themselves in the earth at this period, 

 but some descend to the surface and pass their pupa 

 state amongst moss and dead leaves. 



Another abundant species is the Brimstone Moth 

 {Rumia Cratcegata), which is of a beautiful sulphur- 

 yellow colour, with reddish spots on the edge of the 

 fore wings. It is found plentifully about the borders 

 of woods and hedge-rows, in March and April, and 

 occurs again at intervals until the autumn. Its cater- 

 pillars feed principally on the whitethorn and other 

 hedge shrubs. Many other abundant species are more 

 or less injurious to fruit-trees and cultivated plants, but 

 I shall close this section with an account of one, which 

 not only possesses this claim to our attention, but is 

 also remarkable for some peculiarities in its ceconomy. 

 This is the Umber Moth {Hibernia defoliaria) , the 

 caterpillar of which usually lives on lime-trees, but 

 also frequently attacks orchards, and sometimes, when 

 it exists in unusual numbers, does considerable injury 

 to fruit-trees. About the month of June this cater- 

 pillar descends into the earth to undergo its change 

 into the pupa state, but the perfect insects do not 

 make their appearance until the end of October or the 

 beginning of November. The male measures about 

 an inch and three-quarters across the wings, which 

 are of a yellowish colour covered with blackish points, 

 and with a dusky waved line running obliquely across 

 the anterior pair near the apex ; near the middle of 



i 



