6o THE MOTHS OF THE BRITISH ISLES. 



the second outwardly edged with ochreous, and preceding the 

 first is a series of black dots. 



The full-grown caterpillar, which is green, with a yellow-edged, 

 purplish, irregular stripe on the back, is figured on Plate 23, 

 together with a very young example, the purplish-black eggs as 

 laid, and the red-brown chrysalis. The cocoon from which the 

 chrysalis was extracted was spun up on a fairly stout twig of 

 poplar, from which some of the bark had been torn ; the cocoon 

 was formed, as regards the upper part, on the bare twig, and 

 this was covered with gnawed wood, instead of with bark 

 fragments, as is the lower end. The moth is figured on Plate 

 22, and the early stages on Plate 23. 



The moth emerges in June, sometimes in July, and may 

 occasionally be found at rest on the trunks of poplars, on which 

 the caterpillar feeds from July to September ; also on adjacent 

 walls or palings. The cocoons are made up on the surface or 

 in the chinks of the bark, and may be searched for, all through 

 the winter and early spring. It is curious to note how readily 

 these are detected after the moth has escaped, and how difficult 

 they are to see before that event. Usually there is but one 

 brood in the year, but in the hot summer of 1906 a male 

 specimen emerged from a few chrysalids that I had reared from 

 eggs laid at the end of June of that year. On the other hand, 

 the moth has been known to remain in the chrysalis for two 

 winters. 



The species is not uncommon in some parts of the London 

 district, and seems to occur throughout England wherever 

 poplars abound. It does not appear to have been found in 

 Scotland, and is scarce in Ireland. Abroad it is found in 

 Central Europe with a northern range to Finland, southwards 

 to Italy and Greece, and eastwards to the Altai. 



