THE SWALLOW PROMINENT. 69 



generally In the afternoon ; it sits on the tree trunk to expand 

 and dry its wings, and then ascends higher up the tree. It is 

 found in Berkshire, Buckinghamshire, and in most of the 

 southern counties of England, and in the west, but it seems to 

 be rarer eastward and northward, and also in Scotland. In 

 Ireland it has been found, very sparingly, in Wicklow and 

 Kerry, and " numbers were taken in a moth trap at Clonbrook." 

 The range abroad is very similar to that of the next species. 



The Swallow Prv^minent {P/icosia tremula). 



Normally whitish, with a brown shaded black stripe along 

 the inner margin of the fore wings, and a brownish cloud, with 

 black streaks in it, towards the tips of these wings ; the outer 

 extremities of the veins are white, there is a white wedge-shaped 

 streak between veins i and 2, and from the apex of this an 

 indented white line runs to the base of the wing. Sometimes 

 the whole discal area is suffused with brownish. The moth is 

 shown on Plate 28, Figs. 4, 5, and the early stages on Plate 29, 

 Figs. 2, la, and ib. The ^t'g'g when laid is creamy white, and 

 the newly hatched caterpillar is pale green. When full grown 

 the caterpillar is green with rather darker, but not always clearly 

 defined, lines along the back, and a yellow line along the region 

 of the black spiracles ; the underside is sometimes reddish. 

 Another form is brownish in colour and the yellow line is then 

 generally obscure. The green form is figured on Plate 29. 

 The usual food is poplar, but sallow is also eaten. It may be 

 found in late June and early July and again in September and 

 October. The chrysalis is reddish brown and glossy except on 

 the wing covers, which are granulated and appear darker. The 

 cocoon is roughly constructed of silk and earth, and before 

 spinning it the autumnal caterpillar sometimes burrows a good 

 depth under the surface of the soil ; the summer cocoons are 

 said to be made up among leaves. 



