218 FOREST ENTOMOLOGY. 



some districts, and entirely absent in others. I have, for instance, 

 never taken it in Northumberland. It is generally found on the 

 stems of very old plants, and then often so abundant as to completely 

 cover the bark. 



The female scale is of circular form, slightly convex, and from 2 

 to 3 mm. in diameter. The central or larval exuviae generally lies 

 between the centre and the outer edge of the scale. It is of a dull 

 canary colour. The exuviae of the second moult is yellowish-brown, 

 and the scale proper is a dirty-white-looking colour. Collectively, 

 they give a sort of drab colour to the infested stem. 



Prior to the deposition of the egg, the body of the female is of a 

 dull orange-crimson, and the pygidium, which is rather conspicuous, 

 is a bright orange. The body, though elongated, has a slight leaning 

 towards a rough circular outline, and the front portion is almost a 

 perfect semicircle. The outline of the body shows the segmentation 

 very clearly. 



The male scale is elongated, and very much resembles the puparium 

 of Chionaspis. It is of a whitish colour, and the exuvia varies in 

 colour from bright-yellow to red-orange. If examined carefully, it 

 will be seen that the white portion possesses three linear ridges, the 

 centre one being more raised than the other two. 



The male of this species, and also the male of the genus Diaspis, 

 resemble the male of Chionaspis, both as regards the form of the 

 scale and the perfect insect. The body is crimson, and the wings 

 whitish. The eyes are black, and the antennas long and slender, with 

 very delicate hairs. The legs are yellowish, and slightly pubescent. 



There is an important point in connection Avith the life-history of 

 this species, as compared with the genus Chionasjns, and the advice 

 given by Linnaeus, " Observe and compare," is very applicable to the 

 study of scale-insects. It has been noted that the larvae of Chionaspis 

 hatch out early in May, assume a quiescent stage after a few days' 

 active existence, and that eggs are found underneath the scale from 

 September to May. The active larvae and eggs of A. rosce, on the 

 other hand, are found throughout the year. I have found active 

 larvae, together with eggs and females, in November of one year, and 

 also in January of the following. Newstead says that the eggs are 

 deposited in August, and that there is only a single brood in the year ; 

 and the apparently abnormal character of eggs and active larvae being 

 found together shows that where egg-laying extends over a consider- 



