60 PULVINAEIA VITIS, VAE. RIBESI^E. 



bark until the wind carries it away. After this moult 

 many of the females change their quarters, but the 

 majority remain where they first fixed themselves as 

 young larvae. Growth takes place immediately after 

 the moult, and by the third week in October the insects 

 attain a length of 3-4 mm. (PL XL VI, fig. 1). Their 

 colour then closely resembles that of the bark of the 

 food-plant, and is thus highly protective, so much so 

 that even when the branches are almost covered with 

 coccids the latter are by no means conspicuous. The 

 insects pass the winter in the stage last described, 

 and early in March, if the weather is warm and 

 sunny, the females begin to show signs of growth, and 

 to secrete honey-dew ; should the weather change 

 to cold and frost, they again become dormant, as in 

 winter ; but they begin to re-eject the secretion when 

 warmer weather again sets in. It is, however, 

 during the last fortnight in April and the first week in 

 May that the greatest amount of honey-dew is expelled. 

 Towards the end of April the females thicken, and the 

 margin of the body formerly fixed to the branch 

 becomes raised from the middle to the posterior 

 extremity, thereby slightly exposing the underside, 

 which presents a dull orange colour (PL XL VI, fig. 2, 

 two specimens). At this stage the formation of the 

 ovisac is commenced (PL XL VI, fig. 2), but the eggs 

 are not laid in it until the pad-like sac has attained the 

 thickness shown in the illustration. The completion 

 of the sac represents the period of egg-laying; in- 

 dividually this occupies altogether about twenty-one 

 days, but collectively it is continued over a much 

 longer period. The females, during the process of the 

 formation of the ovisac, become gradually tilted up 

 from behind, until, eventually, they are only attached 

 to the branch by the anterior or cephalic margin 

 (PL XLV, fig. 1 a), which position is maintained for an 

 indefinite period sometimes for two or three years. 

 Death takes place shortly after the egg-laying period ; 

 the body then changes to a chocolate-brown, and 



