12 REPORT ON INJURIOUS INSECTS FOR 1 906. 



tember the females effect their third moult, but on this occasion only 

 the ventral skin is cast off at the anal extremity, remaining- as a minute, 

 white, shrivelled object on the 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. 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 greater 

 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. At this stage the formation of the ovisac is commenced, but 

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

 thickness. . . . The completion of the sac represents the period of 

 egg-laying ; individually this occupies altogether about tw r enty-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, which posi- 

 tion 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 eventually almost black, 

 and is much wrinkled transversely. 



" Summarising these observations, we find that there is but one 

 brood in a year. The larvae hatch in June and the early part of July, 

 the first moult taking place from the middle of July onwards ; the 

 second moult is in August, when a sexual difference is first observed. 

 Pupation takes place towards the end of August, the males appearing 

 in September. They then fertilise the females, when the latter moult 

 again for the third time. Hibernation commences shortly afterwards, 

 and the insects remain dormant until the spring. Egg-laying takes 

 place a,t the end of April and throughout the early part of May. In 

 all probability the period here set forth may vary slightly according 

 to the season. My observations were made during the years 1899-1902, 



