Insects, etc., Injurious to Currants. 225 



I have observed this species on the black, red, and white 

 currant. Miss Ormerod (3) records it from the black -currant and 

 also from Ribes sanyuineum, an ornamental species. 



Newstead (2) also records it from all three varieties and says it 

 occurs most freely on R. nigrum, to which it is often injurious. He 

 records it from Banffshire, Aberdeenshire, Kincardine, Edinburgh 

 City ; Arbroath and Berwick-on-Tweed ; from Bangor, North Wales ; 

 very common in Cheshire and near Liverpool. Mr. Denis Best 

 tells me he has had it in his plantations near Worcester (4). Mr. 

 Moseley records it from Huddersfield. 



In the neighbourhood of Paris and in other parts of France, it is 

 not at all an unusual pest on the red currant, and has long been 

 known to be destructive. 



The only observations I have made of it in England were on 

 wall bushes in the open, and in all cases the bushes were not in good 

 sunny positions, but were more or less sheltered. 



It is strange how suddenly this pest may appear, as seen in the 

 garden in Huntingdonshire. There is no doubt that it is easily 

 wind-borne and equally easily spread by birds, hence its sudden appear- 

 ance in isolated areas some distance apart. Some of the most 

 interesting notes on it are given by ISTewstead (2). He records how 

 the young hatch in June and until the first week in July, a period of 

 about twenty-eight clays. They are very active for a day or so and 

 tben disperse over the plants, ascending to the leaves and young and 

 tender shoots, but rarely fix themselves in such situations. They almost 

 invariably select the hard ripened wood of the previous year's growth. 

 Very little change takes place in the larvae at first, but by mid July 

 they undergo their first moult. At the end of August another moult 

 takes place. After this the first traces of reticulation show and the 

 distinction of sexes takes place. The males become more elongate 

 and more reticulate than the female. As soon as the elongate form 

 is reached the male enters the puparium stage. By the end of August 

 the male propupal stage is reached, and about seven days later the 

 white caudal filaments of the male are seen to protrude from under the 

 puparium. The males come from under the puparia in mid September 

 and go on appearing until the second week in October. The winged 

 males take a short rapid flight, more like a leap. About the end of 

 September the females effect their third moult. By the third week 

 in October they are nearly mature and closely resemble in colour the 

 bark of the food plant. The insect passes the winter in this stage, 

 and early in March shows signs of growth and secretes honeydew. 

 Towards the end of April the females thicken and the margin of the 



Q 



