THE WHITE WOOLY CURRANT SCALE. II 



THE WHITE WOOLY CURRANT SCALE. 



Pulvinaria ribesii, Sign. 



I recorded this scale in my last Report from Walsall, Wednes- 

 bury, and the neighbouring district. This year I have met with it in 

 quite a number of orchards in Worcester, though never in any great 

 quantity. 



It is a troublesome pest, and is best attacked, I think, by the use 

 of the caustic soda-emulsion. 



LIFE-HISTORY. 



The larvae hatch out in June- July. At first they are extremely 

 active, running all over the plant, but after a time they fix themselves 

 to the wood of the previous year's growth. Towards the end of July 

 they undergo their first moult, a second one taking place about the 

 middle of August. After this the sexual distinction commences to 

 appear. The following account is given by Newstead 1 : 



" Both males and females are at first identical, but the former 

 eventually assume a more elongate form, and the reticulations become 

 more confluent. These changes give the insect a darker appearance. 

 So soon as the elongate form is attained in the male insect, the pupa- 

 rium is commenced ; at first there is only a faint trace of the carinae, 

 but in a few days it is completed. Under this covering the insect 

 changes to the first pupal stage, finally losing the mouth-organs char- 

 acteristic of all the previous stages. Presumably, therefore, it takes no 

 further nourishment from the food-plant. Towards the end of August 

 the first pupal skin is moulted and pushed out at the anal extremity 

 of the puparium ; the true pupal form is then attained. About seven 

 days later the white caudal filaments of the male are seen to project 

 beyond the puparium ; at first they are short, but in the course of a 

 few days they assume their full length, when the tips of the wings may 

 also be seen projecting beyond the puparium. The first males appear 

 during the second week in September ; they continue to emerge over a 

 period of twenty-one days, the last hatching as late as the second week 

 in October. In confinement the males become very restless, frequently 

 taking a short, rapid flight, which reminds one more of a gigantic 

 leap. When the insect is about to take flight, the long caudal filaments 

 are carried semi-erect, and the wings are spread out and slightly ele- 

 vated. I did not observe any of the males take flight out of doors, 

 except when made to do so by disturbing them with a fine-pointed 

 instrument. After fecundation the males die. About the end of Sep- 



iMonog, British Coccidae, 



