198 



Insect Pests. 



A 



[F. E. 



FIG. l. r >4. NY.Ml'H OF THK CHKKKY 



APHIS (Myzu* cerasi). 

 ((Jreatly enlarged.) 



LlFE-HlSTOEY AND HABITS. 



The wingless viviparous female is black and rather shiny, with 

 yellowish and black legs. This female as a rule appears low down 

 on the leaves in spring and has sprung from an egg laid on the 

 cherry tree. She soon produces pale lice, which darken and grow 



into wingless viviparous females, and these 



seem to ascend to the top shoots, over 

 which they swarm and produce countless 

 living young, which spread on to the leaves 

 and feed beneath them and cause them 

 to curl up, and in dry weather soon kill 

 them. In July many change to pupa?, 

 which have an olive-green appearance 

 with yellowish wing cases. These give 

 rise to winged viviparous females, which 

 have a black thorax, greenish abdomen 

 and black cornicles, with broad trans- 

 parent wings ; this female is about -^ inch 

 long. What becomes of these I do not 

 know. They certainly suddenly leave the 

 cherry trees. 



Buckton (5) records the viviparous form on the currant at the 

 end of October. Do they fly back to the cherry ? 



Certainly we find the eggs on the cherry (6), and the oviparous 

 form has been found there and is described as being dark shiny brown ; 

 the male, which is also found in October, is brownish-black with 

 yellowish abdomen with five brown transverse bars and lateral spots. 

 The egg-laying females I have found as late as the 5th of November 

 on young cherry trees in Kent. The oviparous females are wingless ; 

 the males are winged, and are said by AVhitehead to occur in mid 

 September. Each female lays from one to four eggs, sometimes on 

 the shoots, but, I have noticed, especially on any suckers growing 

 round a tree. They are black and shiny and placed near a bud. The 

 time of egg-laying must vary, for we find it recorded from September 

 to October, and it has been seen by myself as late as November. 



Wallace (4) records two swarms during the year, one in June 

 and the other in October. The latter swarm contains the males. 



PREVENTION AND THEAT.MENT. 



There is no doubt that autumnal washing would do much 

 good by destroying the late generation before the eggs are laid. 



