14 REPORT ON INJURIOUS INSECTS FOR 1906. 



Judging from experiments made this spring, the winter sprayfluid 

 V i seems likely to prove effective here ; if that should ultimately prove 

 to be the case, it will be much easier to attack with this than with the 

 caustic soda-emulsion. 



Experiments have also been made with the fluid V 2, when the 

 trees are in leaf, with excellent results. 



THE HOP APHIS. 



Phorodon humuli, Schrank. 



Not for thirty years at least has this insect been such a plague. 

 Appearing on the byne early in June, there was an almost constant 

 migration of the pest throughout the summer. 



The climatic conditions which prevailed were all in its favour, 

 and growers were put to great expense owing to the repeated washings. 



I have pointed out to many Worcester growers the necessity for 

 spraying Plum, Damson, and other prunes with the caustic soda-emul- 

 sion sprayfluid in the winter, and again in the spring with paraffin 

 emulsion. If some united action were taken, I am sure it would be pro- 

 ductive of great good. 



In the vicinity of many Worcestershire hop plantations there are 

 standing to-day Damson, Plum, and Sloe trees which should have been 

 cut down and burnt years ago. They are old, neglected trees, bearing 

 no fruit indeed, the only purpose they fulfil, so far as I can see, is 

 to form a breeding ground for the Hop Aphis. 



THE PLUM APHIS. 



Aphis pruni, Reaumur. 



Throughout the Midland Counties this insect has been most plenti- 

 ful wherever Plums were grown. Not a few of the orchards have been 

 sprayed with the caustic soda-emulsion with excellent results, others 

 are being treated with the liquid V 2. 



THE APPLE LEAF APHIS. 



Aphis fitchii, Sanderson. 



Thanks to the excellent work of Professor Dwight Sanderson, we 

 now know that there are three distinct species of Aphis attacking the 

 Apple, viz. : 



The Apple Leaf Aphis (Aphis Jitchii, Sanderson). 

 The Permanent Apple Aphis (Aphis pomi, De Geer). 

 The Rosy Apple Aphis (Aphis sorbi, Kaltenbach). 

 The first-named species has been the common species in the Mid- 



