i8 



REPORT ON INJURIOUS INSECTS FOR 1905. 



diseased trees with hydrocyanic acid gas, and has obtained very 

 satisfactory results. 



So long as there is no law to compel certain owners of infected 

 trees to attend to the same, fruit-growers must suffer, for, however 



FIG. VI. FUMIGATING WITH HYDROCYANIC ACID GAS. 



careful and thorough the measures taken in one orchard may be,, 

 they will prove of little avail if nothing is done in adjoining 

 orchards, or others in the immediate district. 



PLUM APHIDS. 



Aphis pruni, Reaumur. 

 Hyalopterus pruni (Fabr.). 



Hitherto in both Warwickshire and Worcestershire the cornmou 

 aphis of the plum has been Hyalopterus pruni (Fabricius), but so 

 far as I can learn, during 1905 Aphis pruni, Reaumur, has been 

 much the commoner species, and also more destructive. 



This latter species has been forwarded by correspondents from 

 Sutton Coldneld, Solihull, Bromsgrove, Stafford, Leamington, etc. 



Early in the spring some trees planted on the experimental 

 plot at Bournbrook were found to be affected with the small green 



