14 REPORT ON INJURIOUS INSECTS FOR 1905. 



Soft soap 5 Ibs., tobacco \ lb., water 5 gallons, the whole to be 

 well boiled together, and when applied add three gallons of water 

 to every gallon of the mixture. 



THE APPLE SUCKER. 



Psylla mail, Forster. 



From Hereford, Worcester, and Warwick many inquiries have 

 been received respecting this pest. There can be little doubt that 

 it is spreading and infecting new orchards. 



A number of experiments have been made to test the action 

 of the soda and potash sprayfluid upon the eggs, and, whilst it 

 sometimes happens that the eggs are not all killed, all the experi- 

 ments I have made go to prove that if the sprayfluid is properly 

 made and applied, and does not contain too much soft soap, 

 comparatively very few of the eggs hatch out.* Mr. Fred V. 

 Theobald,! in his valuable report for 1904, states that "If the ova 

 are just ready to hatch, the embryos are killed," but unless in that 

 condition it has no effect. Whilst all the experiments I have made 

 point tc the fact that the later the application is made the better 

 are the results, they also support my contention that there is a 

 marked diminution in the number of larvae on trees which have 

 been sprayed in January or February, over those which have not. 



Mr. Theobald also draws attention to a feature I have not 

 noticed in the Midlands, viz., that this Psylla frequents hawthorn 

 hedges around orchards, so that unless they are also sprayed but 

 little good will be done. 



THE LARCH AND SPRUCE CHERMES 



Ckermes abietis, Linn. 



The insect which gives rise to the only too well-known pine- 

 apple galls of the spruce has a most complicated life-history, which 

 has formed the subject of numerous biological memoirs, not the 

 least valuable of which is one by Mr. E. R. Burdon, issued during 

 the past year.J 



Early in 1905 Mr. Burdon published a summary of a most 

 valuable paper dealing with the early stages of the development 

 of the galls formed by this species. As the complete paper will 

 not be published for some time, he has very kindly permitted me to 

 read through his MS., and to make an abstract of the damage done 

 to the host plant, and the results of his experiments on prevention 

 and cure, and his results will, I feel sure, be greatly appreciated 

 by foresters and others. 



The following is an abstract taken from Mr. Burdon's MS. : 

 Of the various generations, only one, that on the spruce, induces the 

 formation of a gall, though all more or less damage the plants by 

 sucking 



* It is very important that a spraymarker should be mixed with the sprayfluid. 



t Journ. S.E. Agric. Coll., 1905, p. 39. 



i Proc. Camb. Phil. Soc., 1905, vol. xiii, pt. i, pp. i2-ig. 



