1907.] Insect, Fungous and other Pests. 



22 f 



Aphides on Willows were forwarded from Ormskirk, where 

 they were present in great numbers on the shoots and were 

 doing much damage. Drawing a gloved hand over the infested 

 shoots would destroy them in hundreds. Infested willows- 

 might be sprayed with either of the following mixtures : — - 

 (1) 10 lb. of soft soap dissolved in 100 gallons of soft water 

 and mixed with the extract obtained by boiling 8 lb. of quassia 

 chips in water. As the spray will dislodge many of the insects 

 the ground should be sprinkled with lime to prevent them 

 re-ascending the trees. (2) Paraffin 2 gallons, water 1 gallon, 

 soft soap \ lb. The soap should be dissolved in boiling water 

 and the paraffin then added and the whole churned thoroughly. 

 This " stock " emulsion should be diluted for use, in the pro- 

 portion of 10 gallons of water to 1 gallon of " stock." 



Aphides on Scotch Firs. — Another case of aphides submitted 

 to the Board revealed the presence on Scotch firs of aphides of 

 the genus Lachnus. By the aid of a pocket lens the long 

 sucking tube which the insect drives into the plant tissue,, 

 thence drawing away the sap, can plainly be seen. These 

 aphides may be destroyed by treatment with the soft soap- 

 wash or the paraffin emulsion recommended against aphides in 

 Leaflet No. 104. 



Other pests submitted for identification were the Apple 

 Sucker (see Leaflet No. 16) from Newton Abbot, and Millipedes 

 (see Leaflet No. 94) from Probus (Cornwall), where they were 

 attacking several garden crops, and from Longniddry (Hadding- 

 tonshire), where they were severely damaging mangolds. 



Fungi. — Among the specimens infested with fungous diseases,, 

 rhubarb plants forwarded from Portobello, N.B V were attacked 

 by the fungus Rhizoctonia violacea, Tub, causing root-rot. 

 This disease is described in Leaflet No. 171. From Burton 

 Joyce, Nottingham, a correspondent sent a spray of plum 

 leaves infested with the disease known as " Silver Leaf," which 

 was found both on wall and standard plum trees. Neither 

 cause nor cure is known, but the addition of lime to the soil 

 has been recommended. Branches that are attacked should be 

 removed and burned, as they do not recover. 



Shot-Hole Fungus. — Diseased peach leaves from Westbury, 

 Wilts, were injured by the " Shot-hole " fungus, Cercospora 

 circumscissa, Sacc. As a preventive measure spraying should 



