ORCHARD PESTS 91 



winter, when the bushes should be sprayed with caustic 

 soda wash. (See Plate 20.) 



Next is the Currant Sawfly (Nematus ribesii) which 

 perhaps is just as well named the Gooseberry Sawfly, as 

 it leaves its mark on the one bush as much as the other. 

 They clear the leaves off altogether in some seasons. The 

 larvse, which are green with black spots, have the twenty 

 legs which distinguish all sawfly larvae from moth cater- 

 pillars, who only have sixteen, and are nearly an inch 

 long when full grown. It changes into a green chrysaUs 

 within an oval brown cocoon, and the adults, which mea- 

 sure nearly | inch across the wings, first come out in May. 

 There are several broods in the season. The eggs are 

 conspicuously laid along the veins of the leaves, and so 

 Uttle need be said as to how to deal with them. Various 

 sprays are used against the caterpillars, but I recommend 

 strong lime water only, sprayed all over the bush. In 

 the winter also a good plan is to remove all the surface 

 soil for some inches beneath the bushes and replace same 

 with fresh. (See Plate 20.) 



The Currant Gall IVIite is not an insect, but an Acarus, 

 minute creatures produced from eggs, but undergoing 

 no preliminary stages of development. The present 

 species {Eriophyes rihis) which affects currants and goose- 

 berries is only yjo inch in length, and so can scarcely be 

 seen without a pocket lens, but its effects are apparent 

 enough in the shape of the " Big Buds " from which the 

 plants suffer in the spring and which afterwards dry up 

 and die. Incredible as it may seem, these tiny creatures 

 have a still tinier parasite, an insect which calls itself 

 Tetrastichus eriophyes, but I am afraid I cannot convey 

 any notion as to the size, or rather the smallness of this 

 little helper whose larvae eat Currant Mites, or how you 

 box it when its presence is rumoured. Our methods of 

 control are chiefly change of site for the new bushes when 

 the old ones are burned, although spraying with soft soap 

 and sulphur in the springtime may be tried. These, added 



