The Control of Ixsect Pests and Plant Diseases. 



589 



San Jos^ Scale. Scurfy Scale. Oyster-shell Scale. 



Fig. 195. The three common scales infesting the apple. 



Oyster-shell 

 scale. 



(Fig. 195.) 



This is an elongate scale, J inch in length, resembling an oyster 

 shell in shape and often encrusting the bark. It hibernates 

 as minute white eggs under the old scales. The eggs hatch 

 during the latter part of May or in June, the date depend- 

 ing on the season. After they hatch, the young may be seen as tiny whitish lice 

 crawling about on the bark. When these young appear spray with kerosene 

 emulsion, diluted with 6 parts of water, or whale-oil or any good soap, i lb. in 4 

 or 5 gals, of water. 



This whitish pear-shaped scale, about \ inch in length, often 

 encrusts the bark, giving it a scurfy appearance. It hibernates 

 as purplish eggs under the old scales. Spray as recommended 

 for oyster-shell scale. 



The presence of this minute mite is indicated by small irregular 

 brownish blisters on the leaves. Spray in late fall or early spring 

 with the home-made lime-sulfur or with the 

 concentrated lime-sulfur solutions, i gal. in 10 

 gals, of water. Geneva Bulletin 306. 

 Round-headed The only practicable method of control is to dig 

 borer. out the borers or kill them with a wire. 



The insect hibernates in the egg state. The eggs 

 are glued in ring-like brownish masses (Fig. 196) 

 around the smaller twigs where they may be 

 easily found and destroyed. The caterpillars 

 appear in early spring, devour the tender leaves, and build un- 

 sightly nests on the smaller branches. This pe.st is usually con- 

 trolled by the treatment recommended for the codling-moth. Des- 

 troy the nests by burning or by wiping out when small. 



Scurfy scale. 

 (Fig. 195.) 



Leaf 

 blister-mite. 



Apple tent- 

 caterpillar. 



Fig. 196. Egg 

 ring of apple 

 tent-cater- 

 pillar. 



