292 The Spraying of Plants. 



by trapping the larvae under bands of burlap, or some similar 

 material, bound about the trunks of the trees. 1 



Imported Elm-leaf beetle; Elm Flea-beetle (Galeruca xantho- 

 melcena, Schr.). Description. The mature insect resembles 

 the striped cucumber-beetle in size and markings. The larva 

 is long, slender, and yellowish-black. It has a yellow band ex- 

 tending along the back and sides. The pest is most active from 

 May till August, eating the soft tissues of the leaf, but not the 

 veins. There are three or four broods. Serious eastward. 



Treatment. The arsenites should be used when possible, 

 spraying the tree thoroughly. When large trees are attacked, 

 the insects may be destroyed by pouring hot water into all 

 crevices and cracks about the base of the tree and in the imme- 

 diate neighborhood. The insects pupate at the surface of the 

 ground wherever a slight shelter can be found. Kerosene 

 emulsion applied in the same manner would also probably 

 prove effective in their destruction. 



Willow-worm. See under WILLOW. 



GOOSEBERRY. 

 FUNGOUS DISEASES. 



Mildew (Sphcerotheca Mors-uvce, B. & C.) . Description. The 

 fungus attacks the foliage and young fruits soon after the buds 

 have broken. The first appearance is the formation of a cob- 

 web-like covering which fits close to the plant. Later these 

 areas become whitish, and apparently sprinkled with a fine 

 white powder. Affected leaves and shoots are checked in their 

 growth, and finally they become dry and brown ; diseased shoots 

 often branch freely (Fig. 57). The berries are checked in 

 their growth, and generally drop from the bushes long before 

 the time of maturity. They also show the powdery covering. 



Treatment. The disease is caused by a surface fungus, and 

 the white threads seen on the host-plants form the body of the 

 parasite. This may be destroyed by applications of fungicides, 

 especially some of the copper compounds, or of the sulphide of 

 potassium. Weekly applications of the latter have given excel- 

 lent results. To avoid staining the berries, clear fungicides 



* See the reports of the Mass. State Bd. of Agric. on the " Extermination of the 

 Gipsy Moth." 



