SCALE INSECTS. 271 



mussel-like in form. It is now, however, placed in the genus 

 Lepidosaphces, and under the specific name uhm. The mussel- 

 scale is brown, from J^- to ^- of an inch long, and of nearly 

 uniform width, except in the front, where it tapers to a point. 

 Sometimes the scales are straight, at others curved. The eggs 

 are creamy-white, and may number between eighty and ninety, 

 being scattered about under the scale : we find them in the 

 winter. There is only one brood : the young six-legged larvse 

 (fig. 155, iv) appear in June, and soon settle down to form 

 fresh scales. The male scales (vi) are much smaller than the 

 female (v). It is a widespread insect, occurring in America, in 

 Australia, and in S. Africa. 



This, like all scale insects, is spread from tree to tree and 

 orchard to orchard by the wind, and on the feet of birds and 

 the back of insects. It has been noticed that some scale-larvas 

 prefer the back of dark-coloured beetles. Young apple-trees 

 suffer severely from this pest in Britain, and should be 

 thoroughly cleaned before being planted. 



Prevention and Remedies. — Scale insects are often difficult to 

 destroy. Fumigation of young stock with hydrocyanic acid 

 gas and the application of caustic washes in winter are most 

 successful remedies. Paraffin emulsion spraying is beneficial 

 for some of the soft scales and when the hard scales are young 

 in summer. 



The Broivn Currant and Gooseberry Scale (Lecanium persiae, 

 v. ribis, Fitch). 



This is one of the soft scales, the female's dried body re- 

 maining over the egg mass and forming a false scale. It occurs 

 on the twigs of many other trees and bushes besides currants 

 and gooseberries. The dead skin or adult skin with the ova 

 beneath is an oval brown body, convex and notched behind, 

 about ^ inch long. The eggs occur under this brown covering 

 as a yellowish dust with wool, and hatch in autumn into small 



