No. 4.] 



SCALE INSECTS. 



435 



puri)lisli young, which crawl alxjut, as do those of tlie oyster- 

 shell scale, for a few ckiys before settling down to feed. The 

 remainder of the life history is similar to that of the last- 

 named insect, and the treatment for both is the same. 



The scuifv scale occurs on the a])ple, pear, quince, peach, 

 currant, Japan ((uince, mountiiin ash and many other plants, 

 but is not ifenenillv so abundant as to endanger the life of 

 the plant. 



Lecaniutvis, or Soft Scales. 



These scales are very different in appearance from those 

 already considered, being comparatively soft and easily 

 crushed. Moreover, they are quite large as compared with 

 most of the hard or "armored" scales, and when adult are 



Fig. 5. — Peach soft scale: female scales, on twig, natural size; upper side of a scale 

 in upper left corner, under side of same in lower left corner; scale cut lengtliwaj-s in 

 middle of left side; young, and full grown hut still crawling scales, on riglit sitle; all 

 much enlarged except the scales on the twig. (Howard, U. S. Dept. Agr., Yearbook, 



1894.) 



very convex, many having a nearly hemispherical form 

 (Fig. 5). They feed on the juices of many plants, includ- 

 ing palms and ferns in greenhouses, give trouble to fruit 

 growers on plum and other fruit trees, and are often seriou>s 

 pests on maples, oaks, tulip trees, etc. 



In many cases nature has established a sort of equilib- 

 rium for these insects which, after two or three years of 

 great abundance, are overcome by their foes, and are not 

 again abundant enough to be noticed for a number of years. 

 AMicre treatment seems to be necessary, however, it must 



