THE TRUE BUGS 131 



in form that they would not be readily recognized as insects, were 

 their complicated life histories not known. Three quite distinct 



FIG. 181. The cochineal insect 

 a, on cactus; b, male; c, female (enlarged). (From Riverside Natural History) 



groups may be readily distinguished. The mealy-bugs are fre- 

 quently found on greenhouse plants, and are so named from their 

 mealy covering of wax and the numerous white, waxy filaments 



FIG. 182. The peach lecanium, or terrapin scale 



Adults at left (much enlarged and natural size) ; young at center and unfertilized female at 

 right (much enlarged). (After Howard, United States Department of Agriculture) 



which are given off from their bodies. They are from an eighth to 

 a quarter of an inch long, and move about slowly over the plant, 

 retaining their legs throughout life. The soft scales include those 



