SCALE INSECTS OF IMPORTANCE 307 



marked adult female scale reveals the following characteristics. It is al- 

 most 2 mm, or -^^ inch, in diameter, neady circular, grayish, with a cen- 

 tral darker nipple surrounded by one or more rather well-defined yellowish 

 rings <fig. 9). The smaller scales are nearly black, with a central nipple, 

 and one or two grayish rings as represented in figure 13. The largest 

 scales are just about the size of the head of an ordinary pin, while the 

 smaller ones are mere dots, as represented by the black specks on the 

 twig, figure 5. Sometimes the female scales have a distinct yellowish 

 shade, as shown in figure 6. The yellow, usually somewhat kidney- 

 shaped female insects may be found under the scales. A gravid female 

 is shown much enlarged in figure 10. Note the oval young within her 

 body and the slender proboscis apparently composed of two filaments 

 but in reality of four. The yellow, active young is shown much enlarged 

 in figure 11. The antennae, six legs and slender proboscis are all pres- 

 ent. The young appear as minute specks when on the trees. They 

 soon cover themselves with a white excretion, and then they appear like 

 white dots surrounded by red, whenever they establish themselves on 

 green fruit or bark (fig. 2). The form of the white scale and the colored 

 area around it are represented in detail in figure i. 



The male scale may be easily recognized by its elongated shape with 

 the nipple near one end (fig. 8). The delicate, two-winged male is rep- 

 resented much enlarged in figure 12. 



Life history. The winter is passed by this insect in a partly grown, 

 dormant condition. Vital activities are resumed with the approach of 

 warm weather, and the first outward indications of Hfe are seen in the 

 appearance of winged males and later of the crawling young, the latter 

 of which appear in this latitude toward the last of June. The life his- 

 tory of this insect has been studied in detail at Washington (D. C.) 

 under the direction of Dr L. O. Howard ; and from his account most of 

 the following details are taken. The females continue to produce young 

 for a period of about six weeks, each averaging about 400, or from nine 

 to 10 every 24 hours. This is an ovoviviparous species. That is the 

 eggs develop within the mother and the young are born alive. They 

 may be seen as tiny yellow specks escaping from under the maternal 

 scale, from which they wander in search of a favorable place to establish 

 themselves. This pilgrimage occupies relatively few hours (an average 

 of a little over 27! hours, according to Prof Lowe), and the young 

 soon establishes itself, works its slender proboscis through the bark and 

 begins to draw nourishment from the plant. The development of the 



