144 



AN INTRODUCTION TO ENTOMOLOGY. 



the fact that the ndult female excretes a large cottony mass in which 

 the eggs arc laid. Fig. \ i~ represents I'ulrintJria innmncrdlulis, 

 which is common on grape, niapK orange, and other plants. 



Ccropldstcs. The species belonging to this genus are furnished 

 with a thick covering of waxy material, which does not, however. 

 adhere closely to the insect. Only two species have been found in 

 the United State-. Both of these are Florida insects, and in each the 

 waxy covering is dirty-white in color. The most common sp<. I 

 C. Floridfnsis (Fig. US-, infests a great variety of plants both wild 

 and cultivated. C. cirripcitiformis (Fig. 129) is not very common ; 

 it infests orange and quince. It is a beautiful species, as the \\a.\y 

 excretion is in the form of regular-shaped pla' 



Sub-Family III. 



The Diaspina includes those species of scale-insects that form a 

 scale composed in part of moulted skins, and partly of an excretion of 

 the insect. This apparently trivial character is correllated with im- 

 portant structural characters, which mark a well-defined group. The 



:} . Organs of the last segment of adult females of the niasfhttr. a, opening of oviduct; 

 b. anus : </, d, ccphalo-lateral groups of spinnerets ; /, t, caudo-lateral groups of spinm-n 

 lobes ; k, spines ; /, plates (these are frequently described by authors as spines). (From a Report 

 by the Author, 1881.) 



most important of the structural characters is the peculiar form of 

 the last segment of the body. This segment is highly speciali/ed 

 for the excretion and manipulation of wax. It is furnished with 

 many openings and appendages. These vary greatly in number and 

 form, and afford good character^ for distinguishing closely allied 



* Diasplrue, Diaspis: dia (did,) through; asfis (a'cnrj'S), a shield. 



