COCCID^ OF KANSAS, IV. 



Additional Species, Pood-plants and Bibliography of Kansas Ooccidae, with 

 Appendix on other Species Reported from Kansas. 



BY S. J. HUNTER. With plate VIII. 



A.— Additional Species. 

 Ket'ines pnbescens Bogue. Plate VIII, fig. 1. 

 On white oak, Lawrence, Douglas county. 



Kermes nivalis King and Ckll. Plate VIII, fig. 2. 

 On white oak, Lawrence, Douglas county. 



Ovthezia gva minis Tinsley. Plate VIII, figs. 3, 1. 

 On goldenrod (SoUdago sp,), Blue Rapids, Marshall county. Mrs. 

 S. Gr. Cady, collector. 



B.— Food-plants of Kansas Coccidae. 

 In order to understand the significance or importance of the food- 

 plants of Coccidse, or scale-insects, some knowledge of the life and 

 habits of the insect is necessary. Scale-insects are plant parasites 

 and locate themselves upon the bark or outer covering of the plants. 

 They have long, slender beaks, which they are able to insert into the 

 tissues of the plants and draw therefrom the plant juices. Some scale- 

 insects choose but a single host-plant, and others seem to be able to 

 subsist upon a very great variety of plants. This adaptability to va- 

 rious food-j)lants has much to do with the numbers of the several 

 species in existence. It is evident that if a species of insect has to de- 

 pend exclusively upon a single plant variety, the chances of life for 

 this insect would decrease with a decrease in numbers of the host ; 

 while, on the other hand, scale-insects which have the power to adapt 

 themselves to a number of plants have greater chances of life and 

 better opportunities for numerical increase. In animal parasitism 

 the parasite tends to increase as the host increases. The increase of 

 the parasite, however, is generally in a greater ratio than the increase 

 of the host, so that the parasite frequently becomes so numerous as 

 to destroy or greatly curtail the increase of the host, and then the 

 parasite must succumb likewise, or adapt itself to new conditions. 

 Such relations between host and parasite exist to a certain extent be- 



[1071 -K.UAir.— A X 3-July, '01. 



