Notes on the Life History and Habits of 



the Rose Scale, Aulacaspis rosce 



Bouche 



SHONOSUKE NAKAYAMA 

 STANFORD UNIVERSITY, CALIFORNIA 



The present paper on the rose scale is based on observations 

 made in the vicinity of Stanford University from December, 1912, 

 to April, 1914. The paper was prepared in the Entomological 

 Laboratory of Stanford University. 



LIFE HISTORY AND HABITS 



The rose scale is a common insect pest of blackberries, raspber- 

 ries and roses. It is widely distributed throughout the world. The 

 most comprehensive paper dealing with the biology of this insect is 

 found in Bulletin 159, 1902, of the New Jersey Experiment Station. 

 In this bulletin. Dr. John B. Smith gives a detailed account of the 

 life history and habits of this insect in New Jersey, Nothing has 

 been published in regard to the biology of the rose scale on the 

 Pacific Coast. 



A. DEVELOPMENT 



1. The Adult Female 



The female scale is dirty white. Its shape Is subcircular or 

 widely ovate. The body is flat and elongated, orange yellow or 

 golden yellow in color. As the eggs begin to develop, the body of 

 the female turns orange color and the eggs are plainly visible 

 through the body under a high magnification (PI. I, Fig. 20). For 

 a complete technical description of this insect, the readers should 

 see Rep, U, S. Dept, Agric, 1880, p. 312, and Newstead's Mon. 

 Brit. Coccidae I, p. 168. 



2. The Egg and Its Oviposition 

 The minute and oval-shaped egg, not exceeding .1 1mm. in length, 

 is orange yellow when first deposited (PI, I, Fig. 2) . It turns from 

 pale to brownish yellow a few days later, and again changes to 



