EXPERIMENT STATION BULLETINS. 



241 



San Jose scale. The fact that it works on peach makes it especially unwelcome in our 

 State. 



The following description of the insect is taken from Professor Comstock's annual 

 report of the Entomologist in the U. S. Year-book of the Department of Agriculture 

 for 1880: 



Scale of female. — The scale of the female is circular, tiat, with the exuviae laterad 

 of the center ; it is of a pale greyish-brown color ; the exuvise are covered with 

 secretion; the position of the first skin is indicated by a prominence which is pink 

 or reddish-brown. The ventral scale is a mere film which adheres to the bark. 

 Diameter of scale 3 mm. (.13 inch). 



Female. — The color of the female when fully grown is pale yellow with irregular 

 orange-colored spots; oral setae and last segment dark yellow. This segment presents 

 the following characters: There are either four or five groups of spinnerets, the 

 anterior group is wanting or consists of one to four spinnerets, the anterior laterals 

 consist of from seven to sixteen, and the posterior laterals of from four to eight. 



Fig. 9. — English-Walnut Scale. Aspidiotus juylans-regiir. Last segment of female. Greatly 



enlarged. Original. 



There are two or three pairs of lobes. The median lobes are well developed, but 

 vary in outline; the second lobe of each side is less than one-half as large as the 

 median lobes, elongated and with one or two notches on the lateral margin; the third 

 lobe is still smaller and pointed or is obsolete. 



There are two pairs of incisions of the margin, one between the first and second 

 lobes of each side, and one between the second and third lobes; they are small but are 

 rendered conspicuous by the thickenings of the body wall bounding them. 



The plates are simple, inconspicuous, and resemble the spines in form. The larger 

 ones are situated one caudad of each incision. 



The spines are prominent, especially those laterad of the second and third lobes; the 

 fourth spines are a little nearer the first lobes than the penultimate segment; and the 

 fifth are near the penultimate segment; there is also a spine at or near the union of the 

 last two segments. 



Scale of male. — The scale of the male resembles that of the female in color ; it is 

 elongated, with the larval skin near the anterior end; this skin is covered by excretion, 



31 



