JUNIPER SCALE-INSECTS. 



915 



14. The juniper scale insect. 



Diaspis earueli Targ. Tozz. 



This scale insect is said by Professor Comstock to be. very common 

 at Washington, D. C, on various species of juniper and allied plants. 

 Its numbers are reduced by a chalcid parasite, Aphelinus mytilaspidis 

 Le Baron. The following account is by Comstock, and is copied from 

 the U. S. Agricultural Report for 1880 : 



Scale of female. — The scale of the female is circular, snowy white, with the exuvise 

 central or nearly so, naked, and yellow. Diameter of scale, 1 to 1.5™™ (.04 to .06 

 inch). Figs. 2, 2a, 2b. 



Female. — The females are yellow, circular in outline, a little elongated posteriorly. 

 The last segment of the body presents the following characters : 



The anterior group of spinnerets consists of about eight, the anterior laterals of 

 from ten to sixteen, and the posterior laterals of about eight. 



There are four lobes which are nearly in a straight line, the end of the body being 

 truncate. These lobes are quite small, rounded posteriorly and are equidistant from 

 each other. The second lobe of each side 

 is deeply Incised, but the lateral lobule is 

 very small and in many cases concealed by 

 the margin of the segment. 



Each lateral margin of the segment is 

 divided into three subequal, more or less 

 distinct lobes, each lobe ends posteriorly 

 in one or two lobules, each of which bears 

 an elongated pore on its dorsal surface. 



The plates are short and in some cases 

 subtruncate at extremities; they are sit- 

 uated as follows : two between median 

 lobes; two inconspicuous ones laterad f 

 first lobe of each side ; two laterad ci 

 second lobe ; usually one on the anterior 

 part of the first lobe of the lateral margin; 

 one or two near the middle of the second 

 lobe of the lateral margin, and two or 

 three on the third or anterior lobe of the 

 lateral margin. 



The spines on the dorsal surface are sit- 

 uated as follows : one upon the first lobe 

 near its lateral margin ; one on lateral 

 lobule of the second lobe ; and one a short 

 distance mesad of the mesal plate of each 

 of the three lobes of the lateral margin. 

 On the ventral surface the spine accom- 

 panying the first and second lobes of each 

 side are obsolete. There is one at the base 

 of the plate of the first lobe of the lateral 



margin ; one between the plates of the second lobe, and one near the middle of the 

 third or anterior lobe of the lateral margin. 



Scale of male. — The male scale is white and very small, being only 1™™ (.04 inch) 

 in length ; it is elongated, with a prominent median ridge ; the larval skin is naked 

 and light yellow in color. See Fig. 2b. 



^<in M 



Fig. 303.— The juniper scale-insect From 



Comstock. 



