54 THE SAX JOSE OE CHINESE SCALE. 



side is a small spine, and two or three such spines are just back of the 

 second lobe, while back of these are three stout teeth curving anteri- 

 orly. A still smaller blunt tooth sometimes occurs near the middle of 

 the lateral maro-in. The seo-mentation of the body at this stao-e is 

 quite distinct. 



2fature female. — After reaching maturity the embr^'onic young are 

 at first not visible, but later the body becomes filled with them. The 

 mature female measures 0.8°"™ wide b}' about 1"'"" long." 



The following description of this stage is reproduced from Comstock: 



The body of the female is yellowish and almost circular in outline; the segmenta- 

 tion is distinct, tho not conspicuous. The last segment presents the following 

 characters : 



There are only two pairs of lobes visible: the first pair converge at tip, are notched 

 about midway their length on the lateral margin, and often bear a slight notch en 

 the mesal margin, near the tip. The second j^air are notched once on tfee lateral 

 margin. 



The margin of the ventral surface of the segment is deeply incised twice on each 

 side of the meson, once between the bases of the first and second lobes, and again 

 laterad of the second lobe. On each side of each of these incisions is a club-shaped 

 thickening of the body wall. 



There are two inconspicuous simple plates between the median lobes, and on each 

 side similar plates extending caudad of the first incision, three small plates serrate 

 on their lateral margin caudad of the second incision, and the club-shaped thicken- 

 ings of the body wall bounding it, and three wide prolongations of the margin 

 between the third and fourth spines. These prolongations are usualh' fringed on 

 their distal margins. There are also, in some, irregular prolongations of the margin 

 between the fourth spine and the penuldmate segment. 



The first and second spines are situated laterad of the first and second lobes, 

 respectively; the third S])ine laterad of second incision, and the fourth spine about 

 one-half the distance from the first lobe to the penultimate segment. " , 



SYSTEMATIC POSITION AND RELATIONSHIPS. 



The San Jose scale was described hy Professor Comstock from 

 material collected in 1880 in Santa Clara County, Cal., on apple, pear, 

 plum, and other fruit trees. ^^ The relationships of this scale insect 

 have been discust b}' vai'ious authors, nota))lv b}' Prof. T. D. A. Cock- 

 erell, without, however, reaching a very good solution, in the judg- 

 ment of the writer. Without going into a detailed technical discus- 

 sion, the San Jose scale is quite as closely allied in structure, scale 

 covering, and habit with the Aonidiella group as it is Avith the group 

 including ancylus and ostrea'fon/ils. It is a ver}" distinct and well- 

 marked species, however, and is always eas}^ of identification after one 

 becomes once familiar with its principal characteristic structural fea- 

 tures, and it is one of the few scale insects which can ordinarily be 



«Rept. U. S. Dept. Agric, 1880, p. 304. 



& Report of the Entomologist, in the Report of Commissioner of Agriculture for 

 1880 (1881), pp. 304, 305. 



