TllK COCCIDAE OF CALIFORNIA. 57 



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

 tliird 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, but its position is marked by a rose- 

 colored prominence, as in the scale of the female; the anterior part of 

 the scale is much more convex than the posterior prolongation, which 

 is flattened. There is a rudimentary ventral scale in the form of two 

 narrow longitudinal plates, one on each side of the lower surface of the 

 scale. Length, 1.25 mm. 



On English walnut, infesting the larger limbs, usually on the under 

 side. 



Aspidiotus perniciosus Comst. 

 (San Jose Scale.) 



Scale of Female. — Circular, slightly convex, 1 to 2 mm. in diameter; 

 gray or dark gray, except the prominent, covered, pale or reddish yellow 

 exuviee. The exuviae are nipple-like, with a shal- 

 low, depressed ring about them, which is quite char- 

 acteristic of this species. 



Scale of Male. — Black in color, rather convex, 

 with the nipple-like prominence and depressed ring 

 still more noticeable than in the female. 



Female. — Two pairs of lobes well developed. Me- 

 dian lobes prominent, rounded at the apex, notched 

 on the outer margin near the middle, though some- 

 what variable and converging. The thickened inner 

 margins of the median lobes extend anteriorly, 

 encircling the anal orifice in a characteristic man- 

 ner. The second lobes are smaller and narrower, 

 though distinct, quite close to the median, notched 

 on the outer margin, pointed and converging. Be- 

 tween the median lobes and bounding each incision of the segment are 

 club-shaped, chitinous processes; the inner usually the larger. There 

 are two conspicuous plates between the median lobes, two caudad of 

 the first incision, and three small, laterally serrate ones caudad of the 

 second incision. Often laterad of second incision are wide, furcated 

 extensions of the margin of the segment. The spines of the ventral 

 surface are situated laterad of the corresponding dorsal spines at the 

 bases of the first and second lobes; the third pair laterad of second 

 5-c 



FIG. 27. .-Ispidiotus 

 perniciosus (San 

 Jo86 Scale). 



