COCCIDAE OF OHIO. 75 



liei.nai'ks : This is undoubted iy a cosmopolitan species and 

 has been described under various names in several countries. 

 The scale is popularly called the "Appletree Bark Louse," 

 though not confined to apple trees. Perhaps the greatest damage 

 is done on Poplars and Willows. In the northeastern part of Ohio 

 this scale is plentiful, and in instances many Poplars have been 

 killed by its attack. This is a difficult scale to combat, but the 

 same measures as used for the San Jose' Scale will prove suc- 

 cessful. 



Genus PAPtLATORIA Targ. 

 The two species which are reported for Ohio are both green- 

 house species, or rather in this case P. zizypJius (Lucas) was 

 found on oranges and lemons in the Columbus markets. Parla- 

 toria 'pergandii Comst. aifects Citrus trees most seriously. 

 A. Scale of female circular pergandii 



AA. Scale of female elongated, black zizyphus 



FarUitoria pergandii Comstock. 

 Fig. 24. 



p. pergandii Comst., Rep. U. S. Dep. Ag., 1880, p. 327 (1881). 



P. pergandii Comst., 2nd Rep. Dep. Ent. Corn. Univ., p. 113 (1883). 



Scale of female: Circular to elongated, irregular, dirty-gray, 

 1.6 mm. in length; exuviae marginal, brown, the first naked and the 

 second covered by a thin film of secretion, occupying nearly one-third 

 of length of scale. 



Scale of male: Long and narrow, lateral margins prominent, not 

 carina ted, light gray with terminal exuvia darker. 



Female: Three pairs of well-developed lobes, nearly equal in size, 

 broadest near the middle tapering anteriorly, notched deeply on each 

 side near the apex. A rudimentary fourth lobe, produced into a 

 papilla, half-way between third lobe and penultimate segment. A 

 crescent-shaped thiclvening of the body-wall appears between the 

 median lobes, between median and second, second and third, and two 

 thickenings between third and fourth lobes and between fourth lobe 

 and penultimate segment. The plates are as long as the lobes and 

 fringed on the distal margin. Two between median lobes, two between 

 median a.nd second, three between second and third, three between 

 third and fourth, and three palmate plates cephalad of fourth lobe. 

 On the three segments preceeding the last, are five or six plates, each 

 produced into a .papilla. A spine on the dorsal surface of each lobe 

 near the margin; on the ventral surface, the spines are situated laterad 



