16 
Of the American species, A. forbesi seems most to resemble pernici- 
osus in the form of the lobes, etc., as will be evident from the figures. 
This insect is so far known only from several points in Illinois, and 
Mesilla, N". Mex. It is just possible that it also reached this country 
from Japan, since it was only described last year; but there is at 
present no good evideuce in favor of such a supposition. 
There is a tendency noticeable in our American Diaspidiotm to throw 
off a group with pallid, usually flatter scales, which occur on the 
peripheral parts of trees, the leaves, and even the fruit. Thus, from 
the type of A. ancylus we get A. howardi, I have lately received from 
the Division of Entomology a specimen of 
howardi (fig. 11) out of the original Canyon 
City lot, apparently more adult, and cer- 
tainly better developed, than those Prof. 
Gillette, the collector, sent to me. In the 
^o ^ figure the great development of the second 
o lobe will be noted, so well is it developed 
as to suggest a different species on com- 
parison with fig.-, but I have found similar 
. . ,. differences in the second lobe in coloratus 
(even from the same tree) and uvce. In all 
of the species the second lobe seems to 
vary more or less. The well developed 
second lobe of howardi has led to its being 
confounded with comstocM. This latter in- 
sect, occurring on the leaves of maples, is 
very much like howardi in many respects, 
but is curious for the median and second 
lobes having their tips on the same level 
(fig. 11), or the median lobes even being 
exceeded by the second. This character 
Fig. 11.— AnidiotUM honardi and A. , _ _ , . .. , . , 
eomttoeki (original). 1S found also in the tropical A. destructor, 
which, however, is an Aspidiotus s. str. 
The figure of co'mstocki given is from a specimen on sugar maple, 
Champaign, 111. 
A.juylans-rcgiwis certainly a very distinct form, its scales almost sug- 
gesting a Chry.sompholus. It seems to have been described from Europe 
SLSJuglandis, but I believe it is a native of America, more especially since 
it has a marked color variety (albus) found in New Mexico. 
HABITS OF THE SPECIES. 
It may be said that A.perniciosus mainly affects rosaceous trees and 
shrubs. It is quite bad upon garden roses. Fearing that some of the 
published records might not be reliable, I asked Dr. Howard for a list 
of the food plants on which the scale had actually been seen at the 
