12 
More light is, however, yet needed on this point, as in a recent letter 
received from Baron von Muller, of Victoria, he claims that it could not 
have been imported on Acacia into this State, as all the Acacias in the 
State have been grown from seed. This is a matter upon which I should 
like to have definite information from members of this body, if such 
information is extant. 
It is at present widely distributed in the State, and a very full ac- 
count of its distribution kindly furnished to me by Mr. Matthew Cooke 
shows that there are some ten infested districts, namely, six in the coun- 
ties of Marin, San Mateo, Santa Clara, Sacramento, Sonoma, and Napa, 
and four in the counties of Santa Barbara and Los Angeles. I find that 
it has also obtained a foothold in a few isolated places around San Diego, 
from which it may yet be stamped out. 
FOOD PLANTS. 
A very long list of plants might be enumerated upon which this in- 
sect is either found accidentally or upon which it can live more or less 
successfully. But the list of plants, especially of trees important to us 
for their products, which are seriously affected by it is comparatively 
limited, and will include the Acacias, Lime, Lemon, Orange, Quince, 
Pomegranate, and Walnut. Some few other trees might be added, and 
it is particularly partial to the Rose and the Nettle $ but it is doubtful 
whether the species could permanently thrive and multiply to an inju- 
rious extent on many other trees than those mentioned. 
CHARACTERISTICS OF THE INSECTS. 
The genus Icerya was founded by Signoret, a French entomologist, in 
1875, being based upon the single species , Icerya sacchari (Guerin), which 
lives on sugar-cane in the island of Bourbon. This species and the one 
we are now dealing with are the only two species of the genus, and the 
diagnosis as given by Signoret, and subsequently elaborated by Maskell, 
of New Zealand, is incomplete and does not include the characteristics 
of the male. 
In the report already alluded to I have given a very full character- 
ization of the species in all conditions and stages, but the only facts 
that I need draw attention to on this occasion are, first, that the female 
undergoes three molts and the male two ; i. e ., each has one more 
stage than has hitherto been recognized by entomologists and ob- 
servers $ secondly, that it differs from all other members of its family 
(Coccidm) in its extended powers of locomotion in most of its stages 5 
in its extreme hardiness or power of surviving for a given period with- 
out food, and in its polyphagous habit, or the ease with which it accom- 
modates itself to so great a variety of plants. These are the three char- 
acteristics which most concern you as fruit-growers, and which make it 
one of the most difficult species to contend with. 
