99 
Multiplying generation after generation throughout the season, 
' each new generation, under favorable circumstances, soon itself 
imencing to multiply, it is easy for a species ordinarily quite 
Lgnificant suddenly to burst its bounds, if conditions become tem- 
arily never so little favorable, and to appear in overwhelming 
nbers, inflicting extraordinary damage. It is therefore unques- 
lably well that strawberry growers should know that their plants 
subject to such attacks; and they should likewise unquestiona- 
be able to recognize these insects when they occur in their 
Is, and should be made acquainted with the measures needed to 
train them, provided any such sudden and destructive outbreak 
es place. 
i 
LITERATURE. 
Si 
'he first mention of the occurrence of any plant-louse on the 
nwberry in the United States, which has come to my knowledge, 
sontained in the Rural World of December, 1675, where Prof. 
?y briefly characterizes a variety of Siphonopliora fragarics, Koch, 
‘ter the name of immaculata, and reports its occurrence in West- 
Missouri. Next, in the second bulletin of the Illinois State Labo- 
>ry of Natural History, published in 1877, Dr. Cyrus Thomas, 
a State Entomologist of Illinois, in a list of the plant-lice of the 
te belonging to the tribe Aphidini, merely mentions a green 
it-louse upon the strawberry, which he assigns to the above 
eies. In his report as State Entomologist, for 1879, Dr. Thomas 
iffy treats this plant-louse, translating the original description of 
*h, and adding, “This species feeds upon the strawberry plant, 
acially the under sides of the leaves and the stalks of the unripe 
t._ A species which I presume is identical with this has been 
isionally observed on strawberry plants in this State, but so far 
iave been unable to procure specimens. In 1875, Prof. Riley 
dved from Mr, W. W. Hopkins, of Kansas City, specimens of a 
it-louse which was injuring his strawberry plants. From a copy 
lis notes on these specimens, which was verv kindly sent me, I 
n that they differ from Koch’s description in wanting the spots 
the sides of the abdomen in the winged female, and in the head 
he wingless female being yellow; yet he decides without serious 
bt, that they belong to Koch’s species. He names this variety 
laculata. 
he next reference to a strawberry plant-louse is that contained 
i paper* by Prof. Riley and Mr. Monell, published in the same 
c, in which the latter indicates the peculiarities of the variety 
laculata, and expresses the opinion that it is possibly a distinct 
dies. 
f --- 
'Jotes on the Aphididac of the United States, with Descriptions of Species Occurring 
of the Mississippi. Bulletin of the United States Geological and Geographical Sur- 
’f the Territories, 1879, Volume V, Number 1. 
i 
