Pa ed ~% ? 7" “ 
“EXTRACTS FROM CORRESPONDENCE OF THE DIVISION. 31 
observations I have noticed that leaves which spiders had folded or webbed together 
 - for their nests or lairs almost always proved infested with seale, if infested trees 
were found in the neighborhood. This I was at first inclined to attribute solely to the 
_ protection from enemies and parasites afforded by the web and presence of the spider. 
No doubt, where the source of infection is near at hand, this may give a sufficient ex- 
planation of the observed facts. Lately, however, I have been examining with great 
eare a lot of one and two year old trees which I set out myself last March. The 
stock from which these trees were taken was to my certain knowledge almost abso- 
lutely free from scale insect. At the time of setting, the weather was excessively dry 
and unfavorable; in consequence of which the trees, 600 in number, were badly 
; checked, and to a great extent lost their tops and nearly all their leaves, so that the 
present growth is all new, produced during the past summer. Notwithstanding, I 
find to my surprise, scale insects beginning to appear on a large proportion of the 
plants. Upon some of them the insects have begun to spread over the branches, and 
the exact spot where the trouble began is no longer ascertainable. In a strikingly 
large number of instances I find two or more leaves bound together with silk and 
occupied by a spider, and the inner surfaces of these leaves completely coated with 
scale insect, when not a trace of the insect can be found elsewhere upon the tree. 
Furthermore, this lot of trees occupies a position west and north of the remainder of 
the grove, in the path of the prevailing [S. E.] winds. The adjoining rows of older 
trees, on the southeast, are many of them quite badly infested with, for the most 
part, chaft-scale (Parlatoria pergandii), there being usually a relatively small number 
of long-scale (Mytilaspis gloverii) mixed with the other species. As is often the case, 
the proportions of this mixture of species remains quite constant throughout the in- 
fested part of the grove. Now, I find in the newly-infested young grove these two 
scales mixed in about the same proportions, so that no doubt exists in my mind as to 
the source of their infection. As to the manner in which it has been accomplished, I 
submit that if, as many persons think, the young lice are transported bodily by the 
winds, we would have had a very different distribution from that Which exists upon the 
older trees. The larger and heavier young of the chaff-scale would have been car- 
ried to a less distance and in smaller numbers than the long-scale. (There have been 
no unusual storms or very high winds during the past summer.) Again, in a chance 
distribution by the wind I can see no reason for any evident connection with spider 
web shelters such as I have mentioned. Individual scale larvie do not, as far as I 
have observed, wander far in search of such protection, and do not need it until the 
colony becomes sufficiently numerous to attract enemies and parasites. The part 
played by winds is evidently a secondary one, inasmuch as nearly all the web-inhab- 
iting spiders make use of the wind to carry themselves and their bridges of web from 
tree to tree, and the spiders transport as passengers upen their bodies the migrating 
larve of the scale insect.—[H. G. Hubbard, Crescent City, Fla., September 22, 1882. 
THE SEVENTEEN-YEAR CICADA IN NEW YORK. 
I have deferred complying with your request to furnish you with data in regard to 
the extent of the seventeen-year locusts, in order to obtain all possible information 
on the subject in this section of the country. My means of obtaing data in this 
matter are quite limited, and, therefore, I can only furnish you with the following: 
‘There are two districts in this county (Yates), the towns of Torrey and Middlesex 
where these locusts were prevalent in great numbers during a part of June and July. 
‘Their extent in Torrey covered an area of about four square miles, and in Middlesex, 
somewhat less. These towns or localities are situated at some distance from each 
other, one bordering on Seneca Lake and the other on Canandaigua Lake. Middle- 
sex is situated on the western boundary of the county, and Torrey on the eastern 
boundary. Iam also informed that these insects were prevalent in portions of the 
counties of Ontario, Livingston, and Wyoming, of western New York. Iam not able 
to learn that they made their appearance in any other parts of the State. They con- 
