CORN APHIS. 
15 
either new to themselves or not observed before over a large district, 
it may be presumed that a much larger amount of it was present 
than usual. 
Attack was reported at various places extending from Fife in 
Scotland to Kent, but the observations were mostly across the northerly 
or north-midland part of England,—Cheshire to Lincolnshire,—and it 
is worth remarking that the inquiries mostly bore date from the last 
days of July to about the fourth week in August : that is to say, in 
fact, that (as far as inquirers or reports showed), the southern counties, 
in which the harvest is the earliest ready for reaping, was the least 
affected by the pest. On the 18tli of August specimens were forwarded 
from Largo, Fife, to show the attack which had recently been doing 
much injury on the correspondent’s farm ; and on the same day, during 
a railway journey from London to Hastings, I noticed a large pro¬ 
portion of the corn-fields in sight from the line had the crop either cut 
or carried. This is of importance relatively to some points of preven¬ 
tion to be entered on further. 
In regard to the kind of Aphis, or “Plant Louse,” which caused 
the damage, some of those which were forwarded, and some of which 
notes were sent, appeared to be of the common Grain Aphis, the 
Siphonophora granaria, Buckton ; but by far the larger proportion of 
the great numbers sent me were entirely brown throughout all their 
stages, and without any of the green in the early stage, or partial 
amount of green in the winged specimens, which is characteristic of 
the true S. granaria . They corresponded more with the A. arena, 
Fab., of which some short description is given in Curtis’s ‘ Farm 
Insects,’ p. 500, and leave the matter consequently in doubt whether 
this so-called “ Oat Aphis ” is not a true, distinct species, or whether 
these dark Aphides were a variety of the variable “ Grain Aphis,” or 
again (following the conjecture sometimes brought forward), whether 
there is a change of colour in the insect with the change of food,— 
from green whilst feeding on the leaves or stem, to the brown colour 
when it has settled in the grain. A large proportion of the specimens 
reached me alive and unparasitised, and it wfill be noticed from the 
following observations that the deep brown or blackish colour was so 
remarkable that this may be a guide next season to those unacquainted 
with the insect, making out its presence on their com. 
About the end of July, infested Wheat-ears were forwarded by Mr. 
G. W. Latham, of Bradwall Hall, Sandbach, Cheshire, with the 
observation that when he gathered them “ they were black with Aphis, 
the appearance being as if the interstices had been filled up with 
‘ smut.’” In this case the infested ears were principally sheltered by 
a high hedge and near trees, and none were found in the centre and 
bottom of the field, where instead of a hedge there was a wire fence. 
