2 
HOP APHIS. 
them towards the top of the plant; secondly, observations are given 
of the Hop Aphis occurring on Plum and Sloe. 
Observations are likewise given as to Hop Aphides and their eggs 
not having been as yet found in winter shelters, also on Hop Aphis having 
been found on Nettle. 
An important observation is given of Hop Aphis appearing on a 
plant which had been enclosed carefully from outside attack. 
There are also notes on benefit from healthy growth ; from washings; 
and from presence of Ladybirds. 
Still, however, it appears to me that the only method by which we 
can make absolutely sure whether Lice come up from the ground or 
not is by isolating Hop plants. This isAhe way in which the history 
of the Vine Phylloxera was completed, and, though there would be 
difficulty in elaborate arrangements, there would be little trouble in 
the method noted at p. 10, of fastening three poles together at the top, 
and enclosing the plant within with stout muslin, so early in the year 
and so securely that there could be no entrance from outside. So we 
should know what was happening. 
At present nothing is proved, but there is no doubt that Aphis attack 
is considered by most of the contributors of the following notes to 
appear first as “ Fly.” 
With regard to what plants these “Flies,” i.e., winged Aphides, 
come from, it may be from Plum or Sloe, or apparently it may be from 
Nettle. I have had opportunity of making sure, through the assistance 
of Mr. G. B. Buckton, F.R.S., that specimens of Aphis on Plum 
leaves were the same kind as the Hop Aphis; and also specimens of 
Aphis were sent me on Nettle leaves, which I could not find differed 
in any way from Hop Aphis.* 
Observations of the First Appearance of Hop Aphis as “Fly,” 
AND ON THE UPPER PART OF THE PLANTS. 
The following communications give observations of the Hop Aphis 
being first observed as Fly, i. e., winged; also of attack beginning on the 
outside of the gardens, when the wind is from a cold quarter ; and that 
ground exposed to cold winds, or cold and damp, are found to suffer. 
Dr. Chapman’s note regarding larger wingless Aphides being 
observed by him in 1882 amongst a large number of small ones, is 
* The reader will please observe that, though the common English names are 
used for convenience, I am not confusing the various sorts of Aphides. By the 
Hop Aphis throughout I mean the Aphis (Phorodon ) Humuli or the Aphis (Phorodon) 
Mahaleb (which may be a variety, but if not, is the same as the A. Humuli) ; and it 
is this A. Humuli or A. Mahaleb which I allude to as having occurred on Plum and 
Nettle. I am not referring at all to Aphis Pruni, nor to Aphis Urticaria, nor to 
Aphis (Siphonophora) Urticce, or any other Aphis of the Plum or Nettle, only to the 
Hop Aphis. 
