706 Reports of the Honorary Consulting Entomologist. 
garden were infested by wingless females and lice on the under- 
side of the leaves. Likewise a plant isolated from all outside 
attack (of which the ground was treated last autumn to pre- 
vent or destroy lodgment of aphis) has remained quite clean 
from attack. 
When the " fly " came, the acre of plants was infested by the 
pest on the wing like the others. 
With regard to where the attack of " flv " — that is, of aphis 
in the winged state — comes from, there appears to be good 
reason to believe that it comes both from neighbouring hops, 
and also from damsons and sloes, which, from specimens sent to 
me as early as March and onwards, I find to be infested with 
the variety of hop aphis considered by many entomologists to 
infest both hops and various kinds of plums. On June 28th I 
received from Wateringbury, Kent, freshly gathered sloe-sprays 
loaded with aphides, which, after long and careful micro- 
scopical comparison with the true hop aphis, I consider to be 
the hop-damson aphis, Phorodon hnmuli, var. Malalieb. 
I think, therefore, that it is very likely indeed that a portion of 
the attack comes on the wing from sloes and damsons, but by no 
means all, as there are differences in form (as far as I see) in 
these two kinds or varieties : and from information sent in 
up to this date it appears to me that if, as far as hop-grounds 
go, measures were taken to prevent the hills being in- 
fested when the aphides are leaving the hop-bines in autumn, or 
were so treated by dressings laid on them in the spring that the 
hop aphis could not crawl vp through the application, that it 
would make a great difference in the amount of first attack, 
and necessarily diminish the amount of hop " fly " that would 
be produced on the bines. 
But, further, I certainly consider that the complete removal of 
sloe hedges, and also, where damsons are grown, dressing over the 
ground beneath them as suggested above, would be very likely 
indeed to lessen the amount of these pests on the hops near. 
In experiments which I have tried in my own garden, I have 
found that a good sprinkling of gas-lime in spring, on the surface 
of the ground through which the hop-shoots were coming up, 
did no harm at the lime, and the plants are growing well now. 
Experiments are in progress relatively to additions to the 
usual soft-soap washes which may be of use, and which will be 
reported ; but, as far as appears at present, it is prevention by 
treatment beforehand that needs working out, for remedies are 
necessarily both enormously expensive and not always of service. 
With regard to ox warble-fly, excellent communications are 
being sent in, and arrangements being made for further ob- 
servations and reports on the few points still needed. 
