Reports of the Honorary Consulting Entomologist. 699 
Experiments on this point are being carried on with lime, 
lime and salt, and also with ashes sprinkled with paraffin ; and 
I am myself trying the effect of spent gas-lime (that is gas-lime 
which has been exposed for about eight months), applied as a 
thin layer on the ground, around the pushing shoots, and I do 
not see that any injury has been caused by it. 
With regard to the attack which is considered (and, as far as 
I can judge, with much reason for this opinion) to come on the 
wing later in the season to hops from damsons and sloes, there is 
great need of more precise information, and it would be very 
desirable to have specimens forwarded for minute examination 
as soon as the " fly " appears on the upper part of the hop 
shoots. 
The true hop aphis, the Phorodon humuli, is well known, and 
under the microscope is distinguishable by the lowest joint of 
the horns being bluntly toothed or gibbous, and also by the 
tubercles on the forehead having a tooth on the inner side. 
The Phorodon humuli, var. Malaheb, is recorded as being 
found on damsons, sloes, and plums, and is considered by many 
qualified observers to migrate from damsons, &c., to hops — there- 
fore to save trouble I call it here the " damson-hop " aphis. 
This much resembles the true hop aphis, but is described scien- 
tifically as not having the tubercles on the forehead so much 
developed as in the case of the wingless viviparous female. 
There is great difference of opinion as to which genus of aphides 
this kind should be placed in, and from specimens sent me I 
incline to think that the characteristics, so far as amount of 
forehead tubercle are concerned, are very variable, but it may 
be distinguished from two other kinds which often infest plums 
or damsons as follows. The viviparous females are green, 
whereas those of the Myzus cerasi, often found on cherries and 
plums, and of which the pale lice in their early state much re- 
semble hop-lice, are wholly Hack, saving an occasional clouding 
with green. 
The Aphis pruni, or common plum aphis,* is, as far as I see, 
always without frontal tubercles. I mention these points as 
some guide to observers who wish to enter on them, but at the 
same time beg to submit that what we most urgently want just 
now is plain practical experiment. It is certain that hop-lice 
(irrespective of their scientific names) have been clearly seen in 
many different localities, being deposited by wingless females, 
and it is of some importance to notice that these were first 
observed by a well-skilled grower, but (though numerous) had 
* The above characteristics are mainly taken from the ' Monograph of Britisli 
Aphides,' by G. B. Buckton, F.K.S. 
