11 
the ci’op too often dies. If we had distinct experiments 
on the direct effects on insect life of nitrate of soda, 
kainite, guano—which is said (whether rightly or not I 
do not know) to destroy some larvae, and also those of 
gas lime or alkali-waste, we should then have some¬ 
thing to fall back on in the way of information when 
attack came, which could not fail to be of service. 
We all know that wireworms are attracted by rape 
cake, but what is the special method of action of the 
kind known as Kurrachee, or Indian rape, really 
mustard cake ? When in my own experiments I have 
limited the wireworms to food consisting of little but 
one of the above two kinds of cake, I found that 
although the larvse in the mustard cake fed as greedily 
as the others for a time, yet in about a fortnight they 
died ; and although when they began to perish I placed 
other food in their reach, they appeared past recovery 
and did not touch it. 
We know that mustard is a good clearing crop, a 
good means of getting rid of .wireworm, and in experi¬ 
ments with the cake I found that the wireworm would 
not enter it until the pungency which follows on mixing 
this mustard cake with water was gone off, and I would 
suggest that enquiry into the precise method in which 
mustard is obnoxious to wireworm would Joe very 
useful. 
If this matter was fully investigated we might find 
that by a more frequent introduction of mustard into 
the rotation of crops we not only cleared the land of 
wireworm, but on suitable land secured a paying crop 
of mustard free from the ravages of the mustard beetle, 
which is too apt to become a ruinous scourge to this 
crop in districts where its cultivation is widespread and 
continuous. 
Time does not allow me now to enter on full details 
of prevention of the pest we are especially considering, 
but I wish to draw your attention to its absence some¬ 
times following on the application of seaweed being a 
matter worth enquiring into, as in this case we have the 
advantage of a manure often procurable at small cost 
which contains the alkaline and nitrogenous and mineral 
constituents we have seen are generally serviceable, 
joined in some eases to an amount of salt distasteful, to 
say the least, to the wireworm. 
The mechanical measures by which attack may be 
checked by means which will consolidate the surface, 
and so prevent the wireworm travelling through the 
soil, are of great importance. We find notes of them 
in their adaptation to different soils, and different con¬ 
ditions of the land caused by weather influences, from 
the slight pressure given by driving the lightest sheep 
that can be put on, over the field, to the heavy treading 
of cattle; and the amount of pressure by weight of 
roller varies similarly from an ordinary light field roller 
to the Cambridge ring roller, or Crosskill’s clod crusher. 
For these and many other points of detail I must 
refer you to the paper recently published in the Journal 
of the Eoyal Agricultural Society, compiled from notes 
furnished relatively to wireworm prevention by some of 
