In furious T ipulidce. 
103 
Preventive and Remedial Measures. 
Although there is no known remedy for “leather-jackets” in the 
field there is much we can do to lessen the amount of harm 
caused by them and to prevent their undue increase. In garden 
cultivation, on the other hand, we can destroy them even in the soil, 
if it is considered worth the while. 
In the first place, we can do some good in preventing egg laying. 
This we may do in three ways; firstly, by keeping down all long 
herbage during the autumn, long rank growths at the headlands and 
along hedgerows ; secondly, by bush-harrowing pasture land or 
heavily rolling the same when the swarms of flies are noticed in the 
fields, hundreds will thus be killed and so prevented from laying 
their eggs, and the eggs in many cases themselves will be destroyed ; 
thirdly, late mowing and rolling of lawns, croquet grounds, etc., will 
not only kill large numbers of the adults, but eggs as well. There 
is no doubt that for preference the flies will go to damp areas to 
deposit their eggs, and thus drainage will do good. This has been 
carried out on many occasions and has always been attended with 
good results. Pasture land and clover lay should be broken up 
when possible early in the autumn, so that the flies can find no 
shelter amongst which to lay their eggs. The land may first be 
dressed with gas lime, spread over it at once and allowed to remain 
on the surface for a few days. The smell would deter the flies from 
laying their eggs and would probably affect any small larvae present. 
The effect of gas lime is very variable, however, and it is doubtful 
from recent experience if it has much effect upon large subterranean 
insects. 
The old plan of “ paring and burning ” the stubble or grass on 
breaking up pasture is perhaps the best method of clearing out this 
and other ground pests. It of course has its disadvantages and is 
now seldom practised, but there is not the least doubt that it is the 
only way to lessen these pests in the soil. 
Rolling with a cross-kill or Cambridge ring roller does some good 
by compressing the soil, and so preventing the “ leather-jackets ” 
from free movement in the ground. This is especially advantageous 
where they are attacking wheat or barley. In dealing with their 
life-history it was pointed out that the grubs come to the surface at 
night ; a heavy ring-roller, of course, would kill any number of their 
larvae if passed over them, and could not fail to do much good, 
