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Many experiments were made to ascertain, if possible, what sub- 
stances could be economically introduced into the soil infested with 
white grubs which should destroy them, while not injuriously affecting 
the crops. Although the results reached were less definite and satis- 
factory than were desired, it may be worth while to state some of them 
as briefly as possible. Several of the larve infested with Cordyceps 
were placed in a box of sandy soil and such conditions preserved as 
were thought favorable to the development of the fungus. Healthy 
larvee were also placed in this box. The fungus did not develop spores 
and the uninfested larve were not attacked during the time of the 
experiment, but this may not have been sufficient for the production 
of the desired result. The accounts of Prillieux and Delacroix in 
Compte Rendus, May 11, 1891, show that the European Melolontha can 
be successfully attacked by a fungus, and culture tubes are offered 
for sale. 
Freezing the earth even when the degree of cold was not below zero 
F. destroyed all contained larve. This is remarkable because, as has 
been noticed, active and apparently healthy grubs were found in 
frozen earth in the field. In the boxes, however, they did not with- 
stand cold very much below freezing. Experiments were made to 
ascertain the possibility, or feasibility, of starvation, with the result 
that very few larve were affected even when kept for months in soil 
more free from organic matter than that of any cultivated field would 
be, and it does not seem at all probable that this method, which has 
been recommended by some of our best entomologists, is of any value. 
A dry soil is very unfavorable to the larve, and if very dry they 
speedily perish. On the other hand, they are not unfavorably affected 
by a moist or even very wet soil, at least for some time. 
Several of the potash salts were used in the form of strong solution, 
1 ounce in 1 pint of water and poured over soil containing larve. The 
results were not such as to recommend the use of these salts, although 
they are far from valueless. The sulphate of potash on the whole 
proved most useful, but to destroy any considerable portion of the 
grubs an amount larger than would generally be economical was neces- 
sary. Common salt and wood ashes were each tested both in solution 
and as lye and mixed with the soil dry, but the grubs were not seri- 
ously injured by them. Bisulphide of carbon was more effective and 
without doubt could be used to advantage in many cases. Kerosene 
emulsion, however, is better in its results as well as cheaper and seems 
on the whole decidedly preferable to any substance tried. .Poured over 
grass in dilution such that the grass was uninjured, it yet destroyed 
most of the larve. Red ants are a great aid in destroying the grubs, 
and very likely other species than that noticed, the common red ant, are 
equally valuable. A box in which a number of the larve were living 
having been discovered by the ants they at once took possession and 
promptly destroyed every one of them, and this leads to the conclusion 
st 
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