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inadvisable that a field which is badly infested one year, should 
be planted to corn the next. 
General Prevention. —The principal and most effective preventive 
measures of general promise are those for the collection and de¬ 
struction of the June beetles before they have laid their eggs.. 
They are practically confined to the following four methods, men¬ 
tioned in the order of their importance: (a) shaking and jarring 
down the beetles at night from the trees in which they feed, and 
their collection on sheets or cloth-covered frames similar to those 
in use for the peach and plum curculio; (b) exposing light traps 
early in the evening in places frequented by the beetles; (c) the 
spraving of trees to which they resort, with Paris green or other 
suitable insecticide; and (d)‘ the turning of pigs into wood¬ 
lands, forest plantations, and the like, where the June beetles 
conceal themselves by day. 
These are all measures calling for cooperative action by all, or 
at least the greater, part, of the farmers of a neighborhood r 
since it is useless to expect any pronounced effect from isolated 
and individual action. They can only be carried out by previous 
agreement of those interested, by the offer of premiums for the 
beetles, or by the passage and enforcement of laws bearing- 
equally upon all. In estimating the value of these methods it 
should be remembered that each female beetle is the average 
equivalent of a large number of grubs. 
In illustration of the effectiveness of the first mentioned of 
these methods, I quote from notes of Assistants Marten and 
Hucke, made in 1891. 
May 19, 2:40 a. m. Shaking the trees in the university forest 
plantation made the beetles fall very easily, the second shake 
generally getting all, or nearly all, there were in a tree. Those 
shaken from the trees made no effort to fly up again, and only 
one such came to the lantern trap near by. 
3:45 a. m. The beetles apparently as abundant as ever on 
butternut and hickory. The lightest shake of either of these 
trees brings down the beetles by dozens. Butternut trees six to 
eight inches in diameter drop them in considerable numbers when 
shaken by the hands—so easily are they detached. 
From other notes it is apparent that the June beetles cling 
more closely to the trees early in the evening—from eight to 
ten o’clock,—a fact doubtless to be connected with the gradual 
stupefying effect of the night dews and the cooler air towards 
morning. 
This is the standard method in both France and Germany for 
the control of injuries by the European white grubs. The re¬ 
sults attained in the former country are shown by an article, 
“La Chasse aux Hannetons,” published in the Revue de deux 
Mondes for 1878. In consequence of an offer of premiums for 
beetles in the department of Seine-Inferieure, 1,149,000,000 of 
these cockchafers were collected and paid for in that year, at an 
—9 E. 
