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tion of crops or other measures which often really involve a greater 
outlay or loss, he dislikes to adopt measures unfamiliar or involving 
special study which may be really effective. In general it may be said 
that root-infesting species are protected from direct attack in the 
destructive stages. While it has been shown that such larvae may be 
destroyed by the use of kerosene emulsion, such applications in quan- 
tities sufficient to destroy the larvae beneath the surface of the ground 
would not be considered of general practicability. Many of these 
species however may be attacked at other stages. Nociuids and Pyra- 
lids are attracted by lights, and some of them certainly prior to egg 
laying, so that for certain species trap lights may be recommended. 
Elateridae may be destroyed in the adult stage by the use of arsenical 
baits: Lachnosterna may to some extent be affected by spraying the 
trees with arsenical solution, and some of the root-infesting Aphids by 
the destruction of their spring generations on woody plants. For the 
species feeding upon the stems, leaves, and seeds of plants, applications 
must depend upon the insect and the nature of its attack. In some 
cases, we believe a broadcast spraying of the arsenites for leaf-feeding 
species and of kerosene emulsion for suctorial species might be applied 
with profit. For grasshoppers and leaf hoppers the use of the tar pan, 
a method which has proven very successful, may be recommended. 
This process is perhaps worthy of most extended recommendation, 
and there can scarcely be a doubt that its general adoption upon pas- 
ture and meadow lands would result in great profit. It is also quite 
certain that for many species eggs are laid in the grass in autumn, and 
late fall or early spring burning will prove of great advantage if condi- 
tions will permit adoption of this plan. 
In the most general way, therefore, we may recommend — 
(1) A general rotation of crops, especially for clover and for meadows 
generally, and change at the end of four or five years at the most. 
(2) Where it is desirable to keep the same field continually in grass 
or for a long series of years, as in rough land or woodland pastures, 
attention to the maintenance of trap lights, the use of arsenical baits 
or applications, burning, and the tar pan should be practiced, especially 
after the second year. 
(3) To allow ground squirrels, moles, and other natural enemies to 
carry on their work unmolested, and in case their multiplication 
affects surrounding crops to adopt means of protecting such crops 
without destroying these animals. If in localities where fertilizers 
may be used with profit, to adopt the use of such kinds as may have 
insecticidal properties. 
