146 QUEENSLAND AGRICULTURAL JOURNAL. [1 Fes., 1900: 
quite short. The use of a roller, under these circumstances, will be especialll 
serviceable when the ground is firm and smooth. ‘The presence of a stroll 
stubble, in the case of a second growth of green fodder having to be dealt 
with, will, of course, too, interfere with its use. A roller, moreover, cannt! 
be advantageously employed at times when it would quickly become cover! 
with adherent soil, for this would produce results somewhat similar to whl 
would be attained were the surface naturally uneven. ._ ed 
5. In many cases, as previously suggested, fields owe their visitation 
caterpillars not to the fact that the moths have earlier deposited their eggs” 
the plants constituting the crops growing thereon that are the object of attacs 
but, on the other hand, to migration of caterpillars from adjacent ones. / 
same remark applies also to different plots in the same field. That this he 
been the case has been shown in many instances in the course of this invest! 
tion. It becomes, therefore, expedient to adopt measures to protect the stl 
unyisited cereal or grass crops. This may be effected by the adoption of 
or other of the following measures:—Surround the infested area with? 
ditch or furrow. If the ground be loose or rubbly in accomplishing 1! 
plough in succession two or more furrows, as deep as practicable, with * 
double mouldboard plough, making the sides as loose as possible by dragg!” 
brush along it. Moreover, should coal tar or gas lime be sprin 
along one of these, a still more effectual barrier will be secured. Whe? 
the soil is, on the other hand, not loose, but sufficiently firm to allow of om 
side of the furrow remaining perpendicular or even overhanging, a standing crop: 
under the circumstances alluded to, may be protected by constructing a spec 
form of ditch such as is described in the following quotation :—‘* The wor 
[writes the late Dr. C. V. Riley] may be prevented, as a general thing, {1 
passing from one field to ante by judicious ditching. It is importath 
however, that the ditch should be made so that the side towards the field to? 
protected be dug under. About every three or four rods a deep hole in, 
ditch should be made, in which the worms will collect, so that they can be ki 
by covering them with earth and pressing it down. They may also be destroy’ 
by burning straw over them—the fire not only killing the worms but render 
the ditch friable and more efficient in preventing their ascent” (Rep?!) 
Commissioner of Agriculture, U.S.A., 1882, page 96). The holes in the ditch 
alluded to trap the caterpillars as they wend their way along the bottom of 
ditch in their effort to pursue their onward march to pastures new; and whe! 
in these an ordinary rammer will despatch them. det 
Experiments on my part have shown that the caterpillar will not eat fodd® 
that has been moistened with a comparatively weak solution of either } ; 
sulphate or copper sulphate (bluestone), even after such fodder has a 
subsequently dried off; or, if it does so—as may happen when the former ‘ 
these reagents has been used—only sparingly so, and with apparent reluctaD® ; 
It may, therefore, prove advantageous, by way of protecting plant growth," 
spray it with one or other of these solutions. The necessity for protect!” 
young maize plants from caterpillars travelling from an adjacent field of wher 
oats, or other cereal seems to afford an instance in which this procedure mig" 
be not only practicable but also successful. However, the pessible injwy ©) 
the plant from the use of too strong solutions must be anticipated. “of 
Again, with a like object in view it will often be found profitable to poe" 
a broad strip of herbage immediately in advance of a travelling host of call ; 
ilars. Paris Green or London Purple may be used for this pun 
ats the former be employed, that bearing the brand of Messrs. Blun 
and Spence, and sold in 1-lb. packets, is recommended in preferey 
to other forms of the article on the market, as having a composi) 
fairly uniform.] These poisons may be exhibited either in water or ‘a 
some dry diluent asa powder. In the former case 1 1b. of Paris Greet al 
i-lb. of London Purple, having been first made into a paste, should be Te 
with 150 gallons of soapy water to which alike weight of fine lime has be a 
previously added (7.e., at the rate of 1 teaspoonful Paris Green to 13 gallo 
ats 
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