Spraying for the Alfalfa Weevil. 19 
senate of lead and arsenite of zinc have been used on a large number 
of fields with complete success, and it is likely that other arsenical 
poisons which are recommended for orchard spraying are equally 
good. There is practically no danger of burning the foliage of 
alfalfa, and therefore the range of suitable poisons is larger than in 
fruit-tree spraying. The principal considerations are the cost of 
the poison and its capability for sticking to the leaves, and in both 
these respects arsenate of lead is shghtly superior. 
The dry, powdered form of the poison is better than the paste, 
because it costs less to ship and keeps better from year to year. 
The poison is made much more effective by adding soap to make 
it spread more readily and stick to the leaves, which are so hairy 
that the particles of spray tend to collect in larger drops and run off. 
The poison is weighed or measured for use at the rate of 2 pounds 
of the powder or 4 pounds of the commercial paste for each 100 
gallons of water, and is stirred with a little water in a pail until it 
becomes a thin paste without lumps. It is then diluted and strained 
into the tank through brass milk-strainer gauze, which may be 
mounted for the purpose on a hoop or a frame which fits the opening 
in the tank. Two pounds of laundry soap for each 100 gallons is 
added. 
The materials and utensils should be kept free from dirt and lint, 
which might later cause clogging of the nozzles, and when cloth is 
used for straining liquids or covering containers it should be canvas 
or muslin and not a linty fabric like burlap. The spray liquid should 
be mixed just before use and kept stirred up until it is all used, to 
prevent the settling and wasting-of the poison and the clogging of 
the pipes. 
3 APPLICATION OF THE SPRAY. 
The spray outfit is ready for work when the tank, pump, pipes, 
and nozzles have been cleaned and, together with the engine, tried 
and found to be in working order and regulated so as to deliver 100 
gallons of spray mixture per acre and maintain a pressure not lower 
than 75 pounds. 
The weather most favorable for spraying is at the beginning of a 
warm period, because in warm weather the larvee feed more freely 
and it is desirable to have them do so for several days immediately 
after the application of the poison. If it is put on just before a cold 
spell the weather may cause some of the feeding to be postponed until 
the alfalfa has grown a few inches and provided fresh unpoisoned 
food for the larve. Nevertheless, good results have usually been 
obtained in spite of unpromising weather, and all that is necessary 
is to give the poison a chance to dry thoroughly upon the foliage be- 
fore it is exposed to storms. 
