NURSERY PRACTICE FOR PRAIRIE-PLAINS PLANTING 137 



This bait should be spread thinly and evenly at the rate of 10 

 pounds (dry weight) per acre, or more heavily if the insects are very 



numerous. It should fall into flakes when scattered with the hand 

 and in tins form will be safe for use. If left on the ground in lumps 

 there is danger that livestock will pick up the poison. As the mash 

 dries it becomes less attractive, and it is necessary to apply it when 

 the grasshoppers are starting their first feeding of the day, usually 

 early in the morning. In the case of migrations the hoppers may feed 

 at almost any time where food is found. Spread the bait on a clear 

 day. preferably when the temperature is between 70° and 85° F. 



A mixture of half bran and half sawdust, or better, 60 percent 

 bran and 40 percent sawdust, can be substituted in the above formula, 

 but this mixture is not always as satisfactory as bran alone. Most 

 sawdusts are suitable if they are fairly fine and a year or more old. 

 Although fresh sawdust from cottonwood can be used, fresh pine saw- 

 dust is not suitable. Two quarts of liquid sodium arsenite (4 pounds 

 per gallon material) or 2% pounds of dry sodium arsenite can be substi- 

 tuted for the 5 pounds of crude arsenic. Five pounds of paris green 

 can also be substituted, but this is much more expensive. Calcium 

 arsenate, sodium arsenate, or lead arsenate should not be used. 



CATERPILLARS 



Caterpillars are the larvae of butterflies and moths. They are 

 wormlike, smooth, spiny, or hairy, with 3 pairs of true legs and usually 

 5 pairs of false or prelegs, including the anal pair. 



Insects of this group can be readily controlled by applying a spray 

 of lead arsenate mixed in the proportion of 1% to 2 pounds (powdered 

 form) to 50 gallons of water. Other arsenicals such as calcium arsenate 

 or paris green may be used, but with them there is greater danger of 

 burning the foliage. A sticker such as fish oil or linseed oil, at the 

 rate of 4 ounces for each pound of lead arsenate, will make the poison 

 adhere to the foliage and give protection for a longer period. 



BLISTER BEETLES 



Blister beetles are of medium to large size, slender, with the portion 

 between the head and wing covers (the prothorax) narrowest. The 

 body and wing covers are comparatively soft. The color may be 

 black, grayish, tan, or some other shade, either plain, spotted, or 

 striped. Only the adults feed on the foliage, and they infest a variety 

 of plants. In the nurseries certain species prefer Siberian pea-tree 

 and locust foliage, although other seedlings may also be attacked. 

 These beetles are distributed over the entire plains region. The 

 larvae of some species feed on grasshopper eggs and therefore are 

 beneficial in this stage. 



Spraying the foliage with 1% pounds of lead arsenate to 50 gallons 

 of water will protect the seedlings, largely by repelling the beetles, 

 although some will be poisoned. As the new growth conies otit beetles 

 will return to feed on this portion, and it will be necessary to spray 

 several times to give good protection. The use of a sticker in the 

 spray is not advisable where these repeated applications are made. 

 Sodium fluosilicate applied as a dust has given good control of certain 

 species, but there is some danger of burning the foliage. 



