88 THE REPOET OF THE No. 36 



are predaceous on the eggs of grasshoppers. It is well, therefore that the farmer 

 should realize this and watch for the appearance of blister beetles in years fol- 

 lowing excessive outbreaks of grasshoppers. Whenever these latter insects appear 

 in destructive numbeers^ the now well-known Griddle mixture f should be applied. 

 This has given excellent results particularly in Manitoba and the west. Wlien 

 the grasshoppers are destroyed in this manner, the chances are, of course, that 

 blister beetles will not be present in numbers to do very serious damage the fol- 

 lowing year. When spraying crops with an arsenical mixture for the destruction 

 of blister beetles it is important that the mixture be applied immediately their 

 presence is detected, on account of the voracious habits of these insects. Paris 

 green, the insecticide which has been mostly used, can be applied either as a spray, 

 using one ounce to every ten gallons of water, to which has been added an equal 

 quantity of freshly-slaked lime, or as a dry application mixed with from 10 to 30 

 parts of flour, land plaster or slaked lime. Plants with such coarse foliage as the 

 potato will stand double the above strengths of Paris green. In some outbreaks 

 it may be necessary to repeat the application, as the beetles which are killed are 

 soon replaced by others. 



Blister beetles are very easily disturbed and for this reason a remedy which 

 has often been very successfully employed is for two or three boys, or more if 

 necessary, to walk through an infested field and wave from side to side boughs of 

 spruce, or other branches. Such an operation will drive the beetles ahead of them 

 and when the insects come to the edge of the crop they will disperse and seldom 

 return. This method has given excellent results in outbreaks of the Western 

 Blister Beetle. This latter species is particularly ravenous and is capable of de- 

 stroying a crop in a very short time, even in a day according to some reports. 

 In such instances, of course, spraying would be of little avail. In the United 

 States the beetles are often driven in the above manner into a windrow of hay or 

 straw which is immediately set on fire, and thousands of the insects 'are thus de- 

 stroyed. 



In gardens many of these beetles may be killed by beating them from the 

 plants into pans containing water with a little coal oil on the surface. If any 

 of the species which feed on the blossoms of fruit or other trees should occur in 

 injurious numbers, many no doubt could be jarred from the trees into an inverted 

 umbrella, or other contrivance, and then put into a vessel containing coal oil and 

 water. 



On account of the good habits of the larvae of blister beetles in feeding 

 upon the eggs of grasshoppers, it is often undesirable to destroy them, but, of 

 course, when they occur in destructive numbers, it is well that one of the above 

 measures be taken as soon as possible for the protection of the crop. 



tThe Griddle mixture is made by mixing one pound of Paris green with five ordin- 

 ary pailfuls of horse droppings, which have been moistened with about half a pailful of 

 water in which two pounds of salt has been dissolved. It is simply scattered among 

 the crop which Is being attacked, or along the edge of a crop towards which the young 

 grasshoppers are working. 



