16 THE EEPOET OF THE No. 36 



time, and of course before I heard from Knight, that he felt sure they had come 

 from the oak trees because a few days before they were very plentiful on these 

 trees. An inspection of the orchard also revealed that the farther the peach trees 

 were situated from the oaks the fewer the number of adults and of injuries. This 

 was true even of peaches alongside a pond surrounded by such trees as poplar, 

 sassafras, willow and sumac but not oaks. 



As fully three-quarters of the oak trees in the woods were not white oaks 

 but red oaks with sharp pointed lobes on the leaves, I cannot help but think that 

 Lygus quercalbae must breed on red oak also. Another thing that tends to confirm 

 this belief is that numerous eggs of a Mirid were found on red oak twigs, either 

 in the tissues beneath or alongside the newly formed buds or beneath the leaf 

 stem. Eggs on white oak were also easily found in the same place though more 

 in this case were situated beneath the leaf stem. This slight variation, however, 

 could be accounted for easily by the difference in size of the buds of the two 

 varieties. Knight tells me that Parrott reported to him from New York State a 

 similar case of injury to peaches this year from Lygus caryae, the adults having 

 flown into the orchard from hickory trees on which they breed. 



Whether the above action of Lygus quercalbae and L. caryae portends a greater 

 amount of trouble in orchards from Miridae or not. only time can tell, but I 

 sincerely hope it does not because they are among the most difficult of insects 

 to control. 



THE MANITOBA GRASSHOPPER CAMPAIGN OF 1920. 



A. V. Mitchener, Winnipeg, Man. 



As early as the year 1865 we have records of damage done by grasshoppers 

 in Manitoba. The Eocky Mountain Locust (Melanoplus spretus) migrated from 

 the south-west to the Eed Eiver Valley and entirely devoured the crops of those 

 early settlers. Since that time there have been outbreaks of locusts at various 

 times, but none so severe and extended as the outbreak which began in 1919. 

 During that year, damage was largely confined to a restricted portion of the 

 south-western part of Manitoba. In the spring of 1920, grasshoppers appeared 

 over a much larger area; and it is with this particular phase of the outbreak that 

 we are here concerned. 



The area most severely infested in 1920' included six municipalities in the 

 extreme south-western corner of the province with an area of 1,728 square miles. 

 Here practically every farm was polluted with eggs, and later on with locusts. 

 Outside of this area and immediately surrounding it on the north and on the 

 west was an area of over 4,000 square miles where the infestation was less severe 

 on an average but where grasshoppers were very numerous in places. In other 

 parts of the province there were scattered areas, usually not large, where grass- 

 hoppers did some damage to the crops. 



On May 17th when the area was first visited, young grasshoppers were hatching 

 in great numbers from the lighter soils. Examinations were made in the sod along 

 roadsides, fences, lanes, etc., and in stubble fields to find out what the prospects 

 were for grasshoppers later in the season. As many as seventy-five egg clusters 



