22 THE BBPOBT OF THE No. 36 



Two locust enemies came prominently in-to play during 1920, both egg 

 destroyers. They were species of blister beetle and the Locust bee-fly (Systcechus 

 vulgaris). There is no doubt that these insects have been of marked benefit, and 

 at present they are by far the most promising of all the locust enemies. The 

 locust bee-fly has been especially notable for its destruction of locust eggs, in 

 6ome restricted areas ninety per cent, of the eggs being destroyed by its larvae, 

 while there are very few districts that do not show its presence in numbers. In 

 the earlier locust infested parts of the province, the Bee-flies occurred in enormous 

 numbers and during July they might be seen resting on nearly every blossom. 



We found blister beetles nearly everywhere though the abundance of the 

 various species is naturally governed by the presence or absence of their food 

 plants. The two most important species during 1920 were Macrobasis unicolor 

 var. murina and Cantharis sphcericollis. The first is somewhat of a pest to all 

 members of the pea family as well as to potatoes, and is often known as the 



Black Potato beetle. The Cantharis, on the other hand, has for its native food plant 

 the prairie snowberry, Symplioro carpus occidentalis, but from this it has spread 



to species of cultivated honeysuckle which it sometimes defoliates. 



Apart from these more important species there are two others of lesser 

 value, namely Epicauta sericans and Cantharis nuttalli. The first of these feeds 

 chiefly upon species of Anemone, but haa been found 1 eating lambsquarters also. 

 The latter is usually found upon members of the pea family, and is locally known 

 as the Caragana beetle owing to its habit of feeding upon that shrub. 



There seems to be little doubt that the larva? of each of these species destroy 

 locust eggs as the increase of the beetles coincide with a similar increase of 

 locusts. We have also reared some kinds from the egg, while others have been 

 found among them. 



In comparing the destruction wrought by the principal enemies of locusts' 

 egg's, I was interested to find that the larvse of bee-flies were much more numerous 

 in the egg-sacs of Camnula than in those of M elan o plus, while blister beetle 

 larva?, on the other hand, showed a marked preference for the eggs of the latter 

 genus. 



One other ally was reared from locust eggs during the year. It is, I think, 

 that small hymenopterous insect described by Riley as Scelio luggeri. As a rule 

 every egg in a sac will he infested, each producing a single adult. It is interesting 

 to know that this insect takes a full year to reach maturity and that it emerges 

 at the time when the locusts are busily laying eggs. The parasite, therefore, finds 

 abundance of food available for the perpetuation of the species. I am unable to 

 state, at present, what part this little insect played in the locust egg destruction 

 of 1920. 



On reviewing the results to date, I think we have every reason for being 

 satisfied with the progress attained. The artificial methods of control were all 

 that we could possibly expect. I do not think the country has ever been threatened 

 with such serious losses by insects and yet escaped so lightly, and this, of course 

 applies equally to Saskatchewan and Alberta. We have also reason for believing 

 that the locu- : ; outbreak in Manitoba has reached its greatest magnitude and that 

 next year wil' begin to show a reduction in the hordes of 'hoppers which have 

 given us so much trouble to date. Such reductions, when they do come, usually 

 terminate the outbreaks quickly. But while the prospects are encouraging for 



