1920 EXTO.MOLOGlCAL SOCIETY. 4-j 



government official may be detailed to gather such data, so that Canada may reap 

 the advantages Avhich may flow from the application of the Law to agricultural 

 practice and to the solution of many entomological and other problems. 



FRIDAY MUILXIXU. !» OTLOCK. 



LOCUSTS IN MANITOBA. WITH SPECIAL KEFEHEXCE TO THE 



OUTBREAK OF 1919. 



Xor.MAN Ceiddle, Domixiox Entomolooical Laboeatoey, Teeesbaxk, Man. 



We have had locust plagues in the Prairie Provinces as far back as history 

 will take us ; that they occurred long before that time is extremely probable. There 

 were, however, no crops in those days and very few observers, consequently the 

 locust outbreaks were imperfectly recorded and our knowledge of the species involved 

 is extremely dubious. There were at least seven distinct locust outbreaks in the 

 Nineteenth Century most of which extended over two or more years. The iirst 

 was recorded from Lord Selkirk Red River colony in 1818, another probably 

 occurred about 1830; then we have records for: 1855-57, 1864-66. 1868-70, 18 <2- 

 75, 1897-98, and 1900 to 1904 of the new century. In other words there were 

 fully 22 locust years in the last hundred. Another significant point is that in 

 almost every instance the infestation lasted two or more years. 



Reading from Riley, and from Lugger of Minnesota, one notes that by far 

 the most important injury in all their records was attributed to the Migratory 

 locust, Melanoplus spreiis, a species which was supposed to have its permanent 

 abode in the foothills of the Rocky Mountains and from that breeding ground 

 to spread far over the surrounding country. In his later reports Liigger also 

 attributes much to the Lesser Migratory locust, J/, atlanis, andl^an a smaller extent 

 to the Pellucid locust. CamnuJa peUuc'ula. Judging from more recent occurrences 

 I think it Vould be safe in concluding tliat these latter species were present in 

 most of the former outbreaks, especially the Lesser Migratory locust whidi is, 

 after all, very like spreiis. 



It is evident from this brief summary of the past, that we can expect locusts 

 to become troublesome at intervals of about 15 years though these periodic visits 

 are not, of course, by any means regular. The insect's appearance depends largely 

 upon meteorological conditions among the most important of which are abnormally 

 dry seasons, especially during May and June. There is one other point to bear 

 in mind and that is while we talk of a locust outbreak every 15 years we should 

 remember that such an invasion does iiot necessarily cover the whole country 

 because, as a rule, it is far from doing so. Indeed most of our outbreaks have been 

 confined to the southern portion of the province. 



My personal experience with locusts dates back to 1900, when we had an 

 outbreak in our neighbourhood involving our own farm among the re-t. The 

 species concerned was chiefly atlanis though there were a fair numl)er of spreiis 

 among them for the first two years, after which that species disappeared and has 

 not, so far as I am aware, been heard of since. Much crop wa< destroyed the first 

 season owing to lack of knowledge and pr(»])er equipment. The second year, how- 

 ever, we learned the merits of poisoned baits and from that time forward the crni- 

 parativelv small losses were due almost entirely to neglect. 



