130 THE CANADIAN ENTOMOLOGIST. 



ENTOMOLOGY FOR BEGINNERS. 



MIGRATORY INSECTS. 



BY G. J. BOWLES, MONTREAL, P. Q. 



The migratory instinct, common to so many species of birds, and even 

 of mammalia, is also exhibited by many species of insects. In the case 

 of birds and animals it has mostly to do with variations of climate, or the 

 necessity of suitably providing for the raising of their young ; in the case 

 of insects the causes of migrations are not so evident, and observation is 

 required in order to decide the point, if, indeed, it can be decided at all. 

 The subject is still in obscurity, though the efforts of American Ento- 

 mologists have thrown a little light upon it with regard to some species. 

 And it is of great interest, not only to Entomologists, but also to tillers of 

 the soil, as some of the insects which exhibit this migratory instinct are 

 among the most injurious to the crops of the farmer and fruit grower. 



THE LOCUST. 



Chief among the migratory insects stands the locust, considered as a 

 group. On each of the continents, both of the old and new worlds, some 

 species of the locust tribe have from time to time been notorious for this 

 habit, not only on account of the countless numbers in which they have 

 appeared, but also on account of the terrible destruction they have 

 caused. As far back as the time of Moses their ravages are mentioned, 

 for one of the plagues brought upon Egypt just before the departure of 

 the children of Israel was the plague of locusts. In Asia, Africa and 

 Europe their iavasions have been recorded in history, both ancient and 

 modern. To show the magnitude of the effects consequent on their 

 migrations, I give a few instances, as taken by Dr. Packard from different 

 historical sources. The first account, after Joel in the Bible, whose 

 descriptions apply to Egypt, Syria, Palestine and Asia Minor, is the state- 

 ment of Orosius that in the year of the world 3800 certain regions of 

 North Africa were visited by monstrous swarms ; the wind blew them into 

 the sea, and the bodies washed ashore " stank more than the corpses of a 

 hundred thousand men." Another locust plague, resulting in a famine 

 and contagious disorders, according to St. Augustine, occurred in the 

 Kingdom of Masinissa, and caused the death of about 800,000 persons. 

 Pliny states that the locusts visited Italy, flying from Africa. In Europe 



