1911 ENTOMOLOGICAL SOCIETY. 61 



With regard to grasshoppers, it is strange that their regular periodic movements 

 have been hirgely overlooked, though no doubt this is partly due to a lack of know- 

 ledge as to where to look. At Aweme, Man., where locusts have been troublesome 

 of recent years, one instinctively looks up towards the sun, taking care to get behind 

 some building, or in some way hide the sun's disc and then, if there are any flying, 

 they will be easily observed within a radius of from one to fifteen diameters from the 

 sun. 



Wlien a locust has the instinctive incentive to fly, it is said to inflate the air 

 sacks along the side of its body; it then rises with a spiral movement, round and 

 round, higher and higher, until reaching a height of some hundred feet or more 

 and feeling the resistance of the wind it sails slowly away, usually flying with its 

 head facing the breeze if it is at all strong, and gradually) getting higher as it 

 moves along with it until it becomes a mere speck of glistening whitene.s, when 

 close in line with the sun and invisible elsewhere. When there is no breeze lit will 

 return obliquely to earth to await a more favorable opportunity. 



That this desire or instinct to fly elsewhere is no sudden impulse is shown by 

 the fact that a locust when disturbed seldom flies any great distance and in fact 

 seems incapable of doing so, wliile those that are prepared rise easily. Nor is the 

 movement due to lack of food as one often sees them rise in the midst of plenty. 

 No! it is Dame Nature's way of spreading her children over the country and she 

 has taught them through the law of natural selection to go and also how to pre- 

 pare for the journey. 



The migratory season commences soon after the locusts reach maturity, thait 

 is when they have passed their final moult, and some three or four weeks before 

 they commence laying eggs. It lasts almost a month. There is not, however, a 

 continual movement, only hot sunny days are chosen and even then the locust is 

 dependent on the wind which not only carries it along but indicates its direction 

 also. The days most preferred are days when the breeze averages some fifteen 

 miles an hour, though lesser winds as well as higher, are used to advantage ; locusts 

 seldom fly, however, when the wind is blowing hard. 



It is interesting to watch these .movements on a gusty day, wlien calm one 

 moment and breezy the next. Then every fresh gust is taken advantage of and 

 one sees hundreds of locusts rise on such occasions, as if having waited their oppor- 

 tunity. It is the same while looking up towards the sun, one moment will only 

 discover a few, the next a perfect swarm moving at different angles owing to the 

 breeze having slightly different directions at different heights, and so the journeys 

 continue first east, then west, south or north as the wind varies. At night they 

 apparently drop to earth * to infest new neighborhoods or perchance rise and move 

 elsewhere next day. But not all go. Among the Orthoptera especially, nature has 

 made a wise provision. Some are endowed with long wings; these are built es- 

 pecially for locomotion and conveying the insect long distances. Others of the 

 same species have short or rudimentary wings which obliges them to stay at home. 

 So that while the long-winged forms seek new homes, there are enough short-winged 

 l)rothcrs and sisters to carry on the family at home and incidentally the work of des- 

 truction also. 



•It is well known that some grasshoppers travel throughout the night. Such an 



instance is rplated by Prof. R. .T. TTnnter of Dissnsfeira longivevvis, and though I have 

 no direct evidence, it is possible that some of the Manitoba species are also nocturnal 

 during the migratory season. 



