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oval, white, and opaqut-, and quite tough -- to those parts oi 

 the body not easily reached by the jaws and legs of their 

 victim and thus prevent the egg from being detached. The 

 slow-flying locusts are attacked while flying, and it is quite 

 amusing to watch the frantic efforts which one of them haunt- 

 ed by a Tachina-fly, will make to evade its enemy. The fly 

 buzzes around, awaiting her opportunity, and when the locust 

 jumps or flies, darts at it and attempts to attach her egg under 

 the wing or on the neck. The attempt frequently fails, but she 

 perseveres until she usualh' accomplishes her object. With 

 those locusts which fly readily, she has even greater difficulty; 

 but, though the locust tacks suddenly in all directions in 

 its efforts to avoid her, she circles close round it and gener- 

 ally accomplishes her purpose, either while the locust is 

 yet on the wing, or, more often, just as it alights from a flight 

 or hop. Tlie young maggots hatching from these eggs eat into 

 the bodv of the locust, and after rioting on the fatty parts of 

 the bod}' — leaving the more vital parts untouched — the}' 

 issue and burrow in the ground, where they contract to egg- 

 like puparia, from which the fly issues either the same season 

 or not till the following spring. A locust infested with this 

 parasite is more languid than it otherwise would be; yet it 

 seldom dies till the maggots have left ". (Jften in pulling off 

 the head or wings of a locust from which the maggots have 

 escaped, its body will have the appearance of a mere shell. So 

 efficient are these parasites that quite frequently the ground in 

 locust-infested regions is covered with dead and dying locusts. 



"In warm weather, these flies multiply very rapidly, under- 

 going all their transformations in the course of a fortnight 

 from leaving the egg; but in the cooler seasons the pupal de- 

 velopment under the ground is much slower, and the winter 

 is generally passed in the puparium, though we have known 

 the larvic to remain in the ground unchanged all through the 

 winter ''. 



Since all of these flies are less hardy than most migratory 

 locusts, and, as a rule, require a moister climate in which to 

 live, they only occasionally succeed in checking the pest upon 

 which they live. If the locusts could be placed in a humid lo- 

 cality and kept from migrating for several years these Ta- 

 china flies would end the plague. In some parts of North 

 America even these flies possess a migratory habit, large 

 swarms of them having frequently been observed following 

 locust-swarms. 



