THE ORTIIOPTHKA OF MINNESOTA. 41 



found in large numbers upon fences, etc., or they drag about 

 their enfeebled bodief5, separated from their relatives. When 

 these mites, fastened to locusts, become fully grown they drop 

 to the ground, and hide for several weeks without taking 

 anvfood. Gradually the pupal state is assumed, without 

 going through a molt, as would be the case if mites were 

 true insects. Inside this pupa, shown in Fig. 12, b, the 

 mature mite is formed. Breaking through the retaining 

 pupal skin it appears as an eight-legged being, which passes 

 the winter in the ground. But the mite is not idle, except 

 when the temperature sinks below the freezing point. It 

 feeds upon all sorts of soft food, and whenever it has access 

 to the eggs of locusts it greedily eats them. In soil contain- 

 ing eggs of locusts large numbers of these mites congregate. 

 They creep into ever}^ hole in search of these eggs and thrive 

 upon such rich food. The great advantage of plowing over 

 all other remedies is also seen in regard to these red-mites, as 

 the plowing of fields in which eggs of locusts have been de- 

 posited will destroy the young locusts hatching from them, 

 but not the mites, which can easilj' work their waj^ towards 

 the surface. Plowing destroys our enemies, but not our 

 friends! 



Tachina-Flies. — These beneficial flies are generally of a 

 ^ray color, and resemble very much large house-flies; they 

 are of very great assistance in killing locusts. In fields 

 crowded with locusts they can be seen buzzing around a 

 wide-awake hopper, who seems to know the threatening 

 danger, as he will dodge the flies in the most excited and 

 ridiculous manner. But all dodging and kicking proves in 

 most cases of no avail, as the persevering fl}^ will certainly 

 succeed in fastening its white and elongated egg upon the 

 neck of the victim or under its wings. The maggots hatch- 

 ing from such eggs eat their way into the body of the lo- 

 cust. Here they devour everything, frequentl}'- leaving, 

 however, the vital organs untouched, they being, ver\Mikely, 

 less tender than the fatty parts stored up for the formation 



