28 ORTHOPTERA OF NORTHEASTERN AMERICA. 



other remedies against locusts is seen in regard to these red mites, 

 as the plowing of fields in which the eggs of locusts have been 

 deposited will destroy the young locusts hatching from them, but 

 not the mites, which can easily work their way toward the surface. 



Other parasitic animals besides these mites often attack the 

 different species of Orthoptera. On a number of occasions I have 

 found protruding from the abdomens of green grasshoppers and 

 crickets a slender "hair worm" or "horse-hair snake," a species of 

 Gorditis. If the body of such grasshopper or cricket be cut open 

 the interior is often found to be almost filled with this parasite, 

 which is many times longer than its host, and it will be seen that 

 all the important organs of the latter are pressed to one side and 

 unable to perform their necessary functions. Locusts so affected 

 are seldom able to propagate their kind. 



Among insect enemies of the Orthoptera, which aid largely in 

 keeping down their numbers, are "Tachina Flies," "Flesh Flies," 

 "Bee Flies," and "Blister Beetles." Tachina flies are mostly of a 

 gray color, and resemble large house flies. In fields where lo- 

 custs are abundant, one of these flies may often be seen hovering 

 over a large specimen, awaiting a favorable opportunity to de- 

 posit one or more of its eggs on the neck or beneath the wing. 

 These eggs hatch into larvre or maggots which eat their way into 

 the body of the locust. There they seem to avoid the most vital 

 parts, but feed upon the fatty secretions stored up for future use 

 of the reproductive organs. Locusts so affected have a soft, 

 flabby body, and can often be readily caught by the hand. They 

 never mate, and perish much sooner than the healthy, unaffected 

 individuals. 



The flesh flies of the genus Sarcophaga attack locusts, katy- 

 dids and grasshoppers in much the same manner as do the tachina 

 flies, and their maggots are often found existing as true parasites 

 upon the vitals of these Orthopterous insects. When the mag- 

 gots of these flies become full grown, they burrow through the 

 body wall of the locust and drop to the ground, where they enter 

 the earth and pass through the pupal stage from which they 

 emerge as fully winged insects, ready for attack upon a new gen- 

 eration of locusts. Webster (1007) records the receiving from 

 Wyoming of a large number of dead specimen of Melanoplus dif- 

 ferentialis (Thos.) which had been doing much damage to alfalfa. 

 When received the material was full of the maggots and pupa* of 

 Karcoplntcja gcorf/'mna Wied. 



