ORTHOPTERA OF INDIANA. ' 145 



but not the mites, which can easily work their way toward the sur- 

 face. 



Other parasitic animals hesides these mites often attack the dif- 

 ferent 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 Gordius. 

 If the body of such grasshopper or cricket be cut open the interior 

 is often found to be almost tilled 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 locusts are 

 abundant, one of these flies may often be seen hovering over a large 

 specimen, awaiting a favorable opportunity to deposit one or more 

 of its eggs on the neck or beneath the wing. These eggs hatch into 

 larvfe 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 attack locusts, katydids 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. Wlien the maggots of either 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 generation of locusts. 



The egg clusters of locusts, crickets and other Orthoptera in the 

 ground are often attacked by the larval forms of bee flies and blister 

 beetles. The bee flies are of a blackish gray color, densely covered 

 with pale yellow hairs, and in June and July may often be seen 

 hovering above the ground, or feeding upon the honey of various 

 species of wild flowers. Their eggs are laid among or close to the 

 egg masses of the locust, and their larvse feed upon and destroy 

 myriads of the eggs of the locusts and crickets. 



