REPORT OF THE STATE ENTOMOLOGIST I914 37 



such as red berries of the Tartarian honeysuckle. The eggs are 

 ordinarily deposited in thick tufts of grass, the oldest and toughest 

 stalks being selected and the eggs thrust down between the sheath and 

 the stalk and usually secured by a gummy secretion. There is an 

 evident preference on the part of the insect for cut straw in old stacks 

 and hayricks, etc. in the early part of the season. The frequent 

 occurrence of army worm outbreaks near rather low areas, especially 

 in the vicinity of thick growths of coarse plants, is undoubtedly due 

 to the moths searching out such conditions for the deposition of eggs. 



Habits of the caterpillars. The young caterpillars hatch from 

 the eggs in eight to ten days and remain in hiding most of the time, 

 feeding only during cloudy weather and at night. At first they eat 

 only the lower surface of the leaf and in about a week begin to gnaw 

 holes in the sides of the leaves. As growth continues there is a 

 marked increase in the feeding, and if the pests are at all numerous, 

 nearby provender is soon exhausted and the caterpillars are then 

 forced to move or march in the search of additional forage. This 

 extension of the feeding area may be scarcely noticeable or moderate 

 if the pests are not too abundant, or in the case of severe outbreaks, 

 especially if these occur in connection with the local scarcity of food, 

 may result in extended injuries, such as the destruction of acres of 

 grain, corn or even grass. The detection of an outbreak in one 

 locality is significant only as it indicates the probability of local con- 

 ditions being favorable for the abundance of the insect. There is no 

 danger of the caterpillars marching any great distance, five hundred 

 . to a thousand feet would probably represent the maximum, and this 

 would be reached only under exceptional conditions. 



Natural enemies. Army worms are subject to attack by a number 

 of natural enemies, especially the maggots of a grayish fly somewhat 

 resembling, though considerably larger than, the ordinary house fly. 

 The most important is known as the red-tailed Tachina fly, W i n t h e - 

 mia quadripustulata Fabr., a species which sometimes 

 occurs in swarms in badly infested fields and the one frequently 

 responsible for the almost total annihilation of a destructive genera- 

 tion. It is rare, if the second brood of army worms be abundant, to 

 have serious injury by the third generation, although the normal 

 prolificacy of the insect, if unchecked, would mean much more 

 extended damage. This beneficial fly and its allies deposit oval, 

 white eggs about one-twelfth of an inch long on the body of the 

 caterpillar, usually just behind the head, and wherever egg-bearing 

 army worms are numerous the chances of the succeeding brood 

 causing little damage are excellent. 

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