REPORT OF THE ENTOMOLOGIST. 187 



THE AEMY-WOEM. 



{Ueliopliila (Leucania) unipuncta Hav/ortli.) 

 Order Lepidoptera : family Noctuidae. 



Esitinp: the leaves aiuT heads of the different grasses and cereals, a wonn 1^ inches 

 long'. lonj^itndinally striped with black, yellow, and green, appearing in immense 

 numbers, and keeping together in a more or less compact *body when advancing 

 from one lield to another. 



Eeccnt inquiries from many sections of tlie country concerning tliis 

 celebrated pest have called to our attention tlie fact that, although it 

 has been thoroughly discussed by several State entomologists, the re- 

 ports of the Department of Agriculture have never contained more than 

 a mere passing notice of its injuries. Since the writings of the authors 

 referred to are accessible to but few farmers residing outside of the 

 States which published them, it seems advisable to introduce here a 

 review of the present knowledge concerning this insect.* 



As to the past history of the army- worm, it will suflSceto state briefly 

 that it has been known in this country since 1743 ; that it is impossible 

 to say whether it is an indigene or whether it has been introduced 

 from Europe ; that it is known in almost every part of the world j and 

 that its natural history first began to be studied in this country after 

 the great army-worm year of 1881. 



Tlie adult insect is a night-flying moth of a dull bro^vn. color, marked 

 in the center of each foreT\iug with a distinct white spot, and with an 

 expanse of wing of about 45"^™ (a little over an inch and three-quarters). 

 Fig. 2. 



The egg is white and almost spherical. Its average is .6°^" (.023 inch). 

 The perfect outhne is sometimes lost from the gummy substance which 

 covers it and which holds it in place. The moth deposits her eggs in 

 the folds of grass or grain, always concealing them from sight by push- 

 ing them down into the unfolded portion of the leaf, or by cementing 

 the edges of the leaf together over them. Sometimes, however, they 

 are laid in a partial fold and remain perfectly exposed to view. (PL I, 

 fig. 1.) The eggs are laid singly or in rows which sometimes contain as 

 many as fifteen or twenty. 



TJie larva, or worm, when full grown, is SS'^'"* (1^ inch) in length. 

 (PI. I, fig. 3.) During this stage— which lasts from fifteen to thirty 

 days — the worm casts its skin five times. Its body color is pale green, 

 clearly seen only on the ventral surface, varied elsewhere with longi- 

 tudinal stripes of yellow, gray, and black, the gray often so closely 

 dotted with black as to become dusky. The general arrangement of 

 the stripes is as follows : The entire back is occupied by a broad black 

 or dusky band, deepest at the middle and along each margin. On each 

 flank is a series of stripes, consisting of a median black or dusky band, 

 on each side of which is a greenish or yellow stripe of ecpial width, mar- 

 gined on either hand with dingy white that is set off by a mere line of 

 dark. Down the middle of the back is an interrupted narrow white 

 line, often clearly seen only near the head. 



* The best articles which have been written concerning its life history ai-e those of 

 Fitch (Sixth N. Y. Kept., p. 113), Riley (Kiglith Missonri Rept., p. 22), and Packard 

 (Report on the Rocky Mountain Locust and other Insects now injuring or likely to 

 injure Held and garden crops. From the Ninth Ann. Rept. U. S. Geol. &, Geog- Suxv. 

 of Terr.). ^ 



