210 



THE AMEEICAN ENTOMOLOGIST. 



as "Army-worms." The real Army-worm {Leu- 

 cania unipunctata, Haw.) feeds upon grasses 

 and cereals, and received its popular name from 

 its habit of marching from field to field in im- 

 mense armies. That this species may at once 

 be recognized and distinguished from the insects 

 presently to be described, we publish an account 

 of it, with illustrations, in another part of the 

 present number of our Journal, to which the 

 readei;, pu refer. 



fc tiie northwest corner of the State of New 

 York, the Tent-caterpillar of the forest {Clisio- 

 [FiR. 147.] cam2M sylvatica, Harr.) has also 

 been erroneously known by the 

 name of "Army-worm." Wc 

 briefly sketched the history of 

 this species on page 208 of our 

 last number, and reproduce 

 herewith the figure of the worm 

 (Fig. 147). Though it may some- 

 times be found crawling along 

 roads in great numbers, and we 

 recently saw a great many run- 

 ning along a railroad track in the 

 heat of the sun, yet this Tent- 

 caterpillar of the forest cannot 

 with propriety be called an 

 Army-worm, and our Eastern 

 friends had best drop the title 

 Vwtc aTi'iTVufous': ' a)j[i avoid confusion in the future. 

 Again, the Cotton-worm {Anofnis xylina, 

 Say), which we are now considering, is very 

 generally known by the name of the " Cotton 

 Army-worm," and often simply as "the Army- 

 worm," in the South. The term as applied to 

 this species is not altogether inappropriate, as 

 the worm frequently appears in immense 

 armies, and when moved by necessity will 

 travel over the ground in "solid phalanx;" and 

 so long as the word '-Cotton" is attached— its 

 ravages being strictly confined to this plant — 

 there is no danger of its being confounded with 

 the true Army-worm. The term has further- 

 more received the sanction of custom in the 

 Southern States, and of Mr. Glover in liis De- 

 partment Reports. But there is in the South a 

 fourth insect {Laphrygma frugiperda, Sm. & 

 Abb. ?) which is frequently known by this omin- 

 ous name; an insect Avliich also will attack 

 cotton, though it prefers grass and weeds. This 

 last species in its habits resembles the true 

 Army-worm of the Middle States, more closely 

 perhaps than does tlie Cotton Army-worm 

 under consideration, and Mr. Joseph B. Lyman, 

 in his recent work on "Cotton culture*" (p. 92), 



calls it the "Army-worm;" yet, to prevent con- 

 fusion, the cognomen should be discontinued, 

 and the term "Southern Grass-worm" (by 

 which term it is already very generally known) 

 should be strictly applied to this fourth species 

 of the so-called "Army-worms." 



The Cotton-worm was first scientifically de- 

 scribed by Mr. Thomas Say, in the year 1827. 

 In 1800, according to Dr. Capers,* it was first 

 noticed as a destroyer of cotton, and was like- 

 wise very destructive in 1804, 1825, and 1826. 

 Since the last date, as we learn from old volumes 

 of the American Farmer, of Baltimore, Md., and 

 from the Patent Oflice Reports, it has done more 

 or less damage to the crop almost annually, in 

 some part or other of the cotton-growing dis- 

 trict. As with tlie real grass-feeding Araiy- 

 worm of flie Middle States, it swarms in par- 

 ticular years to such an extent as to utterly ruin 

 the crop, while in other years it is scarcely 

 noticed. This fact has led many to infer that 

 there is a stated periodicity in its returns in 

 such immense numbers ; but the natural liistory 

 of the worm confutes such an idea, while the 

 records give no foundation for the inference. 

 The sudden increase or decrease of this, as of 

 other species of noxious insects, depends on 

 climatic, as well as on other equally potent in- 

 fluences. 



[Fig. 14S.] 



Colors— (a) ijule green; (b, c and (J) prrccn, black and 

 yellowish j (/) brown. 



The egg (Fig. 148 a) which produces the Cot- 

 ton-worm is round, flat, and of a translucent 

 pale greeii color, and wheii viewed under a lens 

 appears i-egularly ribbed. These eggs are de- 

 posited upon the under side of the leaves, and, 

 from their small size, are naturally diflScult of 

 detection . Each female moth deposits from 400 

 to 600, and according to the late Thos. Aifleck, 

 of Brcnham, Texas, they hatch two days after 

 being deposited, if the weather be moist and 

 warm. The worms (Fig. 148 b, J grown) at 



* Patent Omce Itep., ISo.'i, p. 74. 



