52 



to the green. Amongst the first things that I heard of was that the whole locality 

 was overrun by the army worm, that they had eaten up every green thing and 

 were now devouring the Canada thistles for want of something better, and what- 

 ever was to become of the crops next year they did not know. On the first 

 opportunity I made personal observation — sure enough the thistles gave ample 

 evidence that they had been greviously ill-used, many of them with every leaf 

 gone and nothing but the bare stem left, and caterpillars everywhere. In one 

 locality where the road allowance ran between two farms with snake fences on 

 each side, there was, on the one hand, an old pasture field, very brown and deso- 

 late to look at, on the other was a summer fallow, which had in places a luxuriant 

 growth of Canada thistles, and I saw the worms crossing the road, in single and 

 double file, in colums and squares, platoons, companies and battalions of them, and 

 a toilsome march the}^ had of it, especially when crossing the road-bed, which 

 was deep with hot dust, leaving the dried up pasture field and all making direct 

 for the fallow, apparently with a full knowledge of the fact that there was food 

 to be got when they reached it ; and I observed that the thistles in the fallow 

 were being visibly reduced day by day. But it turned out that this all devour- 

 ing host which had been causing such consternation in that locality, was composed 

 entirely of the larvae of Pyrameis cardui, or the thistle butterfly ; and no doubt 

 but they had rigidly confined themselves all the time to their own natural and 

 proper diet. In due time they disappeared and nothing was heard of them 

 afterwards. 



The following is Mr. Ashmead's account of the outbreak of the army worm 

 above referred to : 



In accordance with Professor Eiley's instructions, on May 31, accompanied 

 by Mr. Albert I. Hayward, of the Maryland Agricultural College, I started for 

 Salisbury, Wicomico County, and Princess Anne, Somerset County. Md., to make 

 such observations on the army worm (Leucania unipuncta), then depredating in 

 the vicinity of these places, as the limited time at our disposal should permit. 



During our journey we ascertained, in conversation, that the worms were 

 most numerous in the immediate vicinity of Princess Anne, and we took the most 

 direct route for that place. 



As we approached our destination we began to see the efiects of the worms' 

 work ; just before entering the town we passed by a large field of corn, owned 

 by Mr. H. H. Deshields, containing about twelve acres, that had been devastated 

 by them, and only a few green plants could be detected here and there in the 

 field. 



This field was in marked contrast with another corn-field adjacent, which 

 had been saved from attacks by ditching, as recommended in the third report of 

 the U. S. Entomological Commission. Another thing observed was that this field 

 was flanked behind with a wood that evidently prevented their ingress that way, 

 whereas the former was contiguous to grass and wheat fields, in which the worms 

 are said to originate. 



Just before entering the town we passed another ten-acre corn-field, owned 

 by Mr. John L. Lormer, that but a short time previously presented a most pro- 

 mising appearance, but which to-day is completely " cleaned out " by the worms. 

 It may be worthy of record, as the theory has been advanced that insects originate 

 in just such places, that in an adjoining field were three old hay-stacks. Contrary 

 to our expectations we found the reports of their numbers not at all exaggerated, 

 and the damage done is even worse than we anticipated — the wheat, corn, barley 

 and timothy of many of the farmers being totally ruined by them. 



