ANSWERS TO CIRCULAR NO. 7. [85] 



had made their appearance by destroying by hand, but without success ; for suddenly, 

 without the possibility of such an increase by reproduction, they would appear in such 

 numbers as to destroy every leaf in two or three days. Again, in another instance, 

 ■when no worms were in this neighborhood, four days after a diligent and careful 

 search, when no sign of them could be found, they suddenly appeared, and in three 

 days not a cotton leaf could be found in my field except about one acre near the mid- 

 dle of it, which was planted much later than the rest, not a leaf of which they touched, 

 although some of the branches interlocked ; but some weeks afterwards, when this 

 patch of cotton had arrived at the same stage of growth, it was also stripped of its 

 leaves as the other. In ail my observation, the worm when it has exhausted the sup- 

 ply of cotton lesif icill eat nothing eZse,but crawls up on the weeds, bushes, and fences^ 

 and dies. 



8. From this experience, connected with the facts of their irregular appearance, and 

 that only under the same conditions of wet, warm, and cloudy weather, which is always 

 unfavorable for a healthy growth of the cotton plant, and that ihe worm never ap- 

 pears in the spring or early summer, at least not in such numbers as to be noticed; 

 its power of quick reproduction ; its total absence from the cotton plant at that time 

 when it could not escape detection ; and the temperature of May aod June always 

 high enough for the development of the worm through all its forms, leads me to believe 

 that the Cotton Caterpillar is the spontaneous productiou of diseased cotton plants. 



9. All eflbrts to destroy and stop the progress of the worm when the condition for 

 its appearance and increase is favorable has proved futile so far as my experience 

 extends in the cultivation of cotton for thirty years. 



Yours, very respectfullv, 



H. 0. DIXON. - 

 Prof. C. y. Riley. 



Larissa, Cherokee County, Texas, 



Octoler 13, 1879. 

 In answer to your 4th inquiry, viz : ''Do wet or dry summers favor its multiplica- 

 tion?" I would answ-er that about ten years ago the' Rev. N. A. Davis, now of Jack- 

 sonville, in this county, suggested to me the probability that the small red or brown 

 ant, abundant in the South, was the natural enemy of the Cotton Worm, and especially 

 effective duriug dry summers. After two summers' observation, I was convinced of 

 the truth of the reverend gentleman's conclusions. His opinion and two years' obser- 

 vation induced me to write the following to one of our county papers: 



THE COTTOX WORM (1871). 



'•The danger from the Cotton Worm is now over and we may review the history of 

 its depredations during the summer. Only a few farmers have suffered save in the 

 anxiety which they have felt during the maturation of their crops. If you recollect, 

 the worm was worse duriug the few weeks following the rainy season ; and as the dry 

 season since advanced, the worm gradually receded and the hopes of the farmer 

 revived. The first generation of these troublesome insects appeared to have taken 

 place in the wettest lands early in the spring, and it was about the second generation 

 that menaced the crops. Wet weather favors the increase of the worm and dry 

 weather soon destroys it. This observation has been made by many farmers long ago. 

 A similar observation has long since been made in regard to the Cotton Louse. Early 

 in the spring (when the cotton is in its first and second leaf), if the weather is rainy, 

 the louse soon covers the tender cotton plant and threatens to destroy it. But when 

 the dry season supervenes the little insect disat)pears, and the plant soon recovers 

 from the mischief. To what shall we attribute the disappearance of the insect in both 

 cases ? It is evidently due to that little predatory and almost onmipotent ant which 

 retreats to its hole and gathers in large bunches in dry places during the rainy sea- 

 sons ; but whenever the drought sets in, it climbs the stalk of every plant in search of 

 |)rey. It is carnivorous and deals death and destruction among insects in the crawl- 

 ing stage of existence wherever it goes. When the Cotton Louse multiplies danger- 

 ously on the tender plant, favored by a rainy season, the farmer loses all hope of hit 

 crop, unless the dry weather comes and the little ant begins to milk the cows (the lice 

 are called 'ant cows') by climbing up to them and striking them with their hands, 

 and eating a fluid which is made to exude from them by the concussion. This proces* 

 Boon destroys them. Then, at a later season, especially if the ant is driven to its shel- 

 ter by rains, the Cotton Worm, having increased to a dangerous extent, threatens th« 

 more mature plant. Again the same ant, when the sunshine permits, saves the cotton 

 by climbing the stems and seizing the flouncing worm, cuts it into two on the ground, 

 CO which both have fallen in the struggle, and thus in a very short time it thinned out 

 the w-orm, either destroying or holding it in abeyance. 



•' The history of these two enemies of cotton-growers accords with the experience of 

 observers. The dry weather, ^er se, does not save the cotton from louse or worm in 



