320 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



September 9, after sunset anotlier gallou of yeast in four gallons of water waa ap- 

 plied to cotton covered with young larvae and eggs, but with no result, so far as I 

 could see. 



It will be seen that the first of these experiments was tried during a rain, which 

 endured for some time, so that the yeast may have been washed from the leaves and 

 from the caterpillars before having an opportunity to act ; but if any of it adhered 

 the damp weather following was most favorable to" its development into the parasitic 

 form. The second was tried when the sun was shining early in the morning, ho that 

 it was exposed to sunlight for the greater part of one day, and could not have been 

 removed by rain till the following night. Like the former, this was subjected to 

 damp weather for a number of days. The third lot was applied in the early part of a 

 cloudy afternoon, and this was subjected to rains the next night and for several days. 

 The fourth lot was applied after sunset, and there was no rain on it for three days. 

 Moreover, these quantities of yeast were so applied as to wet eggs, larvae, and pupae 

 of Aletia. Other applications were made on a small scale at different times, but with 

 similar results. 



From these experiments it appears that under the most varied circumstances, many 

 of which are very favorable to the growth ot fungi, yeast in an active condition 

 failed to produce any fungoid disease on either the eggs, larvae, or ])ny}a.e o£ Aletia. 

 Furthermore, larvae contained in a tin box were drenched with yeast, being kept 

 thoroughly wet for over twenty-four hours, after which a part of the liqixid was 

 drained out, and the box remaining uncleaned, the larvae were kept and fed in it for 

 a week longer, at the end of which time they were still living and apparently suffer- 

 ing from no disease. This leads me to believe that though the PenicilUum or Aspergil- 

 lus developed from tomlae sometimes attack living animal tissues, they cannot be 

 utilized for the destruction of the cotton caterpillar. Yet, considering to Avhat an ex- 

 tent some insects suffer from fungoid diseases, it seems by uo means improijable that 

 some practical and economical method of parasiting noxious insects may some day be 

 discovered. 



Experiments were also conducted at the department upon insects in 

 my breeding-cages, but I was unable to see that any results were pro- 

 duced by the yeast. 



Modes of applying poisons. — Second in importance only to the choos- 

 ing of the most effectual poison is the adoption of the best mode of applying 

 the remedy. Although many methods have been adopted, they may be 

 classified under two general heads : First, use of poisons diluted with 

 water ; second, use of poisons diluted with some dry substance. 



Before entering upon the discussion of these methods, I wish to urge 

 the importance of making early preparations for poisoning. As yet most 

 planters do not seem to realize that fighting the worms is a part of the 

 necessary labor for raising a crop of cotton. As a rule no provision is 

 made for this work in the way of purchase of poison or implements for 

 its distribution, or conveniences for getting water, until the worms are 

 injuring the crop so badly that it is evident that something must be done 

 at once to save it. The result is that while the planter is engaged in 

 the preliminary work which should have been done months before, the 

 crop is destroyed. 



The following remark was made to me in almost the same words by 

 the majority of the planters with whom I talked u])on the subject: " The 

 trouble about poisoning is, a man may have a large field, the worms ap- 

 pear in it, and in three or four days the crop is destroyed before the 

 poison can be applied." Another expression which I often heard, and 

 which is equally suggestive of a lack of appreciation of the proper way 

 in which to contend against this insect, is the following : "The first and 

 second croi)S of worms do no harm ; it is not worth while to poison them ; 

 it is the third crop that does the injury." 



The cotton-worm will continue to be a scourge until all who raise cot- 

 ton, except perhaps those in the northern portions of the cotton belt, 

 incorporate in their estimate of the cost of producing a cro]3 the expense 

 of poisoning the worms. The fact that in almost every section there are 

 seasons during which the worms injure the cotton but little can almost 



