38 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



I. What is the result of your experience or observations as to the efficacy of Paris 

 green, or other arsenical compounds mixed with flour or plaster, for the destruction of 

 the cotton-caterpillar ? 



II. In what proportions, and in what mode, time, and frequency of application have 

 experiments been made ? 



III. Have any injurious effects of the poison been observed, either upon the plants 

 or the soil, or in human poisoning in its application, or in the destruction of beneficial 

 insects, as bees, ifec. ? 



IV. Have you used any other remedies, or means of extirpation, such as fires or 

 torches in the fields to destroy the perfect moths on their first appearance, and with 

 what success? 



Yours, respectfully, 



FRED'K WATTS, 

 ' Commissioner. 



The answers to this circular, published in the Department report for 

 1873, showed that the green was tried during the season in seven States 

 and seventy counties, and that its success had been almost uniform. 



The same year several patents were taken out for poisonous mixtures 

 to be used in destroying the Cotton Worm, and some of them reached 

 a great sale for a few years — notably Preston & Eobeira's " Texas Cot- 

 ton Worm Destroyer,'^ and Johnson's '^Dead Shot." But it has become 

 generally understood that the same ingredients can be used in slightly 

 differing proportions without infringing upon the patents, so that at the 

 present day the patents are generally disregarded. 



In the Monthly Eeport of the Department for I^ovember and Decem- 

 ber, 1872, Mr. E. H. Derby, of Boston, remarking upon the fact that the 

 worm would not eat jute, suggested that a belt of that plant around a 

 cotton-field might keep the worm away. A year later, in the Monthly 

 Report for ll^Tovember and December, 1873, Mr. E. La Franc, president 

 of the Southern Ramie Planting Association, detailed experiments with 

 three fields, which seemed to prove the practicability of the use of jute 

 as a preventive. Subsequent experiments, however, have failed, and it 

 is probable that from this article of Mr. La Franc's have spread the 

 numerous reports of the efficacy of jute, which are to be found in the 

 back files of many Southern papers. 



Since 1873 most of the advance in remedies has been in the way of 

 invention or improvement of machinery for the distribution of the poi- 

 sonous mixture upon the plants. This machinery will be fully discussed 

 in the chapter on remedies. 



The cheap arsenical poison known as London Purple was first expe- 

 rimented upon as a Cotton Worm remedy by us during the season of 

 1878, and the favorable results which followed its use induced extensive 

 experiments the next year. 



It is hardly necessary to add that it has grown into great favor wher- 

 ever it has been obtained pure and has been judiciously used. 



The only remaining remedy of importance — Py ret brum — was first 

 publicly recommended by the writer for this purpose in first edition of 

 this work, our first experiments with it upon the worms having been 

 made during the summer of 1878. 



