[84] REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



inflammation and inflammation of the neighboring lymphatic glands; no case, how- 

 ever, to my knowledge, has ever been known to result seriously. Third, as to animals : 

 I know nothing of any serious accident to them. 



15. The best method yet tried is the application of the Paris green suspended in 

 water, 1 pound to 40 gallons. The Paris green being the arsenite of copper, it is not 

 soluble in water, and when the two are mixed the Paris green is only suspended ; 

 hence it is necessary to keep the mixture constantly agitated, otherwise some portions 

 will be stronger than others, and will in that case be apt to injure the plant. 



The mode of applying it differs according to the means of the planter using the poi- 

 son. Many persons make brooms of the Mayweed (Anthemis cotula), which are handy 

 and very convenient ; others use the common garden watering-pot with the perforated 

 nozzle, Avhich is expeditious, efficacious, and at the same time inexpensive. The best 

 mode yet found is with the fountain-pump; with this the work can be accomplished 

 with neatness and dispatch without wetting the clothes of the one applying it. The 

 poison must be applied just after the worms are hatched and begin to crawl, other- 

 wise it will be too late. It requires careful looking to find the worms at this stage of 

 their existence. Four or five days after the butterfly emerges from the chrysalides 

 she begins to lay her eggs, on the under side of the leaf, and after about the same time 

 the eggs begin to hatch; then look carefully under the leaf in the locality where you 

 expected to find them, and almost to a certainty they are there. In order to better 

 find them every planter should provide himself with a small magnifying glass, which 

 will cost him only about twenty-five cents. This summer I had in my office one leaf 

 from the cotton plant, and on it there were ten worms and in it at least one thousand 

 holes, yet on handing it to several persons they failed to see either caterpillars or holes 

 until they were pointed out to them. 



By request I received the following letter from one of our largest planters: 



Natchitoches, La., September 2Q, 1879. 



Dear Sir : In 1876 1 exi^erimented with arsenic to destroy caterpillars, with the fol- 

 lowing result: I took one pound of 16 ounces of commercial arsenic, which cost 

 about 25 cents per xjouud, dissolved it by boiling in 8 gallons of water : after it was 

 dissolved replaced the quantity of water lost by evaporation; with this 8 gallons I 

 went to work. 1st. Put 2 gallons of the solution in a pork-barrel of water, say 33 gal- 

 lons, sprinkled two rows of cotton ; result of this application was death to both cotton 

 and worms. 2d. I then used 1-^ gallons to the barrel of water; same result to the 

 worms, cotton badly scalded. 3d. I then took one gallon of the solution and put it in a 

 barrel of water ; this time my solution seemed to be a little too strong, but did no per- 

 ceptible injury to the plaut ; the leaves retained their color except iu places. A fourth 

 application of three-quarters of a gallon of the solution to a barrel of water was tried 

 and found of sufficient strength to kill the worms and not damage the i)lant. These 

 experiments were made at the same time Paris green was applied to the balance of 

 the cotton on the plantation, none, however, being used when the arsenic was ap- 

 plied. The rows in which the last two applications were made (i. e., 1 gallon and f 

 gallon to the barrel of water) the. cotton lived and bloomed about three weeks, at 

 which time the worms destroyed all of the cotton on the plantation. 

 Respectfullv, 



H. B. WALMSLEY. 



Dr. George E. Gillespie. 



The Paris green has been sold in this market for $1 per pound, but it can now be 

 bought for from 25 to 35 cents per pound. It is calculated that three-quarters of a 

 pound will poison an acre; however, if the application is made just before a rain, it 

 will be necessary to repeat it. Most planters think that |1 per acre will cover all the 

 necessary expenses. 

 Respectfullv, 



GEO. E. GILLESPIE, M. D. 

 C. V. Riley, Chief U. S. E. C. 



Jackson, Miss., Sepemler — , 1879. 

 In answer to some of the questions of your circular No. 7: 



4. Warm, wet, and cloudy weather favors the appearance and reproduction of the 

 Cotton Caterpillar. 



5. Never have known them to appear in the spring w^hen June and July have been 

 wet ; the 1st August is about the earliest period in this locality. 



6. In cotton of the largest growth without regard to the situation. 



7. Observation has led me to believe that the worm in none of its forms lives through 

 dur winters in this locality, and also form an opinion in direct variance with science 

 as taught in the schools. " I have attempted to arrest their increase when only a few 



