RErOET OF THE ENTOMOLOGIST. 



Ill 



A. — WET POISONS. 



August 7, iiiue barrels of water -n-ere applied, going over about three acios to tlxo 

 b;!iTeI. The tiuie si;eut was from 9 a. in. to sunset, and the first vain fell at about 

 niue o'clock the next morning. The substances used, their quantities, and the nutn- 

 bcr of dead worms just before the rain began are shown by the following table : 



I. — Wet poisons applied August 7, 1879. 



Rains occurred nearly every day for about a weelc after this was applied. On the 

 9th of August I found no dead worms, and examination with a lens showed very little 

 poison on the leaves ; nor was the cotton scorched except in one or two places where 

 the poison Avas a little thicker than usual ; but vines of the cow-pea growing in the 

 field were considerably injured. The caterpillars continuing to eat, we again poi- 

 soned this cotton on the 11th, 12th, and I3th of August. 



In the following table the quantity of poison per barrel of water is given, but in 

 some sections several barrels were used : 



* In all of my experiments where paste was used it was made by boiling wheat-flour in water, so as 

 to be a trifle thicker than the starch commonly ussd for stiffening linen articles. Some farmers, to 

 avoid the labor of boiling the paste, allow flour to ferment in water, obtaining a very good article in this 

 way. In either case it should be strained through muslin. Mr. Patrick Calahan, of Selma, merely stirs 

 two pounds of common starch in a bucketful of cold water, which is then added to 40 gallons of water 

 containing tho poison. 



When applying the poisons to sections 10 to 14, inclusive, we used two mules to 

 tlraw the distributing wagon, in which were the driver and two hands with i>ump8. 

 Another hand, with a two-mule wagon, was engaged in drawing water from a pond 

 to the ends of the cotton rows, where it was transferred to the other wagon. Owing 

 to the low specific gravity of London purple, the bulk of a pound of it is far greater 

 than that of an equal bulk of arsenic or Paris green, and the hands complainedthat it 

 pumped out harder than either of the other poisons named. Certain it is, that, other 

 conditions being about the same, a baricl went over three acres in section 11, while 

 in 13, 13, and 14 it went over only two. On section 10 tho pumps were worked less 

 rapidly, so that a barrel of water went over three acres. T%venty-four hours afrer each 

 section was poisoned I examined it to see what effect the poison had produced on the 

 wonns and cotton, and leaves plucked here and there v/ere examined with a lens to 

 discover how thoroughly the finely divided jjoison was applied. There was a consid- 

 able number of worms dead on section 10, and most of the others died before tho first 

 rainfall. The Pays green could be seen in very fine panicles in the minute liollows 

 everywhere on the surface of the leaf. The cotton plant was not in the least' injured. 

 On section 11 the percentage of dead worms after twenty- four hours was considerably 

 less than on 10, but before tho rain fell the greater part of the others were (bad. The 

 poison appeared as a line purple bloom on the surface of the leaf, and in a good many 



