42 



London purple, — Of twenty-two bugs placed on a potted grass 

 plant, dusted, plant and all, with London purple and enclosed in 

 a netting bag, eighteen were dead and four alive at the end of 

 seventeen hours. 



September 10. In a similar experiment on twenty-four bugs, 

 but six were found dead in sixteen hours. 



Paris green. — September 9. In a like experiment with chinch 

 bugs confined with growing grass and dusted thoroughly with 

 Paris green, but five were dead out of twenty at the end of forty 

 hours. In another, only three were found dead out of nineteen. 



Check lots of bugs not poisoned, showed at this time such a 

 susceptibility to confinement, owing probably to the existence of 

 disease among them, that little value can be attached to these 

 results. It is clear, at best, that only the arsenic can in any case 

 be worth considering. 



Egyptian insecticide. — This substance, received from the manu- 

 facturers,* was applied very freely to corn in the field, at Albion, 

 Illinois, August 21, 1888, being sprinkled thoroughly on stalks 

 and leaves, and behind the leaf sheaths. Nine and a half hours 

 afterwards the bugs were feeding as before, apparently not affected; 

 but a very heavy rain following, which washed the insecticide 

 down behind the leaves, the bugs on this corn seemed to be 

 diminished in number at the end of forty-eight hours. • In seventy- 

 two hours a few were found dead, but those living were as active 

 as before. The corn rows treated were, however, clearly less 

 abundantly infested after the rain than those adjacent. 



On the other hand, the dry powder applied very freely to six 

 bugs confined with a grass plant had not taken visible effect in 

 twenty-eight hours. 



Buhach. — In a single experiment with this powder applied dry 

 in the usual manner, all the bugs died within twenty-five hours. 



Corrosive sublimate. — An aqueous solution made with two grains 

 •of corrosive sublimate to six ounces of water, had no effect on 

 chinch bugs in two experiments, sixteen and twenty-four hours 

 after thorough application. 



Steam. — At the St. Clair county fair, in Belleville, September 

 11, 1888, Mr. George C. Bunsen, of that town, reported in the course 

 of remarks on the chinch bug, the successful use of steam thrown 

 against the stalks of corn from an apparatus of his invention. 

 Experiments subsequently made at the office showed that with 

 sufficient care steam may be used t(^ kill chinch bugs without in- 

 jury to the plants on wliicli they are exposed; but as the differ- 

 ence is slight between the time needed to kill or disable the 

 insects and that sufficing to (lainag(5 vegetable tissues (very slight 

 if the vegetation is at all fresh), the care required will usually be 

 such as to make the method impracticable in field operations. It 



'Egyptian Insecticide Co., 208 Pine Street, St. Loiila. 



