COLOKADO POTATO-BEETLE. 7T 



live by suction. As these introduce their beak into the substance 

 of the plant, or its fruit, and imbibe the juices, they avoid the 

 poison which lies upon the surface. And as respects the former 

 class, the use of the Paris-green will have to be limited to those 

 insects which subsist upon low or herbaceous plants, as its appli- 

 cation to trees would evidently be inconvenient, expensive and 

 dangerous. There are at least three of oiir worst insect pests for 

 ■which the Paris green has been successfully used. These are the 

 Colorado Potato-bug, the several kinds of Blister-beetles [Lyttce), 

 which are sometimes almost equally destructive to the potato, and 

 the small, striped Cucumber-beetle {Diabrotica viitata), which, if 

 not properly counteracted, often repders the cultivation of cucum- 

 bers and melons an impossibility. One of the most satisfactory 

 reports that 1 have met with on this branch of the subject, is in a 

 paper read by Mr. Barler before the Alton Horticultural Society. 

 He applied the Paris-green mixed with four parts of flour, by 

 means of a sifter tied to the end of a long pole, to fifteen acres of 

 melon plants, "Absolutely every bug disappeared within twelve 

 hours after they were dusted." I have sought for opportunities 

 to submit this use of Paris-green to additional tests, the past sea- 

 son, but have not been able to find enough of these insects to serve 

 the purposes of experiment ; and Mr. Parker Earle informed me 

 that the same scarcity of them has been noticed in the southern 

 part of the State, and Mr. Galusha bore the same testimony re- 

 specting them in the more central section where he resides. This, 

 at first sight, would seem to be the more remarkable, as the 

 past hot and dry summer would have been favorable to their 

 multiplication ; but it is not improbable that the excessive rains of 

 the preceding year may have proved destructive to them at the 

 propagating season. 



The fear often expressed that the poisonous qualities of Paris- 

 green will be communicated to the potatoes, may be safely dis- 

 missed as unfounded. The article has been in use long enough to 

 have developed any such danger if it existed. 



Upon the whole the Paris-green, if properly used, may be con- 

 sidered to be an almost infallible remedy against the Colorado 

 Potato beetle, and many other leaf-eating insects. Any harm 

 from its use, either to the plants or the operator, can be obviated 

 by observing the following rules : 



