163 



evidence I have been able to obtain appears to be one of our most val- 

 uable aids in the war against this pest. This species, as also Calosoma 

 mlidum, Pasimachus elongatus, and Harpalus catiginosus, will be found 

 described in the previous part of this report. 



Nos. 7 and 8 have been heretofore described, and are themselves 

 obnoxious species, depredating upon the potato also. The testimony 

 in their behalf is not sufficient to warrant our showing any favor to 

 them, and my advice is not to trust them, but to destroy them 

 wherever and whenever found. 



The five other beetles, Nos. 9 to 13, are Lady-bugs, and are valuable 

 friends, and should be carefully preserved. 



Nos. 14 to 19 are true bugs, which attack and kill the potato 

 beetles by piercing them with their beaks and extracting their 

 juices. 



No. 20 (Promachus apivorus) is a large, predaceous, two-winged fly, 

 called the "Nebraska bee-killer," which attacks indiscriminately almost 

 every insect that comes in its way, and has been noticed attacking 

 and killing the potato beetle. 



No. 24 (Lydella doryphorx) is also a two-winged fly, closely resem- 

 bling in color and size the common house fly, having, however, a 

 bright, silver-white face by which it may readily be distinguished. 

 It deposits its eggs in the body of the larva, and is a true parasite. 



Remedies. — I shall not attempt to enumerate here the various arti- 

 ficial remedies which have been proposed and tried for the purpose of 

 destroying or driving off these troublesome insects, most of which are 

 entirely worthless. There are, in fact, but two reliable ones — hand- 

 picking and the use of Paris green. The former method may answer 

 very well where but a small patch is to be protected, but where the 

 area in cultivation is any-ways large the latter is really the only 

 practically remed}', and fortunately it will to a great extent accom- 

 plish the work if properly and vigorously applied. Two principal 

 methods of application have been adopted, one in powder, the other 

 in solution. 



When the Paris green is applied in powder Dr. Le Baron suggests 

 the following precautions, in order to prevent any injurious effects: 



1. Always dilute the poison with at least ten times its bulk of 

 flour. 



2. Apply it to the plants when wet with dew or rain. 



3. Never entrust its use to young or careless persons. 



4. Never use it near the house where young children resort. 



5. Apply it with a gauze bag or some other sifter attached to the 

 end of a pole. 



0. Let the operator always keep on the side from which the wind 

 is blowing. 



7. Do not apply it to the plant where it will come in contact with 

 the fruit. 



In applying it in powder there should always be from ten to twelve 

 parts of common flour to one part of Paris green. 



Recent experience appears to give decided preference to the appli- 

 cation in liquid solution, especially since improved methods of apply- 

 ing it in this form have been invented. 



This not only avoids the danger of inhaling the powder, but it has 

 the advantage of rendering it more certain that the application will 



