144 



correct. We hope that you will keep us iuformed as to further developments. We 



regret that you have heeu unable to have the rafts removed. 



The crustacean which you call a shrimp is probably the freshwater prawn of the 



Mississippi River, Palcemon ohionis. I can not surmise the cause of its mortality. — 



[October 3, 1891.] 



The Horn-fly in Kentucky. ^ 



I wish to report the presence with us this season, for the first time in injurious 

 numbers, of the Horu-fly. All cattle feeders in my vicinity have noticed the unusual 

 numbers of small flies on their cattle during the summer and our attention was more 

 particularly directed to them when our cattle on delivery weighed from 100 to 150 

 pounds less per head than they should. In fact, in three mouths' grazing our cattle 

 have not gained over 50 pounds per head, whereas they should have gained that 

 much each month. In your 1889 report you do not seem to speak very favorably of 

 kerosene emulsion. Why is this? Do you doubt its effects being sufficiently lasting 

 or would you anticipate any ill effects upon the animals from its use? If it would 

 answer the purpose I think it could be more readily applied from a knapsack sprayer 

 than other preparations, and then, too, the ingredients could be readily obtained by 

 every handler of cattle. I still have some cattle and the flies are as bad as ever. — 

 [P. T. Henshaw, Oldham County, Ky., August 20, 1891. 



Reply. — You are mistaken in supposing that I do not believe that the kerosene 



emulsion will be a good substance to apply to cattle. I am quite of the opinion that 



where they can be treated by means of a knai)sack sprayer with this substance^ 



about twice a week, the flies will be kept from the cattle and the resulting loss of 



flesh and diminution iu milk will be to a large extent avoided. * * * — [August 



24, 1891.] 



Non-migratory Locust Devastations in Nevada. 



I take the liberty of sending specimens of the grasshoppers which have been very 

 destructive over a certain region of desert country where the few fertile margins of 

 streams are cultivated for grain, hay, and fruit. Grain growing during the winter 

 months and ripening early in May escapes the hoppers, who do not hatch out till 

 May. They then destroy the summer crops, consisting chiefly of alfalfa (here called 

 lucerne) and fruits — grapes, pomegranates, figs, pears, and almonds, being the chief 

 fruits. 



It would long ago have been a region of importance for exporting these fruits if 

 the hoppers had not devastated it continually for a long term of years. I send these 

 specimens and this description in the hope that your entomologist may be able to 

 suggest some practicable chemical means of destruction. Any substance that could 

 be conveyed on the irrigating streams so as to reach every portion of the crop, and 

 would not injure vegetation, such as the hydrocarbon compounds, might be made 

 the vehicle of conveying the destructive agent, if such can be found. Purely 

 mechanical means are scarcely practicable on a large field. I have tried the Cali- 

 fornia remedy of arsenic with flour and sugar in a paste, and can not say what it 

 would do if genuine. The 10 pounds of arsenic I tried did not kill any hoppers; I 

 think it was simply a swindle, the merchant sending flour and lime instead of arsenic. 

 These grasshoppers are everyway local and never migrate ; they will be many years 

 spreading over a few miles of country, as for instance, the neighboring valley of the 

 Muddy, the lowest settlement, has had them now 22 j^ears without intermission. 

 Some years thej' were not quite so thick, other years thick enough to eat off the 

 grapevines three times during the summer and the leaves off all the cottonwoods, so 

 that big trees would dry up. They ate the alfalfa clear to the ground, while the 

 other towns in the valley, from 7 to 30 miles off, had none of the hoppers, or so few 

 that they did no harm. This season they have spread over all the valley. I had a 

 vineyard of 10 acres — 10,000 vines — at St. Thomas. If the hoppers had been absent 

 it would have yielded annually 5,000 to 8,000 gallons of wine; as it was it has yielded 

 less than the amount of State taxes paid on the land, and I could only find tenants 

 by reason of a dwelling-house being on the place. 



