29 
materially assist in the destruction of all noxious and destructive insect 
pests : 
Never plant watermelons two successive years in the same field. 
Plant always in an entirely new field and as far off as possible from 
ground in which they were grown the previous year. 
My reascn for recommending this is obvious on account of the pecul- 
iarity in the development and propagation of the Aphididae. The 
spring and summer broods in the majority of the species are vivipa- 
rous, while the fall brood of females are oviparous. The last, therefore, 
lay the eggs, which lie dormant in the ground all winter and hatch with 
the first warm breath of spring; now, then, if this field is plowed up 
and other crops planted, the young aphids have nothing to feed on 
and so perish. 
My observation on this species, too, has been, that it is only trouble- 
some in fields planted in melons two or three years in succession; new 
melon fields are not affected by it, or to such a small extent as to be un- 
noticeable. 
Spraying with a dilute emulsion of kerosene wil! doubtless prove an 
effectual remedy as with other plant-lice. The emulsion should be 
sprayed from the ground up so as toreach the under sides of the leaves, 
Professor Riley has figured and described devices for this method of 
spraying in his report as entomologist to the Department for 1883, pp. 
136-138, and Plates IV and V. 
REPORT ON BUFFALO-GNATS. 
By F. M. WessTER, Special Agent. 
LETTER OF TRANSMITTAL. 
LAFAYETTE, IND., April £0; 1886. 
Sir: I herewith transmit a report of my investigations of the habits of the Southern 
Buffalo-gnat. 
In accordance with your instructions I left my home in La Fayette, Indiana, on 
February 18, reaching Vicksburg, Mississippi, onthe20th. Learning here that these 
gnats appeared every season in greater or less numbers in the vicinity of Somerset 
Landivg, Tensas Parish, Louisiana, in company with Mr. T. C. Bedford, of Vicksburg, 
one of the leasers of Somerset Plantation, I left for that locality on the 22d, reach- 
ing our destination on the same day. 
On the 23d, the weather being very pieasant, the day was spent in riding about 
among the teams at work on the plantation, in the hopes of observing some of the 
earliest appearing gnats. 
During the afternoon swarms of aspeciesof Anthomyia were observed in the air, and 
I was informed that these were the insects that killed cattle and mules. The follow- 
ing day was both cold and rainy, and, in fact, during the two weeks following there 
were but two days of sunshine. 
During this inclement weather the lakes and bayous about Somerset were carefully 
exa'nined, no trace of the true gnat being fonnd. In the meantime larvee of An- 
thomyia were found in considerable abundance about decayed logs and among de- 
cayed leaves in the woods, and, as the planters to whom I applied for information ai- 
