138 Bulletin 224. 



eight nozzle's, it is necessary to have a continuous pressure of from 

 SO to 100 pounds. All spray pumps should have a pressure gauge 

 attached. It is too laborious and expensive to maintain this pressure 

 by hand-power in large vineyards. But it can be done cheaply and 

 practicably by horse-power aided by compressed air, by compressed 

 air alone, by compressed carbonic-acid gas, and by steam or gas 

 engines. There are now various types of such power spraying 

 machines on the market, but they need further adapting and strength- 

 ening for vineyard work. Horse-power alone does not seem to work 

 up sufficient continuous pressure for six or eight nozzles. Perhaps the 

 cheapest and most available way of obtaining a satisfactory pressure 

 is by attaching to a horse-power machine an air-tank in which air is 

 being continuously compressed as the horses move. A strong and 

 durable machine, thus combining horse-power and compressed air, 

 which will supply a continuous pressure of 80 to 100 pounds to six 

 or eight fixed nozzles properly arranged would enable vineyardists to 

 effectively fight their insect and fungous enemies at a minimum of 

 expense for power. 



The apparatus for using compressed air, or steam, or gasoline 

 power is rather expensive, but with good pumps and properly arranged 

 nozzles, very effective and satisfactory work can be done cheaply 

 and quickly. The tanks of compressed carbonic-acid afford a neat, 

 compact and very efficient power; but they are somewhat expensive 

 and obtainable only in large cities. 



II. A NEW GRAPE ENEMY: THE GRAPE BLOSSOM-BUD 



GNAT. 



Family Cecidomyiidae. 



Vineyardists often find after blossoming time that there has been 

 a poor " setting of the fruit " on many of the grape clusters, and the 

 clusters present a ragged appearance throughout the season. Usually 

 this is attributed to unfavorable weather conditions, either frost or 

 rains, which kill the blossoms or prevent proper fertilization. Doubt- 

 less these causes are often responsible for the ragged clusters of fruit, 

 but we have discoA-ered another cause which sometimes may have 

 more to do with it than weather conditions. 



The discovery. — On June 12, 1904, when the blossom-buds of the 

 grape clusters were about two-thirds developed in a Westfield vine- 

 yard, the attention of the junior author was attracted by some of the 

 buds that were about twice as large as the normal ones, and of a 

 yellowish or dark reddish color, with a watery and swollen appearance. 



