CONTROL OF CITRUS THRIPS IN CALIFORNIA AND ARIZONA. 13 
The spraying must be very thorough, and to be effective the insects 
must actually be hit by the spray. It will very much improve the 
results if the rodmen are shown the insect they are to spray for and 
just where it will be found in greatest numbers. In this way the object 
of spraying is made definite. By keeping the thrips reduced to a 
minimum during the period between the dropping of the petals and 
the time when the fruit is half grown, most of the fruit scarring and 
the leaf curl of the early summer growths of foliage can be prevented. 
An appheation at the proper time in late August or in September will 
prevent the severe leaf curling which usually occurs to all late summer 
growths. 
HOW TO SPRAY NURSERIES AND YOUNG TREES. 
For large nurseries, where the gas-engine outfit can be advan- 
tageously used, it is preferable to the hand outfit. Two 25-foot or 
even 15-foot leads of hose and 12-foot spray rods are generally most 
convenient for this work. However, when an outfit has already been 
fitted with 50-foot hose and 10-foot rods, with the intention of spray- 
ing older trees as well as nursery stock, this equipment may be made 
to serve very well for the latter. In such case the excess hose length 
should be coiled over a peg or bracket fastened to the spray tank or 
engine hood, so that the young trees will not be injured by the drag- 
ging hose. It is preferable in setting out a nursery to leave driveways 
wide enough to accommodate a sprayer and team at intervals through- 
out the length of the bed. Where it is desired to have the nursery 
rows 4 feet apart, which is the usual practice, it is convenient to have 
wagon room between the fourth and fifth rows from one side, and 
again between the 12th and 13th, 20th and 21st, etc. With this 
arrangement eight rows of trees, four either side of the driveway, 
may be reached each trip, using 12-foot spray rods; eight more rows 
may be taken on the return trip, ete. 
The large chamber-type or single Bordeaux nozzles may be used 
to good advantage, but the rapidity of delivery of the spray need not 
be so great as that necessary for orchard work. It is better to pro- 
gress more slowly, covering all portions of the little trees, without 
undue waste of liquid. The trees will need attention only when the 
growth is tender. 
