330 



FESTS OF ORCHARD AND SMALL FRUITS 



of the opening buds. The adult thrips, which causes this injury, is 



a small, winged insect with sucking mouth parts. It comes out from its 



winter hiding place in the ground at the time that growth first starts, 



and as soon as the bud 

 scales have parted, works 

 its way down into the 

 flower, puncturing the tis- 

 sues and sucking the juices. 

 Egg laying begins later, 

 and the immature thrips 

 feeds on the tender leaf tis- 

 sues for two or three weeks. 

 Then it drops to the ground, 

 penetrates the soil to a 

 depth of three or four 

 inches, and remains there 

 until the following spring. 

 Direct control is possible 

 by means of timely and 



thorough spraying with tobacco extract (the commercial preparation), 



to which has been added distillate oil emulsion so as to make a 2 per 



cent solution. The emulsion is prepared 



by dissolving 8 pounds of whale-oil soap 



in 3 gallons of boiling water, and adding 



5 gallons of distillate oil (28 degrees 



Baume), at once driving the mixture 



through a spray pump into a tank or 



barrel. One gallon of the emulsion to 24 



gallons of the tobacco water will give a 



2 per cent solution. The spraying must 



be done just as the buds begin to un- 

 fold, and may need to be repeated. 

 Deep plowing followed by thorough 



cultivation in the fall, to disturb and destroy the pupating larvae, is 



of value. 



Fig. 512. 



Expanding buds killed by the Pear 

 Thrips. Original. 



Fig. 513.— The Pear Thrips. 

 Enlarged to fifteen times nat- 

 ural size. Original. 



