FLOUR PASTE AS A COXTROL FOR RED SPIDERS. 3 



Two hopvines were accordingly sprayed, one with lime-sulphur 

 straight and the other with lime-sulphur and flour paste, 4-100. 

 The relative spreading effect of these two sprays is shown in fig- 

 ure 1. The left half of the figure represents the lime-sulphur and 

 the flour paste in combination, while the right half represents the 

 lime-sulphur straight. The .spotted effect produced by the lime- 

 sulphur mixture alone is in strong contrast to the even appearance 

 of the other half of the illustration. 



During some spraying experiments with nicotine sulphate and 

 flour paste upon the hop aphis it was observed that many of the 

 smaller aphides had become pasted onto the leaves. From this data 

 it was assumed that a stronger solution of paste would be effective 

 against the more delicate aphides and mites, and the following 

 experiments were conducted upon the red spider. 



Table III. — Results of experiments irith flour paste sprayed against the red 

 spider on hops in the Saeramento Valley of California, 1912. 



The.se experiments prove that flour paste, 8-100 and 10-100. is 

 effective against Tetranychus Vimaculatus. The paste has no effect 

 upon the eggs, however, and in controlling the mites a second 

 application T to 10 days after the first is necessary to catch the mites 

 that emerge from the eggs.^ 



A few preliminary experiments were conducted with this material 

 upon TetranycJiKs myt'daspkUs Riley which was attacking pears, with 

 very encouraging results, and it is very probable that flour paste, 

 8-100. will give good results when applied for any of the small leaf- 

 feeding mites. 



The last of June, 1912, flour paste. 8-100, was applied for the hop 

 aphis (then in the younger stages) with a 97 per cent efficiency. 

 These were encouraging results, but later experiments proved that. 



^ In moderate weather allow 10 days and in hot weather 7 days between 

 applications. 



