450 Report of the Department of Entomology of the 



decreasing temperatures at this season on the movements of the 

 " flies " makes them especially vulnerable to spraying. In planning 

 for this work select days when there is no danger of the spraying 

 mixture freezing on the trees. The most satisfactory spray from the 

 standpoints of safety to fruit and leaf buds and effectiveness against 

 the insects is three-fourths of a pint of tobacco extract (40 per ct. 

 nicotine) to one hundred gallons of water to which are added 

 from three to five pounds of dissolved soap. (Formula 1). 



2. Spraying for eggs of winter "flies." — The eggs about to hatch 

 and the newly-emerged nymphs succumb to an application of the 

 lime-sulphur mixture. In this lies a 

 hint to the fruit-grower for an effective 

 use of this spray against the psylla as 

 well as the scale. The eggs of the 

 psylla are laid principally during April 

 and commence to hatch early in May 

 or when the blossom cluster-buds are 

 beginning to separate at the tips. 

 (Fig. 24.) Most growers spray much 

 earlier than this for the San Jose scale, 

 but by postponing the treatment of 

 pear orchards until the blossom clus- 

 ters are well advanced (Fig. 25) one Wffi&J 

 may deal an effective blow against the IlllP 

 psylla and with the same treatment 

 successfully combat the scale. The **»£££?££'£?"' 

 lime-sulphur solution, testing 32° to 



34° B., should be diluted in the proportion of one gallon to eight 

 or nine gallons of water. (Formula 4.) The spray should be used 

 in liberal quantities and pains should be exercised to wet all 

 portions of the tree, especially the fruit spurs and the under sides 

 of the young wood, where most of the eggs are laid. 



CLEAN CULTURE 



AND THE REMOVAL AND 

 BARK. 



DESTRUCTION OF ROUGH 



While the adult psyllas seem to prefer to spend the winter under 

 the loose bark of the trees, they may, nevertheless, seek shelter 

 under any waste which affords chances to hide. Matted weeds, 

 tufts of grass leaves, or rubbish on or about the trees present ideal 



