944 Popular Editions of Station Bulletins of the 



or spraying t o 

 destroy psylla eggs. 



The eggs about to hatch and the newly- 

 Spraying for eggs emerged nymphs succumb to an application oi 

 of winter flies . 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. 25.) Most growers 

 spray much earlier than this for the 

 San Jose scale, but by postponing 

 the treatment of pear orchards until 

 the blossom clusters are well advanced 

 one may deal another effective blow 

 against the psylla and with the same 

 treatment successfully combat the 

 scale. The lime-sulphur solution, v . OK r, . , 



testing 32°-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. 



A third opportunity to 

 Spraying for the strike hard at the psylla 

 first-brood is when all of the eggs 

 nymphs. have hatched and the young 



nymphs are largely assem- 

 bled in the axils of the young leaves and 

 fruits. This occurs normally during the 

 latter part of the blossoming period and 

 the young insects can be reached by spraying 

 just as the blossoms drop. The most satis- 

 factory spray i /is tobacco extract, using three- 

 fourths of a pint to one hundred gallons 

 of water to which are added from three to 

 five pounds of dissolved soap. (Formula 1.) 



The grower should endeavor 

 Late summer to combat the pest by the 

 spraying. preceding measures and thus 



avoid, if possible, the neces- 

 sity of later spraying. If the trees are badly infested during the 

 summer time it is a very difficult task to bring the pest under 



Fig. 24. — Too early for 

 most effective psylla 

 control. 



