THE MONTHLY BULLETIN. 



113 



first three body segments being black. There are one or two genera- 

 tions a year, according to the season and locality. The over-wintering 

 larvge make minute burrows in the bark, located principally in the 

 crotches of the limbs. These burrows or wintering quarters have been 

 found as early as JMay 17th, in Ventura County, the larvje coming out 

 early in the spring to feed on the tender shoots and starting buds. On 

 becoming full grown, they pass the resting stage in the crevices in the 

 bark of the trees, and emerge about a week later. The adults then lay 

 eggs, and there is a new brood of worms soon after this. 



The use of commercial lime-sulphur, diluted 1 part to 10 parts of 

 water, when the blossoms are just opening, has given excellent results. 



The Pear Thrips. 



The pear and the prune suffer the most from the attacks of the pear 

 thrips. Other hosts are the plum, prune, cherry, grape, etc. 



The resting stage of this insect is passed in the ground, the adults 

 emerging early in the spring, to deposit their whitish, bean-shaped eggs 

 in the tender tissues of the host plant. The adults and young attack 

 the flowers and the leaf buds. Tn badly infested orchards the buds 

 fail to open, and the trees appear brown and dead. 



Fig. 22. — Thrips' injury to the buds of Bart- 

 lett pear. (Courtesy U. S. Dept. Agr. ) 



About the time the thrips appear on the trees in the buds. Jones and 

 Foster^ recommend thorough spraying, using high pressure, holding 

 the nozzle close to the buds and directing this spray into the ends of 

 the buds. The Government formula consists of 3 per cent distillate 

 oil emulsion, combined with "Black Leaf 40," 1 part to 2,000 parts of 

 water. 



