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FRUIT AND SHADE TREE INSECTS 
American plum borer on pecans controlled by paradichlorobenzene.— 
Cc, B. Nickels, in charge of pecan insect investigations, Brownwood, Tex., 
reports that "In the process of transforming native trees into improved 
varieties, the branches less than 4 inches in diameter are sawed off 
in the dormant season. The following season sprouts emerge from the 
trees and they are budded. The larva of Euzophera tunnels around the 
sprout near to the point of junction on to the tree. This results in 
weakened branches that are easily blown off by the wind. * * * ‘70 pecan 
trees (30 years old) were treated with a mixture consisting of 1 pound 
of paradichlorobenzene to 2 quarts of cottonseed oil. * * * applied with 
a paint brush on all areas which externally showed evidence of infesta— 
tion. All of the trees were wormed 7 to 14 days after the application 
*** All together 298 larvae were removed from the trees; 43 larvae were 
alive; 180 larvae were apparently killed by the insecticide; and 75 lar-— 
vae (molded) apparently died from causes other than the application of the 
PDB mixture. Our records indicate that 80.7 percent of 2235 normal lar- 
vae were killed as a result of the insecticidal treatment. We did not ob— 
serve any injury to the trees * * * The vitality of the trees ismauee 
low point for a period of 2 to 3 years after topping, but after that time 
the trees become more vigorous and are attacked by Euzophera semifuneralis 
Walk to only a slight extent. 
Bark beetles invade roots of Monterey pine.-—-H. E. Burke, of the_ 
shade tree insect investigations, Palo Alto, Calif., reports that "Prac— 
tically all of the roots of the Monterey pine pulled on the Stanford 
Campus in March had the inner bark riddled by the mines of the beetles 
or larvae of Dendroctonus valens Lec. Some roots showed evidence of in- 
festation 9 feet from the stump. Some of the roots were 1 foot in diam— 
eter 6 feet from the stump. All of these observations indicate that in 
the Monterey pine in the San Francisco Bay region a large part of the 
brood of this insect develops underground, therefore no control can be 
successful unless the stumps and roots are treated, and whenever an im— 
provement cutting is made in the planted groves the stumps and roots 
should be removed. Otherwise there is great danger of starting a beetle 
epidemic. In the past it has been the custom to pile the brush on 
the stumps and burn. This burned the bark off the stumps but did not 
touch the roots. Evidently the roots have been producing most of the 
beetles that have been reinfesting the groves." 
Freezing points of three fruit insects.—-E. H. Siegler and Francis 
Munger, Takoma Park, Md., have been determining the undercooling and 
freezing points of several fruit insects. Pupae of the grape berry moth 
(Polychrosis viteana Clemens) supplied by G. A. Runner, of the Sandusky, 
Ohio, laboratory, showed undercooling points ranging from -11.2° F. to 
-35.7° F., with freezing points ranging from 1.1° F. to 8.1° F. Messrs. 
Siegler and Munger also state, "that the codling moth (Carpocapsa pomo-— 
nella L.) is able to survive the winter in our fruit-growing districts 
is almost entirely owing to its quiescent state as the temperature drops 
