August, ’20] 
HERBERT: WESTERN TWIG PRUNERS 
363 
monterey ( Cupressus macrocarpa) , arizona (C. arizonica), guadalupe 
(C. guadalupensis) , macnab (C. macnabiana), funeral (C. funebris), 
italian (C. sempervirens) , lawson (Chamaecyparts lawsoniana), hinoki 
(Ch. obtusa), and arbor vitae ( Thuya orientalis ), giant arbor vitae 
(Thuya plicata), and incense cedar ( Libocedrus decurrens). 
The beetles may be best controlled by burning up the infested txees, 
posts or poles in which they are breeding, or by removing the bark when 
they are in the younger stages, killing them by exposure. This will 
reduce the numbers liable to enter the twigs. 
The injured twigs may be trimmed from the trees, making them more 
presentable. Poison or repellent sprays have never been used, but 
may be of value in preventing the twig injury. 
Three specimens of a scolytid bark-beetle were discovered by the 
writer in broken twigs of ash ( Fraxinus spp.) on the Stanford Univer¬ 
sity campus in May, 1919. Many other twigs were broken down and 
wilted, showing the results of their work. Later, upon a closer exam¬ 
ination of the ash trees in this locality, a great many of the twigs were 
discovered to have been entered, while only a small percentage had 
been broken down. The entrances were found mostly at a bud or the 
axil of a twig, with the burrows spiralling down the twig under the 
bark for a quarter inch or more. 
The old brood galleries of these beetles were found in the dead tops 
of three nearby ash trees which had been killed apparently by this 
species. The parent galleries were under the bark, extending trans¬ 
verse to the limb, while the larvae which hatched from the eggs laid in 
niches on the sides of the galleries, mined parallel to the grain of the 
wood. All the limbs had been abandoned, but a dead beetle was found 
in a pupal cell, which proved to be identical with those in the twigs. 
Upon forwarding a specimen of the beetle to Dr. Hopkins at Wash¬ 
ington, D. C., he pronounced it as apparently an undescribed species 
of Leperisinus near aculeatus Say. He also stated that an allied 
species, L.fraxini, had been reported to be injurious to twigs in Europe, 
but that he believed no such injury had been reported in America. 
Among other twig pruners may be mentioned Agrilus angelicus 
Horn, the flat-headed oak twig girdler, the larva of which in making 
its spiral mines under the bark of various oak twigs, which it kills, 
occasionally goes deep enough into the wood to so weaken the branch 
that it is broken off by the wind. Two unidentified cerambycid 
larvae also work upon larger twigs of oak and sometimes cause the same 
injury. No work resembling that of the eastern hickory girdler, 
(Oncideres cingulata Say), has been observed in the West. 
(.Proceedings to be continued in the next issue) 
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