118 
THE ELM TWIG-GIRDLER 
OBBRBA ULMICOLA CHITTENDEN. 
In October, 1901, Mr. E. S. G. Titus, an assistant in my office 
at the time, was told at Decatur, III, by Mr. Frank Torrence, in 
charge of the parks of that town, that the common white or Ameri- 
can ehn-trees* there had been injured during the last three or four 
years by an amputation of great numbers of small twigs in June. 
Tufts of three to five or six leaves, each borne by a twig which had 
been cut squarely ofif, as if by a knife, would fall so thickly that in 
places the ground was nearly covered by them under the larger 
trees. 
In consequence of a letter from Mr. E. A. Gastman, Superin- 
tendent of Schools at Decatur, written me May 10, 1902, reporting 
that this injury was just beginning for the season, Mr. Titus went 
to Decatur again on the 22d of May for a careful investigation of 
the subject. A considerable number of large elms in the city square 
(commonly called Central Park) were then being injured by some 
insect which was cutting off the young twigs, each bearing from 
two to seven fresh leaves. Other twigs, similarly injured but not 
yet detached, were found on a young elm-tree, beneath which were 
about twenty-five fallen leaf-clusters. 
Among the insects noticed at the time was a species of Oherca 
gnawing away the veins on the under side of the leaves. No eggs 
were found on or in the twigs at this visit, but three females and 
two males of this Oberea, taken from an elm, were placed May 23 
with twigs of that tree in a portable breeding-cage, carried about 
by Mr. Titus while he was traveling for the office. Two eggs found 
in a fresh elm t\\\g in this breeding-cage May 24, four more May 
28, and two May 29, together with a newly hatched larva found in 
one of these twigs May 30, made plain the cause of the injury. 
Later visits to Decatur by Mr. Titus, by Mr. F. M. Webster 
and by Mr. E. P. Taylor, together with breeding-cage observations 
and field and insectary experiments, have given me the materials 
for a fairly full account of this insect, especially interesting because 
of its power of injury to our most important shade tree, and also 
because it has lately been found infesting the cherry, and, in one 
case, the peach. 
^Ulinits americana. 
