133 
elm treated, and the time required for the spraying varied simi- 
larly from about ten minutes to an hour. The force necessary was 
three men and a boy, the latter to keep the solution constantly 
stirred during the spraying. 
The most suitable time for the first spraying- is obviously that 
just preceding the appearance of the adult beetles on the leaves. 
May 23, vv'hen this experiment was begun, 5 per cent, of the insects 
in the twigs were still larvae, another 5 per cent, were pupa?, and 
90 per cent, w'ere adults about to emerge. It was estimated by Mr. 
Taylor that possibly 5 or 10 per cent, of the beetles had already 
come out of their burrows and were feeding on the leaves, although 
very few, if any, twigs had fallen as yet in consequence of the gird- 
ling operations of the female beetles. 
Description. 
(PJate VIII.) 
Adult. — Form slender. Head, antennae, and elytra black, with 
gray pubescence, becoming long and dense on the head, nearly ob- 
scuring the punctures, and darker plumbeous-gray on the thorax. 
Antenn;c slender, long, five sixths of the length of the entire insect. 
Head somewhat feebly and sparsely punctate, with strongly defined 
median line, especially in the posterior portion. Thorax yellow, cal- 
losities black, occasionally with a smaller black antescutellar spot on 
each side; just above the leg there is usually another variable black 
spot, either smaller or much larger than the others. Elytra with l^asal 
portion on each side of and including the scutellum, yellow, occa- 
sionally with a longitudinal yellow streak on each elytron, extending 
from the base nearly to the apex, which is emarginate and sub-bi- 
dentate; the surface comparatively sparsely and feebly punctate. 
Epipleurse yellow. Ventral surface usually yellow, but occasionally 
with a portion of the thorax and of the second and third abdominal 
segments and less frequently the first and last segments black. Punc- 
tuation very shallow, nearly obsolete on abdominal segments. Prox- 
imal portion of legs yellow, distal portion black. 
Length, 9-13 mm.; width, 1.2-2.0 mm. Average length, 
12 mm.; width, 1.9 mm. 
Bgg. — Length, 3 mm. ; width, 0.6 mm. ; slightly reniform, of 
a creamy white color, without perceivable reticulations. 
Larva. — Length, 14 mm. Head much smaller than thoracic 
seg'ments, body decreasing in width posteriorly with moderate uni- 
formity to the eighth segment, which is considerably smaller, the 
anal still more reduced; body light straw-color, the two posteri'~>r 
