New York AGRICULTURAL EXPERIMENT STATION. 329 
viously stated the beetles feed voraciously on the new growth, pre- 
ferring the tender bark, but also feeding upon the leaves, and 
frequently devouring the young shoots before they have fairly 
started. 
The egg.— Egg-laying begins about the 10th to the 15th of May 
and may continue for a week or more. The eggs are deposited 
in groups, usually on the under surface of the willow leaves, but 
they were frequently found upon blades of grass or leaves of 
weeds growing in the willow rows. Each egg is firmly fastened 
on end to the leaf and usually in a slightly slanting position as 
shown at Plate XX, on the left of Figure 1. These groups vary 
in the number of eggs contained. In about 15 examined the num- 
ber varied from 25 to 52. The average number is about 45. 
The eggs are light lemon-yellow in color, turning to a deep 
salmon just before hatching. They are elongate-oval in outline 
and vary in size from 1.35 mm. by 0.63 mm. to 1.47 mm. by 0.84 
mm. ‘The shell is smooth, thick and leathery. 
Period of incubation.— The period of incubation is usually 
from 10 days to 2 weeks. This was the period for 1894, 1895 
and 1896. Last spring was an exception, as few of the eggs 
hatched within 20 days. 
The larva.— When first hatched the larvee measure from 1.05 
mm, to 1.11 mm. in length. The diameter of the head is 0.6 mm. 
and that of the body 0.54 mm. on the anterior half, tapering to 
0.21 mm. at the last abdominal segment. The entire body is black 
or very dark brown. When full grown they measure, on an 
average, about 8 mm. in length. The width of the head is 0.75 
mm. and of the body, on the anterior half, 2.5 mm. tapering to 
about 0.6 mm. on the last abdominal segment. The body is of a 
dirty yellowish color, the head a dark brown and the legs black. 
A double row of dark brown spots, two on each segment, extends 
along the upper surface of the abdomen. In a line with these is 
a row of black tubercles on each side which, when the insect is 
disturbed, emit drops of white milky fluid, of a strong pungent 
odor, which may be drawn back when the threatened danger is 
