U. S. DEPARTMENT OF AGRICULTURE. 
north attacks upon the fruit of the native butternut seem less exten- 
sive, although at least a few infested nuts can usually be found upon 
or beneath any bearing tree. A case of slight injury to the nuts was 
found in 1920 in Jefferson County, N. Y. At nearly the same time 
about 20 bearing butternut trees were examined along the St. Law- 
rence River, in St. Lawrence County, N. Y., and not a trace of the in- 
sect found. Beetles were reared from both shoots and fruit of •/. 
sieboldiana collected at Lockport, X. Y., and larvae were abundant in 
butternuts collected at Lake Winnepesaukee, in central New Hamp- 
shire. 
Occasionally the larvae are found boring in young shoots of butter- 
nut at French Creek, W. Va., oviposition evidently taking place in 
the tips of these shoots before the fruit is large enough to be attacked. 
On July 2, 1920, in the last-named locality, 60 half-grown butternuts 
were picked at random from the lower branches of one tree. Of these 
60 nuts 48 contained egg punctures of the curculio and 12 were 
sound. A number of nearly full-grown larvae were also found bor- 
ing in the terminal shoots and leaf petioles. These larvae averaged 
larger than those in the nuts, indicating, as in numerous other obser- 
vations made, that eggs are first laid in the shoots. 
LIFE HISTORY. 
The butternut curculio has but one generation annually, and, like 
other members of the genus, passes the winter in the adult stage. In 
West Virginia oviposition begins in May and continues practically 
all summer, apparently reaching its maximum the last of June or the 
first of July. 
EGG. 
The egg is oblong, oval, creamy white, with the surface like ground 
glass. (PI. I, D and E\ PL II, A i Z?, and C.) Three measured on 
July 2, 1920, were uniformly 1 mm. long by 0.6 mm. wide. Two 
measured on June 7, of the same year, were 0.9 mm. long by 0.6 mm. 
wide. Britton and Kirk 5 give the following dimensions : Length, 
0.95 mm. ; thickness, 0.57 mm. Most of the eggs hatch in from 8 to 
10 days, although the period may extend to 15 days. 
LARVA. 
The larvae are whitish, or dirty white, with brown head and black- 
ish mandibles. (PI. II, D- PI. Ill, A and B.) The length is 12 to 
13 mm. and the thickness 3 mm. Feeding in the nuts and shoots, they 
become full grown in four or five weeks and then enter the ground to 
pupate. Nuts that are attacked when very small usually furnish 
s Brixton, W. E., and Kirk, H. B. Op. cit. 
