CURCULIOS THAT ATTACK WALNUT AND HICKORY. 5 
enough food to bring only one larva to maturity, but nuts that become 
infested when larger may contain from four to six larvae which reach 
full growth. After leaving their feeding places preparatory to 
pupation the larvae are active and crawl rapidly. When exposed to 
the light they have a habit of bending and catching the anal tip under 
the jaws and then releasing the tip with a jerk, sometimes throwing 
themselves in this way a distance equal to the length of the body. The 
larvae issue chiefly in the early morning hours and enter the soil as 
quickly thereafter as possible. In West Virginia larvae began to 
issue from butternuts on July 18 and continued to appear until Sep- 
tember 4. Table 1 shows the rate of emergence. 
Table 1. — Time and rate of emergence of larvw of the butternut curculio from 
half a bushel of butternuts at French Creek, W. Va., during the season of 
1920. 
Date. 
Num- 
ber of 
larvae. 
Date. 
Num- 
ber of 
larvae. 
Date. 
Num- 
ber of 
larvae. 
July 18. 
3 

16 

9 
1 
5 
11 
153 
22 
10 
2 
1 

13 
97 
40 
1 
4 
2 
• 5 
1 
8 
4 
5 
2 
2 
7 
4 


4 
1 

1 
9 
Aug. 23 
9 
19. . 
6 
24 
25 
26 
3 
20 
7 
1 
21. 
8 .. 
9 
10 
1 
22... 
27 

23 
28 

24. . 
11 
12 ... 
13 
14 
29 

25... . 
30 

26 
31 

27 
Sept. 1 

28 
15 
2 
3 
29... 
16 
17. 
3 

30... 
4. . 
4 
31 
18 
19 
20 
5 

Total 
2 
464 
3 
21. . 
4 
22 
As set forth in Table 1, 464 larvae issued from half a bushel of in- 
fested butternuts over a period of 49 days. It is an interesting fact 
that emergence was much more rapid during cool than warm weather. 
For example, on the mornings of July 26 and August 2, the dates of 
maximum emergence of the larvae, the temperature registered, re- 
spectively, 46° and 54° F. More than half the entire number of 
larvae issued on these two mornings of unusual cold. 
PUPA. 
The pupa (PI. Ill, C) is creamy white, the color deepening and 
the eyes becoming dark as the adult stage is approached. The length 
averages 10 mm. and the thickness 5 mm. The entire ventral surface 
is sparsely covered with short, stiff hairs. The pupa occupies a 
smooth-walled cell from 1 to 3 inches below the surface of the ground. 
Nearly a month is spent beneath the ground by the insect in the pre- 
pupa, pupa, and young adult stages and then it emerges as a fully 
developed beetle and seeks the branches of a host tree. 
