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 larvse 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 larvse 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 IS 



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. 

 Sept 



23 



9 



19 



6 



24 



3 



20. . 



7. . 



25. 



1 



21 



8 



9 



10 



11 



12 



26 



1 



22 



27 







23 



28... 







24 



29. 









30 







26 



13 



14 



31 







27 



1. . 







2S 



15 



16 



17 



2 



3 



29 



3... 







30 



4. . 



4 



31 



IS 



19 



20 



5 









Total 





2 



464 



3 



21. 







4 



22.. 











As set forth in Table 1, 464 larvse 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 larva?, 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. 



The pupa (PI. Ill, f) is creamy white, the color deepening and 

 the eyes becoming dark as the adult stage is approached. The length 



irages 10 mm. and the thickness 5 mm. The entire ventral surface 



is sparsely covered with short, stiff hairs. The pupa occupies a 



loth-walled cell from 1 to 3 inches below the surface of the ground. 



Nearly B month is spent beneath i\u- ground by tlie insect in the |>iv- 



pupa. pupa, and young aduh stages ;md (hen it emerges as a fully 



developed beetle and seeks the bnmrhes of a host tree. 



