Leng: Nut and Acorn Weevils "jy 



of the oviposition, depth of larval chamber in the earth, and 

 natural enemies have been furnished by Brooks and are of 

 interest. 



The female uses the beak to drill a hole in the nut. It is a 

 slow operation, depending on a partial revolution of the head and 

 the bracing of the body by the legs, the head being turned from 

 side to side as far as the connection with the thorax permits. 

 Her position during the drilling is a precarious one, and if she 

 loses her foothold she is liable to be hung by her beak and die 

 in that position, as figured by Brooks (loc. cit. p. i68 E). The 

 drilling completed, she turns around and inserts an ovipositor, 

 long and threadlike and concealed within the body at other times, 

 through which the egg is passed. The operation has been timed 

 and found to occupy about an hour, not an excessive period to 

 any one who knows the bonelike hardness of a mockernut shell. 



The depth to which the larva penetrates the ground varies 

 from i^ to lo inches, according to the nature of the soil, its 

 moisture, etc. An oval chamber is made within which pupation 

 takes place, usually about ten months later. There are, how- 

 ever, according to Brooks belated larvae which stay in the ground 

 two years, either from feebleness due to late oviposition, which 

 in some species is bound to occur from the females continuing to 

 deposit their eggs over a long period, or from lack of sufficient 

 rain to soften the ground. 



Throughout their lives these larvae are pursued by enemies. 

 Many are parasitized and never reach the earth. Others are 

 devoured by squirrels. Mr. W. T. Davis has informed me of 

 an interesting original observation on the method by which the 

 squirrels detect the presence of larvae in acorns, nibbling a 

 small hole in the base, whereby their sense of smell tells them 

 which acorns to discard as containing no larvae. During their 

 long sojourn in the earth they are the victims of predaceous 

 creatures of various kinds, especially the short-tailed shrew, 

 which excavates tortuous galleries beneath the tree in its search 

 for hibernatinsf larvae. 



