30 



Larvae pass the winter at varying depths, according to the soil and 

 the degree of its hardness. In a large jar, full of moderately moist 

 sand, in which chestnut " worms" have been placed by the writer, the 

 larvae have penetrated to a depth of 9^ inches in a possible 10 inches. 

 They make cells considerably larger than themselves, so that they 

 have ample room to move about. The larger cells of probosddeus are 

 half an inch long and about one-sixth of an inch in height. As a rule, 

 the larvae rest on their backs in a moderately curved position. Ordi- 

 narily the} 7 remain in perfect quietude even in a moderately warm 

 temperature, but respond to stimulus. 



FOOD HABITS OF SPECIES OF NUT WEEVILS. 



Of the eight species of nut weevils of the genus Balaninus known 

 to inhabit America north of Mexico, the food habits are approxi- 

 mately known, largely through the investigations of Dr. John Hamilton 

 (1. c). The following summary is given of the observed host plants: 



Balaninus rectus Say, the common 

 chestnut weevil, is nearly confined 

 to chestnuts and chinquapins, having 

 been reared only from these nuts, with 

 the exception of a single lot (identified 

 as this species) which bred, from acorns 

 from Arizona. It appears to be the 

 only species affecting chestnuts in the 

 extreme northern portion of the United 

 States where Balaninus occurs. 



Balaninus probosddeus Fab. {carya,- 

 trypes Boh.), the chinquapin weevil, 

 depredates chiefly in chestnuts and is 

 quite as great a pest as the preceding 

 in some regions. It also breeds in 

 chinquapin. 



Balaninus quercus Horn affects in 

 about equal numbers acorns of differ- 

 ent species of biennial fruiting oaks, 

 not being found in annuals (white and chestnut oaks). Mr. Fdk. Blanchard has 

 reared this species from acorns of Quercus rubra, and the writer obtained many 

 specimens from the same or a closely related species. 



Balaninus nasicus Say prefers the acorns of the annual fruiting oaks (white and 

 chestnut), depredating sparingly on those of biennials. 



Balaninus caryse Horn has been reared from pecans from Indiana, and has been 

 found so abundantly on hickory as to leave no doubt that " wormy " hickory nuts 

 are also due to the work of the same species. As a rule, however, it does much less 

 injury to these nuts than do the others to acorns and chestnuts. Mr. Blanchard has 

 also reared this species from shagbark hickory. 



Balaninus uniformis auct. prefers the acorns of biennials, but depredates occasion- 

 ally on chestnut oak. In some localities, at least during certain seasons, as, for 

 example, at Ithaca, N. Y., this species is the most abundant, while in western Penn- 



Fig. 9. — An acorn weevil, Balaninus victoriensis: a, fe- 

 male, dorsal view; b, same, lateral view; c, head of 

 male, showing antenna and rostrum, four times 

 enlarged (original). 



