6 



Fig. 7. — Chinquapins, showing injury by les- 

 ser chestnut weevil at left; of larger weevil 

 at right. Enlarged (original) . 



larva^ bore through the burr. On leaving the nuts they burrow into 

 the earth to depths varying from 2 to about 8 inches, according to the 

 lianhiess of the soih If confined in soft earth or sand they penetrate 

 still deeper. The larval period probably lasts from three to five Aveeks 

 in the nuts, and about ten months in the earth, pupation taking place 



within three weeks of the issuance 

 of the beetle, the latter remaining 

 several days in the earth before 

 appearing above ground. 



The beetles do not fly readily, but 

 cling tightly to their resting place 

 or drop when disturbed ; yet, as 

 Iheir bodies are not heavy and their 

 wings strong, they are obviously 

 able to cover considerable distances, 

 especially with the wind. Ordina- 

 rily, however, they are sluggish, 

 like most other weevils, and probably do not go far from the vicinity 

 of the trees which have sheltered them as larvae, although they 

 undoubtedly migrate when food is scarce. 



NATURAL ENEMIES. 



A natural enemy of the nut weevils is known, a small four-winged 

 wasplike fly, the braconid parasite Urosigalphus arniatuH Ashm., 

 which develops in the body of the larva." 



METHODS OF CONTROL. 



The most practical remedy for nut weevils that can be suggested is 

 the early desti'uction of the " worms '' in the nuts by means of bisul- 

 phid of carbon and the observance of clean orchard management and 

 other cultural methods. It may be well to preface the discussion of 

 these methods with a statement of the uselessness against nut weevils 

 of ordinary measures employed in the control of similar insects. 



Unsatisfactory Methods. 



Stomach poisons. — The peculiar structure, in the nut weevils, of 

 the mouth-parts (minute mandibles placed at the end of a beak nearly 

 as fine as horsehair and as long or longer than the body) is almost 

 sufficient proof in itself that these insects do not feed on leaves, but 

 depend for sustenance on the substance of the growing nuts. The 

 beetles first appearing feed on the undeveloped, very young nuts and 

 the juices within the husk. There is, therefore, no seeming possibility 

 of reaching them with a spray of Paris green or other stomach poison, 



" Two other insects are associated with the weeA'ils and are probably also 

 their enemies, a proctotrypid i>Mrasite, Trichnxis rufipeti Ashni., and a predatory 

 reduviid bn^. Acliolhi mill tin inno-sa DeG. 

 [Cir. 00] 



