37 



be collected. Hence, to secure clean culture, it is imperative to plant 

 or graft only on perfectly smooth soil, first, for economic or commer- 

 cial reasons, and, second, to permit the collection of all of the nuts, 

 leaving none for the propagation of the weevils. 



Careful harvesting. — One of the most feasible remedies and one that 

 had been advised for years is to pick all of the chestnuts from the 

 ground, taking the greatest care to leave none, and either place them 

 in tight boxes or in barrels, where the grubs when they issue will not 

 be able to reach the ground, or fumigate with bisulphid of carbon 

 before shipping to market. The grubs crawl out soon after the nuts 

 have been gathered, and as they require a considerable degree of 

 moisture they will, if kept in closed receptacles, die without being 

 able to reach the ground. The trouble is that enough nuts are usually 

 left in the orchards or in the woods owned by the farmer or his 

 neighbors to serve for the propagation of the insects for following 

 years. In order to make this method of treatment thorough it will 

 be necessary to secure the cooperation of neighboring landowners, 

 not only of those who grow chestnuts for market but of all who may 

 own woodland containing chestnut and chinquapin, which would serve 

 for the continued propagation of the insects. a 



The collection of remnants is no great hardship, and there are 

 probably cases where it would be profitable to allow pigs the run of 

 pecan orchards to destroy what nuts remain after the main crop has 

 been harvested. In the absence of a sufficient number of the nuts it 

 is not probable that pigs would learn to root for the grubs, if these 

 have left the nuts and are in the ground, because of their small size 

 and the depth to which they are able to penetrate. 



It has been suggested that turkeys might be useful in destroying the 

 chestnut weevils, but it does not seem probable that this remedy would 

 be a safe one. If the turkeys were allowed to roam through the 

 orchards when the burrs are first opening the beetles are also there, 

 and if the birds attempted to devour them they would probably soon 

 desist, owing to the strong outer shell of the beetle and its long, strong, 

 and spiny legs. If many beetles were swallowed, they might cause the 

 death of the turke}~. Again, the hogs would probably not devour the 

 nuts after having their mouths irritated by the spines of the chestnut 

 husks. 



Cooperation. — Although the results of the observance of clean culture 

 on the lines that have been indicated might not be at once apparent, 

 it can be only a matter of time, if this work is systematically carried 

 out hx all growers over a considerable territory, when infestation 

 would be greatly decreased. An important point to ascertain is as to 



a It seems probable that the two chestnut weevils under consideration confine their 

 attacks to chestnut and chinquapin, and that the acorn-feeding form from Arizona 

 identified by Hamilton as Balaninm rectus will prove a different species. 



