36 



Trap crops. — The use of varieties particularly susceptible to the 

 weevils scattered through orchards of other varieties to attract beetles 

 from them where they can be more readily dealt with has been sug- 

 gested/' The reports that have been made of the liability to attack 

 of different varieties of chestnut, however, do not, as a rule, show 

 what varieties are in any noticeable degree immune. On this head 

 Mr, G. H. Powell informs the writer that the Paragon, Cooper, and 

 Ridgely are more affected by weevils than are the Japanese varieties, 

 taken as a whole. 



Jarring the trees. — This remedy was suggested by the late Doctor 

 Lintner, because, as he says, it has been found very effectual with the 

 plum curculio. As a matter of fact, it has not been found fully satis- 

 factory against the plum curculio, and will be found still more diffi- 

 cult, not easier, in controlling the chestnut weevils. The only weevils 

 that can be dislodged are those which happen at the moment to be dis- 

 engaged, crawling from one nut to another, or in search of their mates. 

 Like several other species of insects, these nut weevils remain paired 

 almost continuously and while oviposition is going on. Even when 

 the snouts of the weevils are not buried deep in the husk of a chestnut, 

 their long and very strong legs enable them to maintain a firm hold, 

 which the hardest jarring that the tree could stand would not dislodge. 

 This is not mere theory, but is the experience of collectors, including 

 Mr. Schwarz and the writer. 



PREVENTIVES. 



Choice of location of the orchard. — It is a matter of great importance 

 that the locality in which chestnuts are planted or grafted on old trees 

 be made with reference to the chances of immunity or of injurious 

 attack by nut weevils. As may be readily inferred from what has 

 been said in previous paragraphs, it is highly inadvisable to select for 

 a chestnut orchard a locality in the immediate vicinity of much wood- 

 land abounding in wild chestnut and chinquapin, and perhaps oak, as 

 the first two trees furnish the principal breeding places of these insects, 

 and are therefore a constant menace to successful chestnut culture. 

 To what extent, if at all, acorns furnish food for either chesnut 

 weevil remains to be learned. A prominent chestnut grower, who has 

 suffered considerable losses from weevils, has admitted that native 

 chestnuts are neglected in the near vicinage of his cultivated groves. 

 Mr. H. E. Van Deman, a practical nut grower, has directed the writer's 

 attention to another phase of planting, which is that Paragon and 

 other cultivated varieties are frequently grafted on native chestnuts in 

 rocky and uneven soil, where it is not only impossible to gather a 

 complete crop, but, what is of equal importance, the remnants can not 



flG. Harold Powell (Bull. XLII, Del. Coll. Agr. Expt. Sta., 1898, p. 14.) 



