OF THE FARM AKD GARDEl^. 



85 



THE POTATO-STALK WEEVIL. 



(Baridius trinotatus, Say). 



This insecfc is more peculiarly a soutliern species, occur- 

 ring abundantly in tlie Middle States, and in the more 

 southerly parts of Indiana and Illinois, and also in Mis- 

 souri; but, according to Dr. Harris, being totally un- 

 known in New England. The female beetle (fig. 55, c), 

 deposits a single egg in an oblong slit about one-eighth 

 inch long, which it has previously formed with its beak 



in the stalk of the po- 

 tato. The larva sub- 

 sequently hatches out, 

 and bores into the 

 heart of the stalk, al- 

 ways, according to 

 Miss Morris, of Penn- 

 sylvania, who was the 

 first to notice it, pro- 

 ceeding downwards to- 

 wards the root. When full grown, it is a little over one- 

 fourth inch long (fig. 55, a), and is a soft whitish, legless 

 grub, with a scaly head. Hence it can always be readily 

 distinguished from the larva of the Stalk Borer, which has 

 invariably sixteen legs, no matter hoAV small it may be. 

 Unlike this last insect, it becomes a pupa (fig. 55, Z*), within 

 the potato stalk which it inhabits ; and it comes out in the 

 beetle state about the last of August or the beginning of 

 September. The stalk inhabited by the larva almost 

 always wilts and dies. So soon as the vines first wilt, 

 they should be pulled up and burned. The perfect bee- 

 tle, like many other snout-beetles, must of course live 

 through the winter to reproduce its species in the follow- 

 ing spring. 



Miss Morris found that " in many potato fields in the 

 neighborhood of Germantown, Penn., every stem was in- 



Fig. 55.— POTATO-STALK WEEVIL,, 

 a, Larva ; h. Pupa ; c, Weevil. 



