250 TOBACCO LEAF. 



spreads into all regions where the new host plant is 

 cultivated. This has been the history of the Colorado 

 potato beetle, which originally subsisted upon another 

 solanaceous weed. 



Description of the Tobacco Miner. Gelechia pici- 

 pellis, Zett. General color, yellowish gray. Head and 

 thorax paler than wings, inclining to cream color. 

 Palpi simple, not exceeding the vertex. Primaries 

 variegated, with a few smoky streaks and a marginal 

 row of minute black spots at base of cilia. Wing 

 expanse 0.45 to 0.50 inch. Length 0.20 inch. (After 

 Miss M. Murtfeldt, 1881.) The insect belongs to the 

 natural order Lepidoptera, sub-order of moths. Family 



FIG. 70. TOBACCO WORM, LIFE SIZE. 



of Teneids, of which the more important are the clothes 

 and fur moths, and the Angonmois grain moth or "Fly 

 weevil" (Gelechia Sitotroga cerealella), so destructive 

 to corn and grains in the crib. The latter species is 

 very closely related to and greatly resembles our tobacco 

 miner. 



Remedies. None have been tried as yet. From the 

 nature of the case, the treatment must be preventive. 

 The parent moth deposits her eggs within the substance 

 of the leaf or stem of the plant. The resulting cater- 

 pillar eats the green matter of the leaf, leaving both 

 epidermes intact. These surfaces, in the case of to- 

 bacco, are oily and will readily shed any liquid, and 



