PESTS OF TOBACCO. 251 



they also prevent any powder from penetrating or touch- 

 ing the insect within. It is within these mines that the 

 caterpillar appears to pass its whole larval and pupal 

 life, issuing as a winged moth to lay eggs as before. 

 The number of annual generations is yet unknown, but 

 is probably not less than three. The insect is believed 

 to hibernate in the imago or winged state, though it 

 may also lie dormant, either as caterpillar or pupa, hid- 

 den in the stumps of tobacco or the roots of the bull 

 nettle. The most promising remedy at present is the 

 extirpation of the bull nettle in all tobacco-growing 

 sections, and the prompt plowing under or removal of 

 tobacco stumps as soon as the crop has been gathered. 

 Watch for leaves showing the miner's transparent 

 blotches, and when found, remove and burn them. 



The Tobacco Worm. This is the great arch enemy 

 of the tobacco plant and absolutely sets a limit to the 

 culture of tobacco. It reduces the acreage fully one- 

 half. But for its destructive power six acres might 

 easily be cared for by one man. There is no remedy for 

 them, but to search every leaf and destroy them. The 

 worming of the crop, when they are numerous, is the 

 most disagreeable and tedious work attending tobacco 

 growing. Some seasons there are comparatively few, 

 again, they seem to infest every leaf. Worming has been 

 done so persistently in many places in the Connecticut 

 valley that this pest is well-nigh exterminated. But un- 

 der more careless methods at the South, immense injury 

 is done by the tobacco worm, as may be inferred from 

 the photograph in Fig. 67, of an entire crop utterly de- 

 stroyed by this pest. Fields of tobacco that give prom- 

 ise of making the finest wrappers may be totally ruined 

 for that purpose through a week's neglect in catching 

 the worms. It matters but little how rich the soil may 

 be, or how well cultivated, the crop will be a total 

 failure unless these worms are destroyed. So important 



