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Both of these insects occur more or less abundantly in the tobacco 
fields over the entire tobacco-growing regions of the United States. 
In certain localities one species will be much more abundant than the 
other, and in other localities the numbers will be more evenly divided. 
In general, it may be said that celeus is the more northern species, and 
is found more abundantly in the more northern tobacco fields, while 
farther south carolina is apt to be much the more common. In the 
tobaeco-growing regions of Connecticut, for example, according to 
Professor Fernald, celews is the more common tobacco worm, while in 
Florida the reverse condition holds. Both species occur from Canada 
to Florida, and as the region of tobacco culture fails in the North, 
both species feed upon tomato. Carolina extends its range into the 
West Indies and South America, but celews is not found south of 
Florida. 
The life histories of both species are practically identical. Vary- 
ing in date, according to the climate, the moths make their appear- 
ance, working their way out of the underground pupe, or chrysalids, 
from May 1 well on into June, pair, and lay their eggs singly on the 
undersides of the leaves. The young caterpillars hatch from these 
eggs, which, by the way, are laid in the dusk of the evening, in from 
four to eight days, according to Professor Alwood’s observation of 
carolina. In the course of their growth they cast their skin four 
times, and in less than a month become full grown, burrow into the 
soil, and transform to pupe. 
The number of generations in a year varies in different localities. 
In the greater part of the tobacco-growing region planters have recog- 
nized that there are two ‘‘ecrops” of the worms. This holds in por- 
tions of Maryland. At Blacksburg, Va., Professor Alwood has found 
that one ‘‘crop” is normal, and that there are occasional indications 
of a second ‘‘crop,” or generation. In Florida, where the moths make 
their appearance early in May, according to Professor Quaintance, the 
first generation of caterpillars is not particularly destructive, but the 
second generation, which appears during July, causes the most dam- 
age. <A third generation is normal, and probably a fourth, although 
in July caterpillars of various sizes may be found in the fields at one 
time. The retardation of development in some individuals, and ae- 
celeration in others, bring about an intermingling of generations, which 
is always marked in insects in the South where the number of genera- 
tions exceeds three. In Cuba, where the carolina horn worm is said 
to be a severe pest to the tobacco industry, there is probably an even 
larger number of generations. 
Actual damage done by horn worms varies greatly in different 
seasons. Frequently, for a number of years, they will not be too 
abundant to be kept down readily by hand picking, and then will 
come a season in which they are so numerous that it is very difficult 
to save the crop without incurring a prohibitive expense. Again, 
