52 
THE CORN OR FLY-WEEVIL.-NO. 1. 
THE CORN OR FLY-WEEVIL.—No. 1. 
The “Farmers’ Cabinet” of the 16th inst., con¬ 
tains a notice of the appearance of a strange in¬ 
sect, which had escaped from some grains of Indian 
corn, in Germantown, Pa., with a letter from Dr. 
T. W. Harris, of Harvard University, who states 
that a similar fact had been observed in Worcester, 
Mas>s., and made known to him about two years 
since; and that it is the same insect that destroys 
wheat in Virginia, and some of the Southern and 
Western States, and appeared in the provinces of 
La Vendee and Angoumois, in the west of France, 
more than 100 years ago. Being a farmer, and 
having suffered greatly from the depredations of 
this insect for many years, I have taken pains to 
observe its habits, more especially to investigate the 
conditions most favorable to its development, and 
the extent of its ravages, the results of which were 
published in the “ Farmers’ Register,” vol. i., pp. 
325 and 463. (a) 
Several insects, very different in their appearance 
and habits, are called by the general name of 
“ weevil,” which has served much to confuse the 
prevailing and erroneous opinions concerning them. 
The insect under consideration, in its perfect state 
is a moth of a dirty, pale-yellow color, about a third 
of an inch in length. Its flight is awkward and 
feeble, and its body is so soft and tender that it is 
liable to be broken from a very slight cause. The 
males and females leave their places of conceal¬ 
ment in wheat stacks and corn-houses, just after 
sunset, and their flight abroad, is well marked by 
the concourse of bats and night-hawks, which are 
engaged in pursuing and devouring them. ( b ) 
In the moth, or perfect state, this insect can do 
no harm to grain; but in the larva or maggot 
state, the grain is not only injured by devouring a 
large proportion of its internal substance, but by 
remaining for a time, therein enclosed, and finally 
leaving its excrescent, cast-off skin of the chrysalis, 
and often, also, the dead moth itself, when the close¬ 
ness of the bulk of grain prevents its escape. It is 
manifest that no insect depredation can be more 
destructive to the value of grain, and that no rava¬ 
ges can be more complete and extensive than where 
these weevils are very numerous. Where the 
climate is favorable to their development, and other 
circumstances are not unfavorable, there is no 
limit to their destructive effects before every grain 
of wheat or corn has been made the food and 
habitation of a disgusting maggot. Such great 
extent of injury, however, is rarely seen, except 
under the most favorable circumstances. When 
Indian corn ripens while the weather continues 
warm, a few weevil eggs are often deposited on the 
upper ends of the ears, which protrude from the 
shuck or husk. These eggs soon hatch and the 
larvae gnaw into the grains, and sometimes undergo 
their transformations in the field, before the coming 
of frost, which is manifest from the perforations 
made by the escaped moths. The earliest kinds of 
corn, of course, are most exposed to the attacks of 
these insects, and hence are objected to, by some, as 
being more liable to be weevil-eaten the following 
year. The eggs which are laid and hatched in 
autumn on new corn, are too few to cause any ap¬ 
preciable damage, could the further propagation be 
arrested. But the eggs, and perhaps the insects, m 
the larva and chrysalis states, if not killed by an 
unusual severity of cold, will remain torpid during 
the winter and spring, and do not begin to reproduce 
before the next summer. In June or July, the first 
brood of moths comes out in very small numbers ; 
and as the corn is usually stored in ears, in open 
cribs, it permits their escape from nearly every 
grain, and likewise a free access to other grains for 
subsequent laying. Like most of the insect tribes, 
it may safely be inferred that the fly-weevil lays a 
considerable number of eggs, and that the progress 
of her progeny is very rapid from the egg to the 
moth. I found that the several stages were passed 
through from September 2d, to October 6th ; and 
in the hotter weather in August, the time probably 
would not have been so long by one-half. In the 
climate of lower Virginia, it may be supposed that 
there are at least five successive generations from 
June to October. In this manner, their propaga¬ 
tion, if not prevented by some means of destruction, 
would be in geometrical progression, increasing by 
a very large ratio ; and their number, at the end of 
a few generations, might increase to an extent that 
would at first seem almost incredible. For instance, 
let us suppose the eggs laid by each female to 
be 200, which is not an extravagant supposition, 
and that four generations are produced during the 
year, exclusive of the parent moth ; allowing half 
the number to be males, and consequently not 
counted, and the result would be as follows:— 
The second generation of females would be 100; 
the third, 10,000; the fourth, 1,000,000; and the 
fifth, 100,000,000. By adding to these 100,000,000 
males, the whole number of the fifth generation 
would amount to 200,000,000 ! The enormous 
magnitude of this number may be better conceived 
when I state there are not so many grains of com 
in 1,100 bushels! 
If, then, this weevil is thus increased in rapid 
and successive generations, it is obvious that the 
best and most sure course for prevention is to 
attack them in the earliest stages of their existence. 
For the destruction of only one female, of the first 
brood may cut off the production of 100,000 in 
after generations, notwithstanding the number de¬ 
stroyed by accident, or enemies, which they 
naturally have to encounter. Fortunately, how¬ 
ever, the prodigious increase of this insect is held 
in check by its frail tenure of life, and its great in¬ 
crease may be as easily restrained by care and 
judgment, as it is extended and rendered ruinous 
by inattention and neglect; and this I propose to 
show in a future number. Edmund Ruffin. 
Marlbourne, Va ., Nov. 29th, 1846. 
(a) In the year 1768, Colonel Landon Carter, of 
Sabine Hall, Va., communicated to the American 
Philosophical Society at Philadelphia, some in¬ 
teresting “Observations concerning the fly-weevil 
that destroys wheat,” which were published in th.e 
first volume of the transactions of that Society, fol¬ 
lowed by some interesting remarks on the subject 
by the committee on husbandry. The same in¬ 
sect has also been known for more than forty years 
