THE CULTIVATOR. 
277 
ENTOMOLOGY. 
The Dragon Fly. —In a late report of the doings of 
the New-York Farmer’s Club, it is mentioned that some 
grubs were presented, having a “ singular growth, appa¬ 
rently like the root of some vegetable, proceeding from 
the neck,” &c. A distinguished member of the Club 
gave it as his opinion that the grubs were the larvse of 
the Dragon fly— libellula. 
That vegetable excrescences sometimes proceed from 
the bodies of insects, is a fact, not perhaps generally 
unown; and though these productions have been found 
on several kinds of insects, yet we should hardly suppose 
they could exist in the larvae of the Dragonfly; and from 
the economy of that insect, we cannot but view the idea 
that they have thus been found, as erroneous. The Dra¬ 
gon fly, in the first stages of its existence, lives wholly 
in the water, and it is hardly reasonable to suppose that 
while in that element, this vegetable excrescence would 
be produced. We have had some opportunities for learn¬ 
ing the habits of this insect, and have often seen it in all 
its stages, from the first appearance of the larvse in the i 
water, to the perfect fly. The eggs are protruded from 
the parent fly immediately into the water, where they soon 
hatch. When the larvse is full grown, it emerges from 
the water, and fastens itself to some object near at hand.! 
In a short time the shell is burst asunder, and the beauti-! 
ful fly comes forth. In a few hours, the wings become 
extended and dried, and the insect commences its flight. 
We have sometimes taken these grubs just as they were 
coming out of the water, placed them in a warm airy 
situation, and in less than twenty-four hours have seen 
the fly come from them. Thus in the space of a single 
day, an aquatic animal, disgusting and revolting in its ap¬ 
pearance, is transformed into one of the most beautiful 
inhabitants of the air! 
It is supposed that the insect lives at the bottom of the 
water for a year or more. “ Its mode of locomotion 
while in this element,” (says the Natural History of In¬ 
sects, pages 214, 2]5,) t£ is curious; for though it can 
move in any direction, it is not by means'of feet or any 
direct apparatus that it moves, but by a curious mechan¬ 
ism, which has been well illustrated by Reaumur and Cu¬ 
vier. If one of these nymphs be narrowly observed in 
water, little pieces of wood and other floating matters 
will be seen to be drawn towards the posterior extremi¬ 
ty of the insect and then repelled; at the same time that 
portion of its body will be observed alternately to open 
and shut. If one of them be placed in water which has 
been rendered turbid by milk, or colored with indigo, 
and then suddenly removed into a more limpid fluid, a 
jet of the colored water will be seen to issue from the 
anal extremity of the libellula, to the extent sometimes 
of several inches; at the same time the force with which 
the column is ejected, propels the insect in the opposite 
direction, by virtue of the resistance with which it meets. 
Hence it appears that it is by means of its respiratory system 
that the creature walks—a strange and anomalous combi¬ 
nation of functions in one organ. 
“Ifthe insect be taken out of the water, held with its 
head downwards, and a few drops of that fluid poured on 
its tail, that which was a mere point will immediately 
open and display a cavity: at the same time the body of 
the insect, which was before flat, will be observed to be 
enlarged and inflated, and if held up to the light, semi¬ 
transparent : moreover, something solid will appear to be 
displaced by the water, and driven towards the head. 
This solid mass will shortly descend, obscure the trans¬ 
parency of the lower portion of the body of the insect, 
lessen its diameter, and, when it does so, a jet of water- 
will issue from the vent. It is clear, then, that the abdo¬ 
men of the libellula is a syringe, the piston of which be¬ 
ing drawn up, of course the pressure of the fluid fills up 
the vacuum, and, when pushed down, expels the water. 
To ascertain the fact, Reaumur held the insect in his 
hand, and when he saw its body inflated, cut it immedi¬ 
ately with a pair of scissors, and found it unoccupied with 
solids. He watched when the jet of water was expelled 
m another, and as soon as the body was darkened and les¬ 
sened in diameter, he clipped it, and found the cut por¬ 
tion occupied by solids. There is no doubt, then, that 
the abdomen contains a moveable piston, and this piston 
is composed of the air tubes.” 
During its existence in the water, the Dragon fly lives 
on the larvse of the gnat, and other aquatic insects. Af¬ 
ter its metamorphosis, it feeds on gnats, musketoes, flies, 
&c., of which immense numbers are devoured. A large 
one has been seen to spread consternation among a swarm 
of common house flies. Entering a room and pursuing 
its prey with a ferocity equal to that of the hawk or 
eagle, numbers of the fly are soon caught, and the rest 
taking ready warning by the fate of their comrades, es¬ 
cape fx-om the fangs of their terrible enemy, by the near¬ 
est door or window. 
The May-Bug and Horn-Bug. —But let us re¬ 
cur again to the vegetable excrescences on insects 
spoken of above. In some sections of the countxy, 
the belief is quite common that a kind of worm pro - 
duces blackberry bushes. The insects which are thus 
strangely supposed to be the origin of such a production, 
are the larvse of either the horn-bug , (Lucanus caprcolus ,) 
or the May-bug , (Melolontha vulgaris ,) both being gene- 
rally confounded under the name “ white grub.” The 
erroneous idea to which we allude, probably originated 
in the circumstance of a kind of fungus having been 
found proceeding from the larvse of one of these insects» 
We have more than once chanced to find the larvse of the 
horn-bug thus affected. This insect is found in the de¬ 
caying stumps of trees, particularly the oak and apple- 
tree, and also in door-yards where the chips and rubbish 
from hard wood have been suffered to accumulate and rot. 
Blackberry bushes are very likely to start up in fields 
around old stumps, and these stumps being the natural 
haunts of the horn-bug and its larvse, it is natural to sup¬ 
pose that in eradicating the bushes, worms might be 
found having the excrescence mentioned, and with the lit¬ 
tle knowledge of such subjects which too often prevails, 
and without any examination, the strange theory alluded 
to was adopted. 
This fungus is said to have been sometimes found on 
the larvse of the May-bug, (Melolontha)—it should be re¬ 
marked, however, that though the larvse of the horn-bug 
is considerably larger than that of the May-bug, yet their 
appearance is so similar, that without particular observa¬ 
tion, the one might be mistaken for the other. It should 
also be borne in mind that the places where these vege¬ 
tating insects are most!j r found, are the natural haunts of the 
horn-bug, but not of the May-bug—the larvse of the latter, 
instead of subsisting, like that of the hom-bug, on decaying 
wood, feeding on the roots of gi’ass and other living plants. 
From all these circumstances, we are inclined to believe 
that the larvse of the horn-bug, ( Ducanus ,) has some¬ 
times been mistaken for that of the May-bug, ( Melolontha.) 
In all the instances we have known, the worms on 
which these excrescences have been seen, were not only 
dead but in a state of decay; yet we are aware the belief 
is by some entertained, that the 3 r are found in the living 
insect, whose death it is supposed, is ultimately produced 
in consequence; though we do not recollect any well au¬ 
thenticated instance of the kind. It is admitted however, 
that in living insects of other kinds, productions of a si¬ 
milar nature have been found. 
A word in regard to the habits of these insects. The 
horn-bug, in all its stages, is to the farmer a harmless 
insect—subsisting, as we have before said, on decaying 
wood. Vei’y different is the chai-acter of the melolontha, 
or May-bug. A more formidable enemy to field crops 
is scaicely to be found among the insect trib.es. The pa¬ 
rent bug or beetle, deposits eggs to the numbei', it is said, 
of nearly one hundred, in the ground, usually in the month 
of June, in this latitude. It remains in the ground, ac¬ 
cording to Kollar, five, or in some instances, six years, 
living on the roots of whatever cultivated plants or grass¬ 
es it may come in contact with. It lies dormant like the 
ant, in winter, but revives and resumes its ravages with 
the warmth of spring. It is sometimes very desti’uctive 
on grass grounds. Some twelve or fifteen years ago, it 
prevailed in some sections of this counti-y to an alarming 
extent. The roots of grass were in some places so com¬ 
pletely eaten off, an inch or two from the surface of the 
ground, that the turf, for rods together, could be rolled up 
like a carpet. We recollect seeing a piece of ground of 
