Rabbit Bots 
CUTEREBRA CUNICULI, A RABBIT BOT FLY GREATLY ENLARGED. ACTUAL 
SIZE, 1 
W ORMY rabbits and squirrels 
have long been known to hunt¬ 
ers, but the story of these 
bots is a mystery to most of them. 
Most hunters are familiar with dark- 
colored, fleshy grub that is often found 
beneath the skin of a rabbit, or they 
may have found several of these large 
worms or grubs in the game bag, that 
had emerged from the carcasses of their 
game. 
These grubs are the larvae or young 
stages of bot-flies; insects that are sel¬ 
dom observed, and practically unknown 
to anyone excepting an entomologist. 
In trailing this insect, first look for 
rabbit signs—a “squat” or a runway 
through the tall grass or along the 
fence. 
During the summertime the flies fre¬ 
quent the open sunny places, or hide 
themselves in the grass and weeds, in 
situations where they are most likely to 
find their victims. These flies resemble 
a large bumble-bee, and are probably 
mistaken for bees by most persons. 
They fly quietly along about a foot 
above the gound, zigzagging here and 
there in restless manner, avoiding an 
object in their path, some moving sha¬ 
dow in the way; apparently looking for 
a sleeping rabbit, a nest or feeding 
ground. 
CUTEREBRA BUCCATA FAB. ADULT BOT 
FLIES TWICE ENLARGED 
INCH 
It alights upon a stone to rest a bit 
—let us examine it critically. It is 
about an inch long, with two large 
smoky-brown wings; the head is black; 
the thorax above and the first segment 
of the abdomen are covered with dark 
yellowish hair; the abdomen is bluish- 
black, shining; like all insects it has 
six legs; it is one of our larger two¬ 
winged flies, belonging to the Order 
Diptera, and in technical terms it is 
called Cuterebra cuniculi (Fig. 1). Cu- 
terebra, the generic name, means “skin 
borer.” 
If we were able to catch a specimen 
we would find that it could neither bite 
nor sting; it is likely that it cannot 
even eat, the mouth parts are so poorly 
developed; its sole function in life is 
to mate and lay eggs. 
Were it possible to follow a female 
of one of the bot-flies we would find it 
equal to our hound for trailing rabbits, 
and we might possibly learn just how 
the eggs are laid. This matter has 
never been fully solved, however, but 
it is supposed that the eggs are fast¬ 
ened to the plants upon which the rab¬ 
bits feed, are swallowed with the food, 
and the small larvae or bots upon hatch¬ 
ing from the eggs are able to gain ac¬ 
cess to the location where they are com¬ 
monly found. The probable method is 
through the stomach and tissue to a 
point beneath the skin. 
The full-grown worm or larvae is a 
thick, gray or dark-colored, fleshy crea¬ 
ture about one inch long (Fig. 2A). It 
is usually found beneath the skin on the 
back, belly or shoulder, where it forms 
a large tumor or cyst. Each cyst is 
open to the outside through a hole in 
the skin; the tracheal openings of the 
respiratory system being located at the 
anal extremity of the grub and are in- 
Parasitic Insects Attacking 
Rabbits and Other Small 
Animals 
By A. B. CHAMPLAIN 
serted through this hole for the purpose 
of breathing. 
The body of the grub is provided with 
rows of spines in place of legs to assist 
in locomotion, and it lives in and feeds 
upon the pus and matter caused by its 
irritating presence in the tumor, and 
possibly somewhat on the blood of its 
host. 
These bots or larvae become full 
grown about the time of the first frosts, 
when we are thinking about hunting 
rabbits. During the fall time they 
emerge from the wounds in their hosts 
and fall to the ground where they bury 
themselves in the earth. When they 
have reached the depth that is satis¬ 
factory to them, pupation takes place, 
and here they remain throughout the 
winter in this quiescent state (Fig. 
2B). 
The pupae in general resemble the 
larvae or grubs, but the skin on the out¬ 
side becomes hard and brittle. How¬ 
ever, within there is a great change 
taking place; the larvae inside has as¬ 
sumed quite another shape. The pupal 
shell or “mummy,” as we shall arbi¬ 
trarily call it on account of its dried-up 
appearance, becomes lined inside with 
a silken membrane, and resting upon 
this smooth interior we find a perfect 
fly forming. 
If we were lucky enough to observe 
this mummy the following spring or 
early summer, we would find it crack¬ 
ing along the top; later a cap or lid 
would become apparent; then, at the 
(Continued on page 716) 
A B 
(A) LARVA OF CUTEREBRA 
(B) PUPAE OF CUTEREBRA 
