Intro:
I
chose to research and observe the ant lion because it is a little known
creature that also happens to be quite fascinating. Most people wouldn’t even
know that this brutal ant-killer with 4mm jaws lurked beneath the sand.
B. Anatomy:
Dimensions:
Larvae:
Length:
14mm
Height:
3mm
Width:
6mm
Adult:
Length:
40mm
Height:
6mm
Width:
80mm
Speed:
1cm/2sec (avg.)
Number
observed: Three
C. Environment:
Flora:
None in particular.
Temperature:
Doesn’t matter, as long as there is an adequate food source.
Location:
Prominently southern United States, Europe, and Africa
Sunlight
or shade? Shade
Moisture:
The larvae cannot live in moist ground. Moisture doesn’t affect adults.
Soil:
The larvae require fine soil or sand to make their pits in.
Response
to stimuli:
Light:
No response to a rapidly blinking, bright light.
Poke
(sharp object): Moves backwards quickly.
Flipping:
Stays still for a moment, then flips itself back over and flees.
Vibration: No effect, unless it’s close to them, then
they get excited and/or flee.
Eyes:
Two
Facets:
Six
Antennae:
Larvae have none; adults have long, club-shaped ones.
D. Locomotion and
defense:
The
ant lion in the larval stage has six legs that specialize in moving backwards.
The front pair is smaller than the others and can easily be tucked underneath
the ant lion. The mandibles are approximately 4mm long and curved inward with
several inner pincers. They have visible hairs all over their backs, probably
to aid in anchoring them to the side of their pit. The adults have wings that
are about 40mm long, but are not very strong flyers.
E. Nutrition and
reproduction:
The
larvae use shallow, cone-shaped pits to capture their prey (usually ants, but
can be spiders, caterpillars, or beetles). The insect falls into the pit and
is unable to climb up the loose sand on the sides of the pit. The ant lion
lies buried at the bottom of the pit and catches its prey with its strong,
piercing mandibles. The larvae then secrete digestive enzymes through the
mandibles into the prey. After the ant lion sucks out the soft tissues of the
prey, the leftovers are discarded by being tossed out of the pit. The solid
wastes from the digestion of prey accumulate within the ant lion’s body for the
entire larval stage, but liquids are released into the surrounding sand. The
length of the larval stage is determined by the availability of food. The
larvae can live for longer than three months without feeding, but at the cost of
body mass.
The
ant lions reproduce in adulthood, which only lasts 20 to 45 days. At night,
they congregate around lights to find a mate. Then, the male will hang from
the female by his genitalia and copulate. After nearly two hours, the male
will detach and the female may feed on his spermataphore. The female will lay
the eggs in a sandy (usually warm) area beneath the surface.
F. Appearance and
gross anatomy:
Bottom:
Top:
Side:
G. Environment
and stimuli:
Colony of ant lions:
Eyes:
H. Locomotion,
defense, reproduction, and food:
Bottom, parts:
Reproduction:
Capturing an ant:
I. Questions:
- Is
the size of the pit affected by the size of the organism?
- Can
gender be determined in the larval stage?
- What
family are they from?
- What's
a genome?
- What’s
the average weight?
- How
many species of ant lions build pits?
- Will
they attempt to suck a tiny ant or throw it out?
- Can
they be feed manually without a pit?
- Can
they carry diseases?
- How
long can they survive without feeding until death?
J. Works Cited:
Swanson,
Mark “Antlion Pit: A Doodlebug Anthology”. 2002. 7 Oct. 2002 <http://www.antlionpit.com/index.html>.
Armstrong,
W. P. “antlions”. Wayne’s Word. 8 Oct. 2002 <http://waynesword.palomar.edu/pljuly97.htm>.
Time:
2.5 weeks observing, 12 hours writing/editing
Additional
Resources:
antlions.avi - short clip (1:33) recorded from
Animal Planet showing an ant lion making a pit, catching an ant, and then
discarding it. DivX video/MP3 audio