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Antlion

2007 Schools Wikipedia Selection. Related subjects: Insects, Reptiles and
Fish

                   iAntlion
   An adult antlion, camouflaged on a plank
   An adult antlion, camouflaged on a plank
          Scientific classification

   Kingdom:     Animalia
   Phylum:      Arthropoda
   Class:       Insecta
   Superorder:  Endopterygota
   Order:       Neuroptera
   Superfamily: Myrmeleontoidea
   Family:      Myrmeleontidae

   Antlions are a family of insects in the order Neuroptera, classified as
   Myrmeleontidae, from the Greek "myrmex", meaning "ant", and "leon",
   meaning "lion". Strictly speaking the term antlion applies to the
   larval form of the members of this family. Antlions are worldwide in
   distribution, most common in arid and sandy habitats, and can be fairly
   small to very large (wingspan range of 2-15 cm). Antlions are
   omnivorous. The antlion larvae eat ants and other insects, while the
   adult antlion eats pollen and nectar.

   The antlion larva is often called a "'doodlebug"'. One theory is that
   it gets this name from the odd winding, spiralling trails it leaves in
   the sand while looking for a good location to build its trap. These
   trails look like someone has doodled in the sand.

   The adult antlion has two pairs of long, narrow, multi-veined wings in
   which the apical veins enclose regular oblong spaces, and a long,
   slender abdomen. Although they greatly resemble dragonflies or
   damselflies, they belong to an entirely different order of insects.
   Antlions are easily distinguished from damselflies by their longer,
   prominent, apically clubbed antennae and different pattern of wing
   venation. They also are very feeble fliers and are normally found
   fluttering about in the night, in search of a mate. The adult is rarely
   seen in the wild because it is typically active only in the evening.

Development

   Closeup of an antlion larva
   Enlarge
   Closeup of an antlion larva
   Closeup of another antlion larva
   Enlarge
   Closeup of another antlion larva

   The life cycle of the antlion begins with egg-laying or "oviposition".
   The female antlion repeatedly taps the sand surface with the tip of her
   abdomen. She then inserts the abdomen into the sand and lays an egg.
   The antlion larva is a ferocious-appearing creature with a robust,
   fusiform body bearing three pairs of walking legs and a prothorax
   forming a slender mobile neck for the large square head, which bears an
   enormous pair of sicklelike jaws (mandibles) with several sharp, hollow
   projections. Depending on species and where it lives, the larvae will
   either hide under leaves or pieces of wood, or dig pits in sandy areas.
   Pupa in cocoon
   Enlarge
   Pupa in cocoon

   The pupal stage of the ant-lion is quiescent. The larva makes a
   globular cocoon of sand stuck together with fine silk spun, it is said,
   from a slender spinneret at the posterior end of the body. These
   cocoons may be buried several centimeters deep in the sand. It remains
   there for one month, until the completion of the transformation into
   the sexually mature insect, which then emerges from the case, leaving
   the pupal integument behind, and climbs to the surface. After about 20
   minutes the adult's wings are fully opened and it will fly off in
   search of a mate. The adult is considerably larger than the larva; they
   exhibit the greatest disparity in size between larva and adult of any
   type of holometabolous insects, by virtue of the adults having an
   extremely thin, flimsy exoskeleton (in other words, they have extremely
   low mass per unit of volume). The adults are reported to live off of
   plant nectar, but some species retain strong chewing jaws similar to
   those of the dragonfly indicating that they also feed on insects.

Pitfall construction

   Having marked out the chosen site by a circular groove, it starts to
   crawl backwards, using its abdomen as a plough to shovel up the soil.
   By the aid of one front leg it places consecutive heaps of loosened
   particles upon its head, then with a smart jerk throws each little pile
   clear of the scene of operations. Proceeding thus it gradually works
   its way from the circumference towards the centre. As it slowly moves
   round and round, the pit gradually gets deeper and deeper. When the pit
   is completed, the larva settles down at the bottom, buried in the soil
   with only the jaws projecting above the surface, often in a wide-opened
   position on either side of the very tip of the cone.

Trapping prey

   Sand pit trap of the antlion
   Enlarge
   Sand pit trap of the antlion

   Since the sides of the pit consist of loose sand they afford an
   insecure foothold to any small insects that inadvertently venture over
   the edge, such as ants. Slipping to the bottom, the prey is immediately
   seized by the lurking ant-lion; or if it attempts to scramble again up
   the treacherous walls of the pit, it is speedily checked in its efforts
   and brought down by showers of loose sand which are jerked at it from
   below by the larva. Antlion larvae are capable of capturing and killing
   a variety of insects, and can even subdue small spiders. The
   projections in the jaws of the insect are hollow and through this the
   larva will suck the fluids out of its victim. After consuming all the
   contents, the lifeless, dry carcass is flicked out of the pit, and the
   pit is readied once again. An average-sized larva digs a pit about 2
   inches deep and 3 inches wide at the edge. Amazingly, this behaviour
   has also evolved in a family of flies, the Vermileonidae, whose larvae
   dig the exact same sort of pit and also feed on ants.
   Adult Antlion
   Enlarge
   Adult Antlion

   Antlions are especially abundant in soft sand beneath trees or under
   overhanging rocks. Apparently the larvae prefer dry places that are
   protected from the rain. Eventually the larva attains its maximum size
   and undergoes metamorphosis. The entire length of time from egg-laying
   to adulthood may take two or three years due to the uncertainty and
   irregular nature of its food supply. When it first hatches, the tiny
   larva specializes in very small insects, but as it grows larger, it
   constructs larger pits and thus catches larger prey.

   Although antlion larvae have a ferocious appearance, they are
   completely harmless to humans. In fact, there are those who keep them
   as pets.

   In certain species of Myrmeleontidae, such as Dendroleon pantheormis,
   the larva, although resembling that of Myrmeleon structurally, makes no
   pitfall, but seizes passing prey from any nook or crevice in which it
   shelters.

Additional information

   The exact meaning of the name ant-lion (French fourmilion) is
   uncertain. It has been thought that it refers to the fact that ants
   form a large percentage of the prey of the insect, the suffix "lion"
   merely suggesting destroyer or eater. Perhaps, however, the name may
   only signify a large terrestrial biting apterous insect, surpassing the
   ant in size and predatory habits.
   Retrieved from " http://en.wikipedia.org/wiki/Antlion"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
