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NEUROPTERA, Myrmeleontidae -- <Images> & <Juveniles> Description
This family includes the well-known ant lions, named thus because
of the habit of larvae feeding mainly on ants and their ferocious appearance
and manner of attack. Larvae are also
sometimes called "doodlebugs."
The genus Myrmeleon is
highly specialized, and because of its cosmopolitan distribution and
abundance, is the dominant group in the Neuroptera with the possible
exception of Chrysopidae. There are
ca. 89 species in North America, being most abundant in the South and
West. Adults resemble damselflies,
with long slender abdomens. However,
they differ in being softer-bodied and having rather long clubbed antennae
and in possessing a different wing venation.
They are feeble fliers that are frequently attracted to lights. The wings are either clear or irregularly
spotted. Reaumur (1742) published an early detailed account of the
behavior of Myrmeleon carius L., the accuracy of which was
verified by subsequent researchers.
Wheeler (1930) provided a review of the biology and behavior of this
species. The eggs are small, oval in
outline, and are laid during autumn in small groups, adhering end to end, in
the sand. Hatching occurs shortly
thereafter, and a feeding period occurs before hibernation. The young ant lion is slender, with
conspicuous mandibles and a tough integument, which is essential not only for
defense but for protection against desiccation. There are several types of setae on the dorsum which serve to
transmit the stimuli from falling sand particles to indicate the presence of
prey in the pit. The formation of the pit by the larvae is only during
nighttime. First a circular groove is
made in the sand, which indicates the pit margin to be formed. The larva moves backward, using its head
and closed mandibles to throw the sand from the inner border of the groove to
the outside. The circle that is
followed in this process is gradually narrowed, thus reducing the cone of
sand in the center and deepening the furrow.
The pit is finally completed, and the larva takes position at the
bottom, with the entire body except the mandibles covered with sand. Here it awaits the coming of prey, which
is seized as soon as it tumbles to the pit bottom. If not within reach of the mandibles, it is showered with sand
until its struggles bring it nearer.
Prey is killed very quickly, and its body juices sucked out. The remains are then removed from the pit
by either throwing or dragging. There are 3 larval instars, not differing appreciably in
character, though the body becomes more robust toward maturity. The developmental period is uncertain but may
extend over several years. Larvae are
capable of existing for very long periods without food. They mature in late spring or early
summer, and the spherical double-walled cocoon is then spun beneath the
sand. Pupation occurs ca. 1 week
later, and the adults emerge in 4-6 weeks.
The pupa cuts a circular opening in the cocoon wall with its mandibles
and comes to the surface of the sand before casting its skin. In India the behavior of M. contractus
Wlk differs from other members of the genus in not forming pits in sand
(Gravely & Maulik 1911). Instead
the trunks of mango trees which are coated with dried mud are inhabited, and
the larvae are usually found on the surface or in shallow depressions. The cocoon is formed in a crevice in the
bark, and the adult emerges from the pupal skin, leaving the latter extruded
from the opening. References: Please refer to <biology.ref.htm>, [Additional references
may be found at: MELVYL
Library] |