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Immature Stages of Ascalaphidae


          The larvae of Ascalaphidae are distinguished from the true ant lions by their habit of walking forward rather than backward.  The adults resemble dragonflies but may be distinguished by a long, clubbed antenna.  They are crepuscular or nocturnal in behavior.


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          Ululodes hyalina Latr. of the southern United States and Central America was studied by McClendon (1902).  Eggs are laid in groups of 57-75 in a double row at the end of a twig, and the mass is fenced off slightly below the base by several circles of "repagula" placed on end.  These repagula are thought to be aborted eggs, produced by certain ovarian tubules at the same time that others form normal eggs.  This formation is thought to protect the egg mass from natural enemies.  The incubation period is 9-10 days.


          Larvae hide in depression in soil or under the edges of stones and cover their bodies with sand or dust.  While awaiting prey, the huge mandibles are held widely separated.  The closing of the jaws is seemingly triggered by contact, and the prey is usually paralyzed within seconds by the bite.  The body fluids of the prey are absorbed through a duct formed by the fitting together of curved mandible and maxilla.  There are 3 larval instars, and development takes ca. 62 days.


          Helicomitus dicax Wlk. lays dark brown eggs in single rows, each of which contains as many as 40 (Ghosh 1913).  There are 3 larval instars, the larvae living on the ground surface, beneath a dust covering which conceals all but the mandibles.  These are used in placing the particles of dust or sand on the back, and each mandible can be moved independently of the other (Clausen 1940/62).  The pupa emerges from the cocoon by bursting it rather than by dissolving or cutting an opening.  There is one generation annually, and overwintering is as active larvae.


          Pseudoptynx sp. larvae do not have a covering of sand or debris, but rather conceal themselves in tree bark depressions (Gravely & Maulik 1911).  Here they are inconspicuous, their legs being hidden and their mandibles so widely separated that they lie along the sides of the head and thorax.  Larvae of Ascalaphus insimulans Wlk. assemble in linear groups on plant stems, with their bodies overlapping, so that only the heads and widespread mandibles are visible (Clausen 1940/62).


          Wheeler (1930) noted several species that rely on protective coloration rather than a soil covering.  One undermined species from Panama had a greenish-colored larva that inhabited the leaves of trees and lay with its body flattened along the mid-rib on the upper surface.  When awaiting prey, the mandibles were opened so widely that they were completely hidden beneath the lateral margins of the thorax.



References:   Please refer to  <biology.ref.htm>, [Additional references may be found at: MELVYL Library ]