Nannochoristidae

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Nannochoristidae
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Mecoptera
Family: Nannochoristidae
Tillyard, 1917
Genera

Nannochorista
Microchorista

Nannochoristidae is a primitive family of scorpionflies that have many unusual traits. It is a tiny, relict family of about eight species, with members of the genus Nannochorista occurring in New Zealand, southeastern Australia, Tasmania, and Chile and thus probably of Gondwanan origin. The adults look like scorpionflies with more pointed elongate wings. Most mecopteran larvae are eruciform, or shaped like caterpillars. Nannochoristid larvae, however, are elateriform, or shaped like a wireworm or click beetle larva. They are also the only entirely aquatic Mecoptera. Wing venation suggests a close relationship to dipterans.

They are predatory, primarily on the larvae of aquatic Diptera. They are locally common; there is a story of a researcher in New Zealand who got his nannochoristid specimens from his back yard.

Some research suggests that nannochoristids are the only holometabolous insects that have true larval compound eyes [1]. All other eyed larvae have stemmata, which are structurally different from adult compound eyes with ommatidia. This is unusual since most adult features are present as imaginal discs in larvae and not formed until pupation. The presence of compound eyes in nannochoristid larvae suggest that the timing of the development of adult features can be initiated earlier in development, which has startling implications for insect evolutionary development.

[edit] Species

This list is adapted from the World Checklist of extant Mecoptera species: Nannochoristidae and complete as of 1997.

  • Microchorista Byers, 1974
  • Microchorista philpotti (Tillyard), 1917 (New Zealand)
  • Nannochorista Tillyard, 1917
  • Nannochorista andina Byers, 1989 (Argentina, Chile)
  • Nannochorista dipteroides Tillyard, 1917 (Tasmania)
  • Nannochorista dipteroides eboraca Tillyard, 1917 (Australia)
  • Nannochorista edwardsi Kimmins, 1929 (Chile, Argentina)
  • Nannochorista holostigma Tillyard, 1917 (Tasmania)
  • Nannochorista maculipennis Tillyard, 1917 Tasmania)
  • Nannochorista neotropica Navás, 1928 (Chile, Argentina)


[edit] References

  1. ^ Melzer, R. R., H. F. Paulus, & N. P. Kristensen (1994). The larval eye of nannochoristid scorpionflies (Insecta, Mecoptera). Acta Zoologica 75: 201.