Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 64, 1935
– 247 –


  • 1. A review of the literature on S. prasina (Newm.) is given together with its classification, systematics, and distribution.

  • 2. The bionomics of this insect is discussed. It is pointed out that for the most part the insect inhabits turbulent mountain torrents and requires water of extreme purity and high oxygen content. Its food, size, optimum, maximum, and minimum temperatures, its respiratory movements, locomotion, and reactions to light are discussed. Its enemies and known parasites are noted. An instrument for determining spot velocities in turbulent water is described.

  • 3. The detailed anatomy of the nymphal and imaginal instars is given and differences from the generalised insect-type indicated. Chief among these are the nymphal adaptations of the tibio-tarsal region of the legs correlated with its aquatic habitat; and the presence of a gas in the crop and gizzard of the imagines. Finally, in connexion with the venation, it is concluded that M5 is not present in Stone-flies.

  • 4. The venation of brachypterous males is described and shown to differ but little from the general condition; it is, however, more variable. The distal branching of Rs, M, and Cu show the greatest variation, and the cross-veins are greatly reduced in number.