Isosticta robustior Ris, 1915

Grand, Daniel, Marinov, Milen, Jourdan, Herve, Cook, Carl, Rouys, Sophie, Mille, Christian & Theuerkauf, Jörn, 2019, Distribution, habitats, phenology and conservation of New Caledonian Odonata, Zootaxa 4640 (1), pp. 1-112 : 34-35

Isosticta robustior Ris, 1915

( Fig. 29 )

Isosticta robustior Ris, 1915: 66 . Distribution ( Fig. 30 ). Endemic to New Caledonia. This large species is recorded from more than 40 localities in the mountains of Grande Terre. Kimmins (1958) recorded it from Lifou but this island has no rivers so individuals must have dispersed from Grande Terre.

Habitat. This species occurs on creeks with rocky beds in hilly forest environments. It seems to avoid ultramafic soils, especially in the lowlands.

Biology and behaviour. Larvae were described by Lieftinck (1976). Adults remain around water, resting for long times on riverside vegetation. Oviposition takes place in tandem, the female inserting her eggs into diverse water plants as well as decomposing timber. Sometimes, eggs are laid 2 or 3 m above the water surface. DG observed a complete emergence on 14 th January 2010 above the creek on the road of “Le Sanatorium” on the east side of the Col de la Pirogue near Païta, between 07:15 h (larva coming to rest) and 11:45 h (first flight of the imago).

Status. Isosticta robustior is widespread on Grande Terre, with sometimes substantial populations, hence we rank it LC.

Figures

FIGURE 29. Isosticta robustior: a) male, b) female.

FIGURE 30. Records of Isosticta robustior.