Description of the larval stages of the desert dragonfly Paragomphus sinaiticus (Morton), with notes on the larval habitat, and a comparison with three related species (Anisoptera: Gomphidae)

From a sample taken at Aguelman Timia (Niger) in 1980, 103 larvae pertaining to this sp., the only gomphid known from that area, were extracted. The ultimate instar and the 5 preceding instars were distinguished biometrically and morphologically. A detailed description of the ultimate instar, including scanning E M. micrographs, is presented. By a morphological comparison with P. cognatus (Ramb,, 1842), P. genei (Sel., 1841) and P. lineatus (Sel., 1850). it is shown that the structure of the prementum and of the last antennal segment are highly diagnostic. It appears that P. sinaiticus is more closely related to P. genei than to other spp. Some remarks on the larval habitat are also provided.