Description of the Nymph of Tramea binotata (Rambur, 1842) (Odonata: Libellulidae)

摘要

The nymph of Tramea binotata (Rambur, 1842) is described and illustrated based on reared specimens from Brazil and Ecuador, and also matching nymphs from Venezuela. A new character was discovered, i.e., density of minute spiniform setae scattered on the dorsum of abdominal segments 7 & 8, that separates the Neotropical species into two groups: high density of the tiny setae separates T. binotata, T. insularis Hagen, 1861 and T. calverti Muttkowski, 1910 from the other known species which have zero to only a few of these setae. Tramea binotata is distinct from most other Neotropical species known in the nymph stage by having only 7 or 8 palpal setae, rarely 6 or 9, on one side (versus 10-12); T. calverti and T. insularis have similar low numbers of palpal setae (8-10) but each has more premental setae per side (11-14 in calverti and insularis vs. 8-10, rarely 11, in binotata). The nymphs of Tramea minuta De Marmels & Racenis, 1982 and T. rustica De Marmels & Racenis, 1982 are still unknown.