Hydraena trinidensis

Perkins, Philip D., 2011, New records and description of fifty-four new species of aquatic beetles in the genus Hydraena Kugelann from South America (Coleoptera: Hydraenidae), Zootaxa 3074, pp. 1-198 : 42

Trinidensis Complex

Perkins 1980: 180.

Six species comprise the Trinidensis Complex: H. trinidensis , H. tucumanica , H. beniensis , H. dariensis , H. browni , and H. quechua . These are very small to small species (ca. 1.11–1.40 mm), which have the pronotum with a more or less distinct piceous macula that is surrounded by testaceous color. The species are very similar in dorsal habitus and ventral characters; reliable identifications will require examination of the male genitalia.

In this complex the aedeagus is quite simplified: the main piece is not strongly arcuate and comparatively simple at the distal tip, the distal piece has ca. 3 simple lobes, and the parameres originate on the dorsal face of the main piece, usually near one another. Members of this complex are known from Argentina, Brazil, Bolivia, Colombia, Ecuador, Paraguay, Trinidad and Tobago, and Venezuela .