Neosilba spiculata  

Diagnosis: Neosilba spiculata could be recognized by
the constant diameter of the aedeagus, this one with
4 longitudinal lines of spiculae from the base until
4/5 of the ventral surface (Figs. 7E, F); apex of the
aedeagus strongly S‑shaped in lateral view and slightly
wider in ventral view. Epandrium 2 or more times
longer than wide and parallel-sided. The new species
is similar to male terminalia of N. pendula, N. pseudopendula,
N. pantanense, N. perezi, N. cornuphallus,
N. turgidiphallus and the next new species N. angusta;
the male genitalia of N. spiculata is similar to species
of the nigrocaerulea subgroup. N. pendula differs the
apex of the filament 2‑3 times wider and the parameres
are tongue-like shaped in ventral view; N. pseudopendula
differs by it having the surstylus with a
distal lobe towards the apex and rounded parameres
(Figs. 7I, J); N. pantanense differs by having the spiculae
of the filament of the aedeagus located at the apical
third; N. perezi differs by its filament apex being
slightly S‑like shaped and having a smooth filament
of the aedeagus; N. angusta differs by having a narrowed
apex of the aedeagus. Species from the nigrocaerulea subgroup differs by its straight filament; N. cornuphallus
and N. turgidiphallus differ by the filament
of the aedeagus with different widths (i.e., wider at
the middle), without spiculae.