Thereus Hübner, 1819

Faynel, Christophe & Fåhraeus, Christer, 2023, Two new Thereus species from Peru, with notes on ecological niche partitioning (Lepidoptera: Lycaenidae: Theclinae), Zootaxa 5315 (4), pp. 301-314 : 303

Thereus Hübner

Type species: Papilio lausus Cramer

Thereus is estimated to contain 35 species, including 11 that are undescribed ( Robbins et al. 2015). The genus is characterized externally by: (1) a sexually dimorphic number of antennal nudum segments ( Robbins 1991), and genitally by: (2) sclerotized elements on the membrane in between the papillae anales in female on all species except two ( Robbins 1991); and (3) two pairs of brush organs on the vinculum of the male genitalia ( Robbins 1991, Robbins et al. 2015), exceptionally reduced to the only dorsal pair. Male DFW androconia vary from absent to a scent pad distal of the discal cell, or with both scent pad and scent patch at the same location. Morphologically, the new species belongs to the Thereus eryssus species group, which also includes T. eryssus , T. columbicola and T. illex . This group is overall similar and composed of larger species with chocolate brown ventral side and single or double DFW androconia. They are phenetically close to the Thereus ismarus species group, consisting of larger species with more white “lines” on the underside, and to the Thereus genena species group, which is composed of smaller species with less dark brown VW coloration, smaller single or double DFW androconia, and a VHW postmedian band closer to the distal margin.