Dipseudopsis robustior andamanensis Weaver & Malicky 1994

Pandher, Manpreet Singh, Kaur, Simarjit, Garima, Deepti & Dubey, Anil Kumar, 2021, New records of Caddisflies (Insecta: Trichoptera) from India, Zootaxa 5072 (5), pp. 463-477 : 464

Dipseudopsis robustior andamanensis Weaver & Malicky 1994

Dipseudopsis robustior andamanensis Weaver & Malicky 1994 , 134, fig. 47.

While identifying species of the genus Dipseudopsis , the precise orientation of the modified hind tibial spur is crucial because slight rotations of a tibia produce different perspectives of the spur ( Weaver & Malicky 1994; Oláh & Johanson 2010c). Furthermore, the male genitalia are rather simple, often lacking conspicuous characters ( Oláh & Johanson 2010c).

According to Weaver and Malicky (1994), “ D. robustior robustior Ulmer 1929 is the most common species of genus Dipseudopsis in Thailand and is somewhat difficult to distinguish from D. collaris and D. infuscata . Possibly these species are merely variants of a widely distributed species.” All three of these species are widespread in Southeast Asia: D. r. robustior has been reported from Cambodia, Indonesia (Sumatra), Peninsular Malaysia, Myanmar, Thailand, and Vietnam; D. collaris from China ( Hong Kong, Guangdong, Jiangsu, Jiangxi, Zhejiang), Japan (Hongshu, Kyushu), and the Philippines; and D. infuscata from China (Yunnan) and Indonesia (Java, Kalimantan, Sulawesi, and Sumatra). On each hind tibia of D. robustior robustior the apical points of the modified spur are unequal: one has a long slender curved point and the other has a short broad point. In D. collaris the points are shorter and subequal, only 1/3 as long as the base. In D. infuscata , “the two apical points of the modified spur [have] the longer point straight and slightly shorter than the unmodified base of the spur, and the shorter point curved with its apex directed mesad” ( Weaver & Malicky 1994).

Dipseudopsis robustior andamanensis Weaver & Malicky 1994 differs from D. r. robustior in that each hind tibia has a pincer-like modified hind tibial spur with two subequal points. The more recently described species Dipseudopsis cocon Oláh & Johanson 2010c (from Vietnam) is very similar to D. robustior andamensis , as both of these species have subequal crescent-shaped, pincer-like points of the modified hind tibial spurs. In their diagnosis for D. cocon, Oláh and Johanson (2010c) did not mention D. robustior andamanensis . Malicky (2013) suggested that D. cocon may be a synonym of D. robustior andamanensis . The only difference appears in the ratio of the length of the undivided base of a modified hind tibial spur to that of its two apical branches: The ratio is 0.5 for D. cocon and 1.6 for D. robustior andamanensis .

This difference may or may not be diagnostic for these two species-group taxa and D. robustior andamanensis may or may not be a distinct species rather than a subspecies of D. robustior . Resolution of these questions and questions about the status of D. collaris and D. infuscata will depend on morphological and molecular comparisons of multiple specimens of each of these purported taxa from Southeast Asia. For now, the conservative choice is to maintain the current situation, listing D. robustior andamanensis as an endemic subspecies on South Andaman Island.