taxonID	type	description	language	source
645AD891E989599FADBE40F2164C712B.taxon	diagnosis	Diagnosis. Paraptychoptera pollux sp. nov. is known only from a single male collected near a small overflow of the Mavrovo Lake with muddy shore invaded by rich vegetation (Fig. 6). The male general habitus and wing venation with spots are highly similar to P. helena and P. castor sp. nov., but the wing spots tend to be reduced, mostly the basal spot and distally band which is divided into two distinct patches. Further differences are in male epandrium: The less developed finger-like subapical process is unique to P. helena, P. castor sp. nov., and P. pollux sp. nov. (Figs 2 d, 4 e, 5 d). However, in P. pollux sp. nov., this process is much shorter than in P. castor, but comparably longer than in P. helena, with blunt apex and divergent from the basal thorn. However, there is an important difference in the basal thorn orientation. In P. pollux, the basal thorn is oriented upward, while in P. helena the thorn is curved downward. Hypopygium shape with its rounded and slightly inflated apex is the second most distinctive character of P. pollux sp. nov., which differentiates it from both P. castor and P. helena, as well as from other Paraptychoptera species (Figs 2 c, 4 d, 5 c). Paramere lateral arms of P. pollux are similar to P. castor sp. nov. and P. helena, but are shorter and gradually widened at tip and rounded (Fig. 5 h). The rest of the characters, such the gonocoxite and gonostylus complex, hypandrium and the aedeagus are highly similar to P. helena (Fig. 4 g, i). Figure 5. Ptychoptera pollux sp. nov. a flagellum of antennae b right wing c epandrium, dorsal d subapical lobe of epandrium, ventral e gonocoxite and gonostylus complex, dorsal f gonostylus anterior and medial lobules, caudal g hypandrium, caudal h paramere, ventral i aedeagal complex, dorsal. Figure 6. Habitat of Ptychoptera pollux sp. nov., north Macedonia, Novo Selo village, Mavrovo lake outflow.	en	Keresztes, Lujza, Kappert, Juergen, Henning, Maria, Toeroek, Edina (2021): Helen's twins in the Balkans: discovery of two new Paraptychoptera Tonnoir, 1919 species closely related to P. helena Peus, 1958, with systematic revision of the " lacustris " group (Diptera, Ptychopteridae). ZooKeys 1071: 63-81, DOI: http://dx.doi.org/10.3897/zookeys.1071.58598, URL: http://dx.doi.org/10.3897/zookeys.1071.58598
645AD891E989599FADBE40F2164C712B.taxon	etymology	Etymology. The specific epithet is named after Pollux, the twin brother of Castor in Greek mythology, known together as the Dioscuri, both twin brothers of Helena, because together with P. castor they share close morphological similarity with P. helena and all together they form a distinct monophyletic unit among Paraptychoptera, as was recovered by our cladistic analysis (Fig. 7). Figure 7. Single most parsimonious tree (1392 steps) based on 53 morphological characters. Bootstrap (B) values over 50 % are noted above the corresponding branches, respectively. Branch support was calculated by bootstrap with 10000 replicates. Character states are shown above branches.	en	Keresztes, Lujza, Kappert, Juergen, Henning, Maria, Toeroek, Edina (2021): Helen's twins in the Balkans: discovery of two new Paraptychoptera Tonnoir, 1919 species closely related to P. helena Peus, 1958, with systematic revision of the " lacustris " group (Diptera, Ptychopteridae). ZooKeys 1071: 63-81, DOI: http://dx.doi.org/10.3897/zookeys.1071.58598, URL: http://dx.doi.org/10.3897/zookeys.1071.58598
922FD119F93D561C898E8F20FE3A603D.taxon	diagnosis	Diagnosis. Ptychoptera (Paraptychoptera) castor sp. nov. is known only from a single male collected near a limnocrene karst spring with muddy shore invaded by rich vegetation at Repet y Izvorit, Tragjas, Albania (Fig. 3). Male general habitus, wing venation and spots are highly similar to P. helena (Fig. 4 a, b, c). However, the male epandrium has a unique design, differentiated from all other members of Paraptychoptera, but close to P. helena (Fig. 4 d, e). In contrast to P. helena, the finger-like subapical process on its ventral side is well developed, with a basal chitinous process, equal in length with subapical lobe, which is much shorter in P. helena (Fig. 2 d) and the conspicuous long harpoon-shaped apex of the hypoproct (Fig. 2 c) which is bilobate in P. helena (Fig. 4 d). Gonostylus apical stylus is long, twice as long as the secondary lobe (Fig. 2 e), which differentiates it well from P. helena, where such a process is subequal. Gonostylus anterior lobule with a short finger-like vental process (Fig. 2 f), while in P. helena such a process is much longer and curved at tip (Fig. 4 g). Hypandrium apex lacking a narrow-lobe-like terminal division (Fig. 2 g) which is present in P. helena (Fig. 4 h), and well developed in all other Paraptychoptera species, in addition with a series of fine differences in male aedeagal complex and paramere (Fig. 2 h, i). Figure 2. Ptychoptera castor sp. nov. a flagellum of antennae b right wing c epandrium, dorsal d subapical lobe of epandrium, ventral e left gonocoxite with gonocoxite lobes f anterior and medial lobules, details g hypandrium, caudal h paramere, ventral i aedeagal complex, dorsal. Figure 3. Habitat of Ptychoptera castor sp. nov., south-western Albania, Tragjas, Repet y Izvorit. Figure 4. Ptychoptera helena, paratype male (ZFMK) a habitus male b head and thorax dorsal c right wing d epandrium, dorsal e subapical lobe of epandrium, ventral f gonocoxite and gonostylus complex, dorsal g gonostylus anterior and medial lobules, caudal h hypandrium, caudal i paramere, ventral j aedeagal complex, dorsal.	en	Keresztes, Lujza, Kappert, Juergen, Henning, Maria, Toeroek, Edina (2021): Helen's twins in the Balkans: discovery of two new Paraptychoptera Tonnoir, 1919 species closely related to P. helena Peus, 1958, with systematic revision of the " lacustris " group (Diptera, Ptychopteridae). ZooKeys 1071: 63-81, DOI: http://dx.doi.org/10.3897/zookeys.1071.58598, URL: http://dx.doi.org/10.3897/zookeys.1071.58598
922FD119F93D561C898E8F20FE3A603D.taxon	etymology	Etymology. The specific epithet is named after Castor, a god from Greek mythology, the twin brother of Helena, because of its close morphological similarity with P. helena.	en	Keresztes, Lujza, Kappert, Juergen, Henning, Maria, Toeroek, Edina (2021): Helen's twins in the Balkans: discovery of two new Paraptychoptera Tonnoir, 1919 species closely related to P. helena Peus, 1958, with systematic revision of the " lacustris " group (Diptera, Ptychopteridae). ZooKeys 1071: 63-81, DOI: http://dx.doi.org/10.3897/zookeys.1071.58598, URL: http://dx.doi.org/10.3897/zookeys.1071.58598
