Hydroptila nevdomek, Malicky & Ivanov & Melnitsky, 2020

Malicky, Hans, Ivanov, Vladimir D. & Melnitsky, Stanislav I., 2020, New Caddisflies (Insecta, Trichoptera) from the Krabi and Phang Nga Provinces southern Thailand, Zootaxa 4729 (3), pp. 401-415 : 406-407

Hydroptila nevdomek , new species ( Fig. 5 A–5D)

Holotype: male. Wings and body yellow brown. Length of each forewing 2 mm.

Male genitalia. Anterolateral margins of segment IX in lateral view acutely angulate 60°, this segment deeply incised in dorsal and ventral views. Segment X in lateral view long and abruptly narrowed, tapering posteriorly; in dorsal view trapezoidal, prominently narrowing in caudal part, with slightly convex lateral margins in basal 3/4. Inferior appendages in lateral view long, relatively wide and straight and parallel-sided proximally, wider and slightly curved upward in distal part; in ventral view divergent, thin and pointed, with small basal pieces separated by sutures. Subgenital plate slim, elongate, acute, and slightly bent. Phallus very long, with paramere at mid length forming 2 semispirals (proximal and distal, separated by rectilinear part) and directed ventrocaudad apically, and phallus with large apical tooth projecting dorsad at right angle.

Diagnosis. Simplified genital structures with lamellate inferior appendages, roof-like wide segment X with obtuse apex, well developed long paramere suggest this species to be related to the Hydroptila sparsa species complex. This species differs from numerous related similar species in the angled shape of the anterior margins of segment IX; in the distinctively clavate inferior appendages; in the large apical tooth of the phallus with a characteristically bent, long paramere extending to the middle of the terminal part of the phallus; and in the abruptly narrower configuration of segment X in dorsal view, without any species particularly similar to it in these characters.

Holotype: THAILAND, Krabi Province, 18 km N from Krabi, waterfall, 08º14’21”N, 98º55’17”E, height 320 m, UV light traps, 31 January 2014, leg. Melnitsky, Ivanov. (Locality 4)

Distribution. Thailand (known only from type locality).

Etymology. An indeclinable name with gender agreement irrelevant, from the Russian nevdomek (incomprehension).

Figures

FIGURE 5. Male genital structures of Hydroptila nevdomek new species: 5A, genitalia, left lateral; 5B, genitalia, dorsal; 5C, genitalia, ventral; 5D, phallus, left lateral.