Acostatrichia fluminensis ( Santos & Nessimian 2010 )

Santos, Allan Paulo Moreira, 2020, A review of the Neotropical microcaddisfly genus Acostatrichia Mosely, 1939 with description of a new species from Brazil (Trichoptera: Hydroptilidae: Leucotrichiinae), Zootaxa 4755 (2), pp. 201-230 : 205-208

publication ID 10.11646/zootaxa.4755.2.1

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Acostatrichia fluminensis ( Santos & Nessimian 2010 )


Acostatrichia fluminensis ( Santos & Nessimian 2010)

Figs. 3 View FIGURE 3 , 16 View FIGURE 16

Costatrichia fluminensis Santos & Nessimian 2010: 840 , figs. 9–19, male, female; type locality: Brazil, Rio de Janeiro, Mangaratiba, Reserva Ecológica Rio das Pedras, 22°59’29.4”S 44°06’02.6”W; type depository: DZRJ.

Santos et al. (2016), phylogenetic placement in Acostatrichia View in CoL .

Redescription. Length from front of head to tips of folded forewings 2.8–3.0 mm (n = 3). General color, in alcohol, brown. Head unmodified. Ocelli 3. Antenna 19-articulated; scape cylindrical, more than twice as long as wide, inner margin not produced; pedicel cylindrical; flagellomeres cylindrical, unmodified. Forewings each with costal vein simple, unmodified. Abdominal segment VII bearing two acute ventromesal processes, basal one shorter ( Figs. 3A, 3C View FIGURE 3 ).

Male genitalia. Segment VIII shorter dorsally than ventrally ( Fig. 3C View FIGURE 3 ); in ventral view, posterior margin of sternum very slightly emarginated ( Fig. 3A View FIGURE 3 ), without lateral processes; tergum with scattered setae. Segment IX mostly within segment VIII, ventrally open; with pair of elongate dorsolateral processes, converging apically in dorsal view ( Fig. 3B View FIGURE 3 ); downturned in lateral view ( Fig. 3C View FIGURE 3 ), each one with very long apical seta. Preanal processes each digitate and bearing very long seta ( Fig. 3C View FIGURE 3 ). Inferior appendages paired, short and triangular in ventral view, without apical or basal processes other than few setae ( Fig. 3A View FIGURE 3 ). Subgenital plate, in ventral view, broad, with pointed and moresclerotized apex ( Fig. 3A View FIGURE 3 ); in lateral view, triangular with pointed apex ( Fig. 3C View FIGURE 3 ). Tergum X membranous, bilobed, quadrangular in dorsal view ( Fig. 3B View FIGURE 3 ). Phallus tubular basally, bearing midlength complex with dorsal window and with basal loop indistinct; apical portion with spatulate sclerite ( Figs. 3D, 3E View FIGURE 3 ).

Material examined. HOLOTYPE male: Brazil, Rio de Janeiro, Mangaratiba , Reserva Ecológica Rio das Pedras, 22°59’29”S 44°06’03”W, 23.v.2009, J.L. Nessimian, light trap ( DZRJ) GoogleMaps ; PARATYPE: Brazil, Rio de Janeiro, Macaé, Córrego Duas Barras , 22°15’ 52°S 42°03’44”W, el. 217 m, 21.iii.2009, B.H.L. Sampaio, G.A. Jardim, I.C. Gonçalves, V. P. Alecrim, J.L. Nessimian, light trap, 1 male ( DZRJ). GoogleMaps

Additional material: Brazil, Paraná, Morretes, afl. do Rio Nhundiaquara , 25°25’04”S 48°54’05”W el. 91 m, 23.i.2011, A.P.M. Santos, D.M. Takiya, J.L. Nessimian, L.L. Dumas, light trap, 1 male ( DZRJ). GoogleMaps

Remarks. This species was originally described in Costatrichia , but other than the absence of a bulla in the costal vein of each forewing, it presents the features of the A. plaumanni Group, such as segment VII with a double ventromesal process ( Fig. 3A View FIGURE 3 ), a pair of long dorsolateral processes on segment IX ( Fig. 3C View FIGURE 3 ), and the inferior appendages short and not fused mesally ( Fig. 3A View FIGURE 3 ). The species has been transferred to Acostatrichia by Santos et al. (2016) based on phylogenetic studies, which indicated that both morphology and molecular data supported a close relationship between A. fluminensis and A. simulans ( Santos et al. 2016) . Santos & Nessimian (2010) also mentioned the absence of a subgenital plate in the original description, but the paratype and the additional specimen observed, which agree in all other aspects with the holotype, clearer present this structure. Acostatrichia fluminensis shares with A. plaumanni and A. simulans the similar general aspect of male genitalia, particularly the long and digitate pair of dorsolateral processes of segment IX, the presence of short preanal processes, each one with a long apical seta, and short and triangular inferior appendages. This species can be distinguished from these other two and from others in the A. plaumanni Group due to the dorsolateral processes of segment IX being strongly curved downward in lateral view ( Fig. 3C View FIGURE 3 ), and the phallus having an apical spatulated sclerite ( Fig. 3D View FIGURE 3 ).

Distribution. Brazil ( Fig. 16 View FIGURE 16 ).


Royal British Columbia Museum - Herbarium














Acostatrichia fluminensis ( Santos & Nessimian 2010 )

Santos, Allan Paulo Moreira 2020

Costatrichia fluminensis

Santos, A. P. M. & Nessimian, J. L. & Takiya, D. M. 2016: 205
Santos, A. P. M. & Nessimian, J. L. 2010: 840
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