Acostatrichia simulans Mosely, 1939

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 : 209-210

Acostatrichia simulans Mosely, 1939

Figs. 6 , 16

Acostatrichia simulans Mosely 1939: 229 , figs. 179–182, male; type locality: Brazil, Santa Catarina, Nova Teutonia; type depository: BMNH.

Angrisano (1995), reported from Uruguay.

Angrisano & Sganga (2010) , larva, pupa, case, biology, reported from Argentina.

Santos et al. (2016), phylogenetic placement.

Redescription. Length from front of head to tips of folded forewings 2.0–3.0 mm (n = 9). General color, in alcohol, light brown. Head unmodified. Ocelli 3. Antenna 19-articulated; scape cylindrical, twice as long as wide, inner margin not produced; pedicel cylindrical; flagellomeres cylindrical, unmodified. Forewings each with costal vein bearing short basal bulla. Abdominal segment VII bearing two acute ventromesal processes, basal one shorter ( Figs. 6A, 6C ).

Male genitalia. Segment VIII shorter dorsally than ventrally ( Fig. 6C ); in ventral view, posterior margin of sternum with shallow median V-shaped incision ( Fig. 6A ), without lateral processes; tergum with scattered setae. Segment IX mostly within segment VIII, ventrally open; with pair of elongate dorsolateral processes, gradually curved inwards in dorsal and ventral views ( Figs. 6A, 6B ), almost straight in lateral view ( Fig. 6C ), each one with sinuous subapical spine ( Figs. 6A, 6B, 6C ). Preanal processes digitate and each bearing very long seta ( Fig. 6C ). Inferior appendages paired, short and triangular in ventral view, without apical or basal processes ( Fig. 6A ). Subgenital plate, in ventral view broad and concave at apex ( Fig. 6A ); in lateral view, triangular ( Fig. 6C ). Tergum X membranous, posterior margin convex in dorsal view ( Fig. 6B ), slightly bilobed in lateral view ( Fig. 6C ). Phallus tubular basally, bearing midlength complex with dorsal window and basal loop shorter than basal portion of phallus; apical portion with Y-shaped sclerite and internal spine ( Figs. 6D, 6E ).

Material examined. Brazil, Santa Catarina, Nova Teutonia, ix.1963, F Plaumann leg., Flint 1975 det., 1 male ( NMNH); Nova Teutonia, i.1963, F. Plaumann, Flint det., 6 males ( NMNH). Argentina, Província Misiones, Salto Encantado Provincial Park, Arroyo Azul , 23-28.i.2008, Angrisano & Sganga leg., Sganga 2012 det., 1 male ( DZRJ). Uruguay, Artigas, Rio Cuareim, Sepulturas , 15.xii.1952, CS Carbonell , Flint det., 1 male ( NMNH).

Remarks. Acostatrichia simulans shows typical features of the A. plaumanni Species Group, such as the following: (1) a costal bulla in each forewing, (2) a double ventromesal process on segment VII, (3) the inferior appendages short and not fused to each other, and (4) a pair of long dorsolateral processes on segment IX. In the A. plaumanni Group, A. simulans shares more similarities in male genitalia with A. plaumanni and A. fluminensis , but it can be distinguished from those by a shallow median incision on the posterior margin of segment VIII in ventral view ( Fig. 6A ); and by the dorsolateral processes of segment IX curved inwards in ventral and dorsal views, each one with a short sinuous subapical spine ( Figs. 6A, 6B ). This is the only Acostatrichia species with immature stages described ( Angrisano & Sganga 2010). According to Angrisano & Sganga (2010), the larva is similar to those described for other Leucotrichiini genera, in particular to larvae of Zumatrichia Mosely 1937 , but the A. simulans larva differs by having the frontoclypeus with a reticulate sculpturing and each tarsal claw with an enlarged basal seta.

Distribution. Argentina, Brazil, and Uruguay ( Fig. 16 ).

Figures

FIGURE 6. Acostatrichia simulans Mosely 1939, non-type male from Santa Catarina, Brazil, genitalia. 6A, ventral; 6B, dorsal; 6C, left lateral; 6D, phallus, dorsal; 6E, phallus, left lateral. Scale bar = 0.1 mm.

FIGURE 16. Distribution map of the Acostatrichia species in South America, based on material examined here and previously published records. When latitude and longitude were not available, an approximate location was used. Circle, species in the Acostatrichia plaumanni Group; square, species in the Acostatrichia brevipenis Group; triangle, species in the Acostatrichia cerna Group.