Alterosa orgaosensis, Blahnik Table Of Contents, 2005

Blahnik Table Of Contents, Roger J., 2005, Alterosa, a new caddisfly genus from Brazil (Trichoptera: Philopotamidae), Zootaxa 991 (1), pp. 1-60 : 41-42

publication ID 10.11646/zootaxa.991.1.1

persistent identifier

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scientific name

Alterosa orgaosensis

new species

Alterosa orgaosensis , new species

Fig. 20A–D View FIGURE 20

This species is very similar to A. guapimirim and, as discussed previously, it is possible that the two may eventually prove to be not specifically distinct. It resembles that species in having an inferior appendage with a very short 2nd article, tergum X with a large, inflated apex and a basolateral margin that is peculiarly cupped. Additionally, the apices of the preanal appendages of both species are unusual in being concavely cupped, each bearing a thick spine­like seta. The two species differ primarily in the structure of the intermediate appendage, which is apically rounded and setose in A. guapimirim and concave and armed much like the preanal appendage in A. orgaosensis . Another difference is that tergum X is more distinctly dome­shaped in A. orgaosensis .

Adult. Color overall, dark brown; legs, palps, and antennae slightly paler, wings irregularly mottled with small light brown spots. Male forewing 7.2–7.8 mm.; female 7.8–8.2 mm.

Male genitalia. Tergum VIII with posteromesal margin not or scarcely emarginate. Sternum IX with anterolateral margin forming a rounded projection in dorsal half; posteroventral margin moderately produced, forming broadly rounded expansion; tergum IX reduced, forming a mesal projection over base of tergum X, projection prominent, apex as viewed dorsally, rounded, subspatulate. Tergum X with weakly rounded lateral margin and greatly enlarged apex; apex sensillate, forming greatly enlarged expansion in apical half, rounded and distinctly enlarged in lateral view; tergum basolaterally with short, setose, apically­rounded projection. Intermediate appendage heavily sclerotized, moderately elongate, rod­like and mesally curved; apex with rounded preapical concavity, with 1 or 2 setae in concavity, setae sclerotized and spine­like. Preanal appendage similar in structure to, but slightly longer than, intermediate appendage, narrow, sinuous, with apex projecting outward, elongate, with scant setae on lateral margin; apex rounded, with distinct terminal seta in preapical concavity, seta stout and spine­like. Inferior appendages elongate, linear, flattened on mesal surface; 1st article, in lateral view, narrow, about 3 times longer than wide, tapering apically; 2nd article shorter than 1st, (less than half the length), nearly as wide as base as apex of 1st article, more or less uniform in width; apex rounded, with small pad of short, stiff apicomesal setae. Phallobase tubular, narrow, moderately elongate, strongly curved near middle; endotheca with about 8 large spines, basal pair very large and curved.

Holotype male: BRAZIL: Rio de Janeiro: Parque Nacional da Serra dos Orgãos, Rio Beija­flor , 22°27.063'S, 43°00.065'W, el 1125 m, 27.ii.2002, Holzenthal, Blahnik, Paprocki, Prather, ( UMSP000068474 View Materials ) ( MZUSP). GoogleMaps

Paratypes: BRASIL: Rio de Janeiro: — 2 females, same locality data as holotype ( MZUSP) ; — 5 males, 1 female, Rio de Janeiro, Parque Nacional da Serra dos Orgãos, Rio Paquequer , 22°922'S, 42°69.899'W, el 1000 m, 26.ii.2002, Holzenthal, Blahnik, Paprocki, Prather, ( UMSP) ( NMNH) .

Etymology. This species is named orgaosensis after the mountain range and park,

Parque Nacional da Serra dos Orgãos, where the type specimens were collected .


Museu de Zoologia da Universidade de Sao Paulo


University of Minnesota Insect Collection


Smithsonian Institution, National Museum of Natural History