Bibrax amasanga, Tapuy-Avilés & Díaz-Guevara & Caterino, 2025

Bibrax amasanga sp. nov.

Figs 5 G, H View Figure 5 , 7 E – H View Figure 7 , 8 I View Figure 8

Type material.

Holotype • ♂ ( QCAZ -I-278673 ): “ Ecuador. Orellana, Estación Científica Yasuní PUCE, 496 m, -0.68315, -76.40004, 12 - 2016. Winkler, Brian Four ” / “ Caterino DNA voucher, Ext. MSC-13224, Morphosp. 278673 ” / “ QCAZ -278673 ” GoogleMaps . Paratype • 1 ♂: “ Ecuador F. co Orellana, Chiruisla Km 0 , 2, 218 m, 00°36'50"S, 75°52'34"W, 08-13DEC2005, J. Vieira ” / “ Ex: Winkler trap, Primary forest ” ( QCAZ -I-280398 ) GoogleMaps .

Diagnosis.

BL = 2.09 mm (n = 1). Body densely setose and brown, finely punctate above; head rounded at base, vertexal foveae impressed, without vertexal horns or tubercles at base; frons narrowing and rising to common antennal base; eyes reduced, with two or three ommatidia; gular teeth well-developed; antennae with scape very long, slightly sinuate at base, antennomere II (pedicel) slightly longer than III – VI combined, globose, narrow at base, widening towards apex, convex along outer margin, slightly concave on inner, protruding slightly at apical internal corner, III – VIII all bead-like, V and VII slightly larger and bearing elongate setae, IX – XI forming loose club, IX and X bearing elongate setae, XI densely setose; pronotum slightly longer than wide, widest near front, sides rounded; pronotal disk with lateral and median subbasal foveae; disk with strongly marked lateral longitudinal impressions; elytra rather short (wingless), humeri evenly sloped, sides rounded, each elytron with sutural and lateral dorsobasal foveae, lateral fovea with strong impression running posterad ~ 2 / 3 elytron length; posterior margin of elytron with outer submarginal tooth; subhumeral fovea absent; dorsal surface of abdomen distinctly punctate; protibia swollen; junction of mesepimeron and metaventrite deeply foveate; metatrochanter with inner margin slightly expanded, with blunt tooth at inner corner; penultimate ventrite distinctly depressed at middle, swollen at sides, last abdominal ventrite bearing small median apical marginal flange. Aedeagus (Fig. 5 G, H View Figure 5 ) with rather reduced basal bulb, slightly rounded dorsally, with oval dorsobasal diaphragm; basal apodemes forming wide elongate plate; tegmen not obviously articulated with basal bulb, dorsally subdivided into two asymmetric processes, one shorter, thinner strongly arched, the other longer, wider, curved ventrally to acute apex; additionally, below tegmen, two thin, curved, spine-like processes, project apically and basally from midpoint of tegmen, distal process flattened at base.

Distribution.

This species is known only from the Yasuní Biological Station in Amazonian Ecuador.

Remarks.

This species and the next are extremely similar in external morphology, and, coming from the same locality, were not initially considered to be distinct species. Both are also similar to the preceding species from the Rio Anzu area, ca 200 km west (and 1000 m higher in elevation). While the male genitalia separate these species clearly, distinguishing the two Yasuní species from each other based on external morphology is challenging (particularly given that both are known only from single males). In both, males have antennomere II asymmetrically swollen and the male metatrochanter apically dentate. In this species the penultimate male abdominal ventrite appears slightly lengthened and more distinctly depressed than in the following. The shape of the swollen second antennomere also differs slightly, being more distinctly swollen along the outer margin in this species, and less flanged at the inner apex. Also, the male metatrochanters are distinct, with that of B. amasanga basally toothed, that of B. yasuni markedly prolonged at the apex.

We have two female Bibrax specimens from Yasuní that appear to be distinct from each other. One of them was collected in the same sample as this species: the two individuals differ considerably in size, with a smaller one comparable in size to both B. amasanga and B. yasuni (described below). The second female specimen is significantly larger and differs in depth and length of the elytral impressions, as well as in minor details of antennomere lengths. At present it is impossible to associate either of these with either of the described species from this site: it is possible that the larger specimen represents yet a third species from the site. More material and possibly DNA sequences will be necessary to make definitive associations.

Etymology.

This species’ name refers to a mythical ‘ spirit of the jungle’, Amasanga, who came to the people in dreams and taught them to hunt