Chimarra ( Chimarra ) buenaventura, Holzenthal & Blanhik & Ríos-Touma, 2025

Holzenthal, Ralph W., Blanhik, Roger J. & Ríos-Touma, Blanca, 2025, New Philopotamidae (Insecta, Trichoptera) from Ecuador: seven new species and updated country checklist, ZooKeys 1263, pp. 123-145 : 123-145

Chimarra ( Chimarra) buenaventura sp. nov.

Fig. 3

Type material.

Holotype male: Ecuador: • El Oro: Reserva Buenaventura, small stream near Umbrellabird Lodge , 3.65367°S, 79.76829°W, el. 530 m, 11.x.2023, Ríos-Touma ( UMSP 000551868 ) ( UMSP) . Paratypes: same as holotype, 2 females ( MECN); 1 female ( UMSP) .

Diagnosis.

Chimarra buenaventura is a particularly distinctive species in the form of its tergum X, with very short and strongly sclerotized lateral lobes, terminating in a distinctive short, narrow projecting sclerite, and with the two sensilla of the lobe located on a recurved process near its distal margin. The phallotremal sclerite of various species in the group is often associated with a textured sclerotized “ curl, ” modified into a row of short spines in some species. In Chimarra buenaventura this structure seems to be modified into a distinct short, curved spine, buttressed basally by a sclerotized projection, appearing as a second short, branched tine. Females of many of the species have been illustrated. The female of C. buenaventura is distinguished by a pair of distinctively formed cup-shaped sclerites at the apicoventral attachment site of the vaginal apparatus, and by sinuate, paired sclerites on its ventral surface, which extend anterolaterally to the anterior cup-like sclerite, a generalized feature of the vaginal apparatus in Chimarra .

Description.

Adult. Forewing length male 5.0 mm, female 5.0– 5.25 mm ( n = 3). Color pale fuscous, partially denuded (specimens in alcohol). Male. Abdominal segment IX, in lateral view, with very pronounced sinuous extension of anteroventral margin and short apodemes from anterodorsal margin; posteroventral process elongate, posteriorly projecting, subacute apically. Tergum X membranous mesally, with short, sclerotized lateral lobes; in lateral view, each more or less parallel-sided, subtruncate apically, with very narrow, acute, apical projection, projection laterally recurved, continuous with membranous dorsal extension of lateral lobe; sensilla of each lobe two, on reflexed sclerotized curl, near apex of sclerotized lateral lobe. Preanal appendage short, rounded, in lateral view, wider than long. Inferior appendage, in lateral view, with ventral margin broadly rounded; bearing minute triangular cusp on mesal margin, in ventral or caudal view; dorsal thumb-like process of inferior appendage, in lateral view, projecting posteriorly, strongly mesally curved, with apex expanded and rounded. Phallus with ventral margin of phallobase distinctly projecting; phallic spines two, asymmetrically arrayed, anterior spine elongate, straight, posterior spine shorter, slightly curved; endotheca textured with small spines and also possessing short, curved spine, with basal tine-like projection; phallotremal sclerite complex composed of elongate rod and ring structure and membranous structure with pair of associated wishbone-like sclerites apically; endotheca not expanded in specimen examined, but phallotremal sclerite complex apparently associated with short, curved endothecal spine.

Female. Ventral sclerites of sternum IX with prominent membranous lateral pouches (“ clasper receptacles ” of Blahnik 1998). Vaginal apparatus moderately elongate, largely membranous, with pair of distinctly cupped sclerites posteroventrally (attachment or anchoring site of vaginal apparatus), posterodorsal sclerites absent; at midlength, with rounded, membranous lateral projections, ventral surface with paired sclerites, narrow and sinuous, extending from membranous lateral projections to anterior cup-like sclerite, flanking lateral margin of vaginal apparatus anteriorly.

Etymology.

Named after Reserva Buenaventura of Fundación Jocotoco, located in the southwestern foothills of the Andes and contains elements of the Tumbesian dry forests of southern Ecuador and the Chocó humid forests of northwestern Ecuador. In addition to rare and endemic birds and plants, it is the type locality of this new species.

Remarks.

Chimarra buenaventura is a new species in the ortiziana group, as defined by Blahnik (1998). Additional species were subsequently described by Blahnik and Holzenthal (2012) and Holzenthal et al. (2022). The group currently contains fifteen species, distributed from Mexico to the northern parts of South America, with one species extending to southeastern Brazil. This new species adds a sixteenth species. Species of the group have a characteristically formed inferior appendage, with a relatively short and mesally curved, thumb-like, dorsal projection, usually somewhat dilated and rounded apically. The various species are most readily distinguished by the form and shape of the lateral lobes of tergum X, and the position and disposition of its two sensilla.

Figures

Figure 3. Chimarra (Chimarra) buenaventura new species. Male genitalia A segments IX, X, lateral B segments IX, X, dorsal C inferior appendage, ventral D inferior appendages, oblique lateral E phallus, lateral (insets: phallic spine, phallotremal sclerite) F female genitalia, vaginal apparatus, ventral.