Cardiasilus aysu Soares, Camargo & Lamas, 2025, sp. nov.
Creators: name: Soares, Matheus M. M.
name: Camargo, Alexssandro
name: Lamas, Carlos J. E.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Asilidae
Cardiasilus
Cardiasilus aysu

description: Cardiasilus aysu sp. nov.
Figs 2, 3, 4, 5, 19
Diagnosis
(males). The new species can be easily distinguished from the congenerics by the yellow postalar macrosetae (Fig. 2 B, C), inner dorsal margin of epandrium weakly excavated, and lacking processes (Fig. 3 A, F, H) and subepandrial sclerite somewhat diamond-shaped near its middle (Fig. 4 D).
Description.
Male holotype (Fig. 2 A). Body Length 12.3 mm; wing length 6.8 mm. Head (Fig. 2 A – F). Scape and pedicel orange-yellow, slightly darker at apex; postpedicel dark brown, lanceolate; stylus dark brown, bare, first element very short, second element long and abruptly narrowed at apex. Face golden pruinose, except gibbosity with mixed silvery and golden pruinosity; mystax with few upper slender black macrosetae and strong golden macrosetae below, extending along oral margin. Frons, golden pruinose, with long black orbital macrosetae. Ocellar tubercle dark brown, with one to two pairs of proclinate long and slender ocellar macrosetae; vertex golden pruinose, almost bare of major setae, only with few slender black setae posteriorly; upper-most four to five postocular macrosetae black, remaining macrosetae yellowish-white. Postcranium golden pruinose, with long, slender, and dense white lower occipital setae. Palpus dark brown, with few short white setae. Proboscis black, ventral surface with long white setae, apex with short white setae. Thorax (Fig. 2 A – C). Antepronotum with few strong golden macrosetae, covered with golden pruinosity and sparse short and white setae. Scutum wholly covered with short vestiture of black setae and golden pruinosity, except notopleural, supra-alar, and acrostichal area close to scutellum with short white setae, in anterior view with U-shaped dark brown median stripe along acrostichal area, followed by L-shaped dark brown paramedian stripe along dorsocentral and intra-alar areas, with both stripes extending slightly beyond transverse suture. Three to four pairs of black, postsutural dorsocentral macrosetae, two black notopleural macrosetae, one black supra-alar macroseta, two yellow postalar macrosetae (anterior one shorter). Scutellum with one pair of apical pale yellow macrosetae, dorsal surface covered with short white setae. Pleuron mostly silvery pruinose, except anepisternum and katepisternum with golden pruinosity anteriorly, anepisternum, katepisternum, anepimeron and meron with few long white setae posteriorly, katatergite with vertical row of yellow macrosetae. Legs (Fig. 2 A). Mostly yellow, except all coxae with dense silvery pruinosity, all femora dorsally with short black setae, apex of mid and hind femora dorsally, apex of all tibiae, apex of all tarsomeres one to four and all tarsomeres five dark brown. Legs with white or golden macrosetae, except when as noted. Leg I. Coxa with long and dense white macrosetae anteriorly. Femur with one posterior black macroseta at middle, ventral surface with long setae at basal 1 / 2. Tibia with one anterodorsal black macroseta at basal 1 / 4, three dorsal black macrosetae, one near middle and two at apical 1 / 2, one antero, one dorsal, one posterodorsal, and one ventral black macrosetae at apex, two anterior long macrosetae at apex (~ 2 × longer than remaining apical macrosetae), posterior row of four long macrosetae from basal 1 / 4 to apex, three ventral long black setae near middle. Basitarsus with one antero and one posteroventral short black macrosetae at apex, one posteroventral long macroseta near base, tarsomeres one to three with crown of long macrosetae at apex: one antero and one posteroventral, one antero and one posterodorsal. Leg II. Coxa with long and slender macrosetae at apical 1 / 2, some of them reaching lateral surface. Ventral surface of femur with short vestiture of white setae and five to six long ventral macrosetae at basal 1 / 2, one anterodorsal apical short black macroseta, one posterodorsal preapical short macroseta, anterior row of four macrosetae from base to apex, anteroventral row of short intermixed black and white macrosetae. Tibia with two to three short dorsal black macrosetae at apical 1 / 2, one ventral long black macroseta at middle, ventral row of short and slender black setae from basal 2 / 4 to apex, one posterior long and slender black seta at basal 1 / 3, two ventral strong macrosetae, one black at middle and one white preapical, one posterior strong macroseta at apical 1 / 3, crown of long intermixed black and white macrosetae at apex: one antero and one posteroventral, one antero and one posterodorsal, one anterior and one posterior. Tarsus with chaetotaxy similar to fore tarsus. Leg III. Coxa laterally with two posterior macrosetae. Femur with two to three anterior macrosetae, anteroventral row of short macrosetae, posteroventral row of long and slender setae at basal 1 / 2, few long and slender posterodorsal setae near base, one anterodorsal black preapical macroseta, one dorsal preapical macroseta. Tibia with one antero and one posterodorsal short black macrosetae near base, two long anterodorsal black macrosetae: one near middle and one at apical 1 / 2, two long anteroventral black macrosetae at apical 1 / 2, crown of black macrosetae at apex: one antero and one posteroventral, one ventral, one anterior and one dorsal. Tarsus with chaetotaxy similar to fore and mid tarsus. Wing (Fig. 2 G). Hyaline, veins brown, orangish at base and Sc. Membrane with sparse dark brown microtrichia at apex of cells r 1, r 2 + 3, r 4 and bordering the veins R 4 and R 5. Halter: yellow. Abdomen (Fig. 2 A, B, H). Mostly brown, becoming orange from segments five to eight, densely covered with golden pruinosity, except lateral margins of tergites one to four, silvery pruinose. Posterior margin of tergite one with six to seven long black macrosetae, lateral margin with seven to eight white lateral marginal macrosetae, lateral margins of tergites two to six with two strong white lateral marginal macrosetae, tergites mostly clothed by short vestiture of black setae, becoming white laterally. Sternites one to four densely silvery pruinose, sternites five to eight mostly orange, with weak silvery pruinosity, sternites two to six with two to three pairs of pale yellow macrosetae mid-laterally and clothed with short, sparse, white setae. Terminalia (Figs 3, 4). Orange-brown. Tergite eight somewhat saddle-shaped, narrowing at middle of anterior and posterior margins, posterior 1 / 2 with two to three rows of short setae, longer at posterior corners (Fig. 3 D). Sternite eight with short and slender white setae at posterior 1 / 3, with long digitiform projection at middle of posterior margin, ~ 2 / 3 as long as sternite eight length, with conspicuous yellow setae (Fig. 3 E). Epandrium inflated laterally and posteriorly, resembling the ideogram of a heart in dorsal view, lacking inner and apical projections dorsally, inner ventral margin with a short preapical dentiform process, mostly with short vestiture of brownish setae, except apex with slightly longer yellowish setae (Fig. 3 A – C, F – I). Cercus short, digitiform, laterally compressed, covered with short setae (Fig. 3 A). Subepandrial sclerite long and narrowing towards apex, with a median subtriangular lateral process (somewhat diamond-shaped near its middle), almost at the same level, internally, with a pair of short, tooth-like processes directed anteriorly, and with a short dentiform preapical process, apex dorsoventrally flattened and covered with short setae (Fig. 4 D). Hypandrium subrectangular, with a short concavity at posterior margin, covered with short setae at posterior 1 / 2 (Fig. 4 E). Gonocoxite L-shaped, pointed at base and rounded at apex, with slightly preapical concavity at dorsal margin, few short setae at basal 2 / 3 of external surface (Fig. 4 A, B). Gonostylus ~ 1 / 2 as long as gonocoxite, somewhat digitiform, with ventral indentation at apical 1 / 3, apex rounded (Fig. 4 A, B). Ejaculatory apodeme fan-shaped (Fig. 4 C). Phallus long and thin, longer than length of hypandrium plus gonocoxite, divided into two prongs along the entire length (Fig. 4 C).
Female (Fig. 5). Similar to male, except as noted: Body length 13.5 mm; wing length 6.8 mm. Abdomen wholly brown, only the segment seven and the basal 1 / 2 of ovipositor sometimes orange, tergite seven with dark brown macrosetae posteriorly, sternite seven with white macrosetae laterally and posteriorly. Terminalia (Fig. 5 C – F). Laterally compressed from middle of tergite and sternite eight, long and slender, almost two times the length of tergite seven, covered with short black setae, longer before the opening of the genital fork, apex of sternite eight curved ventrally, weakly sclerotized, bare, and strongly striated. Tergite 9 + 10 slightly longer than cercus, mostly bare and shiny, only covered with few short and sparse white setae. Cercus short, digitiform, covered with short and slender white setae. Hypoproct short, V-shaped. Two sclerotized and rugose spermathecae present, membranous at base.
Type examined material.
Holotype: • ♂ (MZUSP) labelled: “ Brasil: MS [state of Mato Grosso do Sul]: Porto Murtinho | Trilha Fazenda Campo Florido | 21°41'52,0"S, 57°45'57,1"W | Ativa | 11.xii.2013 | Lamas & eq. cols. | SISBIOTA | CNPq / FAPESP ” “ HOLOTYPE | Cardiasilus aysu | Soares, Camargo & Lamas [red label] ”. Holotype condition: Good, not dissected. Paratypes: • same data as holotype (2 ♂, one dissected, MZUSP); same data, except: 21°38'15,07"S, 57°42'10,2"W | Coleta manual (rede) | 12.xii.2011 | Lamas, Nihei & eq. col. (1 ♂, MZUSP); same data, except: Fazenda Retiro Conceição – Trilha | da Espinhadeira | 21°40'59,7"S, 57°46'42,5"W | Malaise 31 | 10–25.i.2012 | Lamas, Nihei & eq. col. (2 ♂, MZUSP); same data, except: 21°41'06.2"S, 57°46'35.7"W | coleta manual (rede) | 11.xii.2011 (1 ♂, MZUSP; 2 ♂, NHMW); • Porto Murtinho (norte) | Estrada para Pirizal, km 18 | 21°33'05"S, 57°45'35"W | 19–31.i.2008 | Nihei, S.; Figueiredo, R. & Almeida, J. (col.) (2 ♂, MZUSP; 2 ♂, NHMW); • same data, except: 21–30.i.2008 (2 ♂, one dissected, MZUSP); same data, except: 24.i.2008 | F. A. Esteves col. (1 ♂, MZUSP); • same data, except: Faz. São Fernando, km 12 | 21°36'30"S, 57°49'02"W | 19–31.i.2008 | Nihei, S.; Figueiredo, R. & Almeida, J. | (col.) (1 ♂, MZUSP); same data, except: Arredores do Hotel dos Camalotes | 21°42'28"S, 57°35'00"W | 21–30.i.2008 (1 ♂, MZUSP).
Additional examined material.
Brazil, MS [state of Mato Grosso do Sul]: Porto Murtinho (norte), Estrada para Pirizal, km 18, 21°33'05"S, 57°45'35"W, 19–31.i.2008, Nihei, S.; • Figueiredo, R. & Almeida, J. (col.) (2 ♀, MZUSP; 2 ♀, NHMW); same data, except: Trilha Fazenda Campo Florido, 21°41'52,0"S, 57°45'57,1"W, Ativa, 11.xii.2013, Lamas & eq. cols. (4 ♀, two dissected, MZUSP).
Remarks.
The new species is easily recognized by the characters presented in the key and diagnosis (see above).
Distribution.
Brazil (state of Mato Grosso do Sul) (Fig. 19).
Etymology.
From the Tupi-guarani aysú = love, referring to the male terminalia, which resembles an ideogram of a heart in dorsal view. The species’ name is treated as a noun in apposition.
description: Published as part of Soares, Matheus M. M., Camargo, Alexssandro & Lamas, Carlos J. E., 2025, A taxonomic synopsis and identification key to the genera of the Myaptex group (Diptera, Asilidae, Asilinae), with description of a remarkable new genus and three new species from the South American Chaco, pp. 311-341 in ZooKeys 1232 on pages 311-341, DOI: 10.3897/zookeys.1232.142494