Dixella moultoni, Corrêa & Scarpa & Pinho & Gil-Azevedo, 2024

Corrêa, Caio Cezar Dias, Scarpa, Priscila Luiza, Pinho, Luiz Carlos & Gil-Azevedo, Leonardo Henrique, 2024, Three New Species Of Dixella Dyar & Shannon (Diptera: Dixidae) From Santa Catarina, Brazil, Zootaxa 5433 (3), pp. 321-338 : 322-327

Dixella moultoni sp. nov.

( Figs. 1–4 )

Type Material. HOLOTYPE: ♂ (slide)—[ MNRJ41421 ] BRAZIL, Santa Catarina, Bom Retiro, Reserva Particular do Patrimônio Natural Grande Floresta das Araucárias, Riacho 1, S27°55’19” W49°26’29”, 19/XI/2017, LC Pinho col. ( MNRJ) . PARATYPES: 1♂ 2♀ (slide)—[ MNRJ41418—41420 ] same data as holotype ( MZSP) ; 14♂ 5♀ (96% ethanol)—[ MNRJ41103 ] same data as holotype ( MNRJ) ; 3♀ 2P 1L (slide)—[ MNRJ40912–40914 ] Brasil, Santa Catarina, Bom Retiro, Riacho Paredão , S27°53’48” W49°26’14”, 05/XI/2016, LC Pinho col. ( MNRJ) ; 1♀ 1P 1L (slide)—[ MNRJ40922 ] Brasil, Santa Catarina, Bom Retiro , RPPN Grande Floresta das Araucárias, Riacho Alojamento , S27°53’49” W49°26’24”, 05/XI/2016, Hand net, LC Pinho col. ( MNRJ) ; 1♂ 1P 1L (microscope slide)—[ MNRJ40921 ] same data as previous, except: 04/XI/2016 ( MNRJ) ; 4♂ 2♀ (96% ethanol)—[ MNRJ41100 ] Brasil, Santa Catarina, Bom Retiro , RPPN Grande Floresta das Araucárias , S27°54’01” W49°26’19”, 18/XI/2017, LC Pinho et al. col. ( CE-MHS) .

Additional material examined. BRAZIL, Santa Catarina: Grão Pará: 14♂ 13♀, Parque Estadual da Serra Furada , S28°09’07” W49°23’18”, 16/XI/2012 – 08/I/2013, Malaise, LC Pinho, MC Novaes & MF Haddad col. ; 2♂, 6♀, Parque Estadual da Serra Furada , CAPEA stream, S28°09’07” W49°23’30”, 16/XI/2012 – 07/I/2013, Malaise, LC Pinho, MC Novaes & MF Haddad col. ; 1♂, 1♀, Parque Estadual da Serra Furada , S28°09’07” W49°23’18”, 08/I–16/II/2013, Malaise, LC Pinho, AL Schlindwein, AP Amaral & MO Bessell col. ; 5♂, 2♀, Cachoeira do Amado , S28°08’57” W49°21’17”, 16/XI/2012 – 08/I/2013, Malaise, LC Pinho, MC Novaes & MF Haddad col. ; 2♂, Parque Estadual da Serra Furada, Rio Braço Esquerdo , S28°09’01” W49°21’21”, 16/XI/2012, Light trap, LC Pinho, LS Gomes & AL Schlindwein col. ; 2♂, 3♀, Parque Estadual da Serra Furada , CAPEA stream, S28°11’26” W49°23’30”, 15/X–16/XI/2012, Malaise, LC Pinho, AL Schlindwein & LS Gomes col. ; 2♂, 1♀, Parque Estadual da Serra Furada , CAPEA stream, S28°11’23” W49°23’32”, 08/I–16/II/2013, Malaise, LC Pinho, AL Schlindwein, AP Amaral & MO Bessell col. ; 1♀, Parque Estadual da Serra Furada , CAPEA stream, S28°11’26” W49°23’30”, 06/ IX–15/X/2012, Malaise, LC Pinho, AC Ganzer, LS Gomes & AG Parise col. ; 1♂, Cachoeira do Amado , S28°08’57” W49°21’17”, 08/I–16/II/2013, Malaise, LC Pinho, AL Schlindwein, AP Amaral & MO Bessell col. Orleans: 1♂, Rio Minador , S28°10’28” W49°24’36”, 12/X–10/XI/2013, Malaise, LC Pinho col. ; 4♀, Rio Minador , S28°10’28” W49°24’36”, 06/VII–19/VIII/2013, Malaise, LC Pinho col. Urubici: 1♂, Parque Nacional de São Joaquim, Morro da Igreja , 07/III–25/ V /2005, Malaise, LC Pinho & LEM Bizzo col. ; 4♂, Cascata Avencal , S28°02’48” W49°37’01”, 02/XI/2018, LC Pinho & CCD Corrêa col.

Diagnosis. Adults with body pattern color brown ( Fig. 1 ). Male with gonostylus cylindrical with truncate apex ( Fig. 3A–E ). Female with sternite IX undivided piece with two projections in the medial portion ( Fig. 4B ).

Description. Male. Body length: 3.1 mm (n = 8) ( Fig. 1A ) Head ( Fig. 2B ) uniformly brown with row of setae on dorsolateral portion, and setae around the eyes in the posterior portion. Antenna setose and 0.55x length of the wing. Scape brown and collar-like. Pedicel brown, globose, and 0.4x length of flagellomere I. Flagellum light brown with 14 flagellomeres. Flagellomere I cylindrical, 1.9x length of flagellomere II. Flagellomere II smaller than flagellomere III. Flagellomeres III to XIV decreasing in length. Flagellomere XIV with a pair of divergent apical setae. Clypeus brown, quadrate, and ca. 10 setae in the medial portion. Maxillary palpus brown and 5-segmented; maxillary palp V claviform. Maxillary palpus ratio (I–V): 1, 1.25, 2.25, 1.75, 3.5. Thorax ( Fig. 2A–B ). Scutum light brown with brown medial stripe enlarged anteriorly extending from anterior to medial portion, and brown lateral stripe extending from prescutal to prescutellar area. Acrostichal and dorsocentral setae complete; ante-alar area with ca. 5 elongated setae. Antepronotum brown with 5–10 setae. Postpronotum light brown with 5–15 setae. Anterior and posterior anepisternum brown with posteroventral portion of posterior anepisternum pale. Katepisternum brown and bare. Anepimeron, laterotergite, metepisternum, metepimeron, and meron brown. Scutellum brown with ca. 10 elongate setae. Mediotergite brown. Legs ( Fig. 1A ) Ratio (n = 10): fore leg (13, 12.25, 10.5, 4, 2.5, 1, 1.5), mid leg (12.2, 11.4, 9, 3.2, 2.2, 1, 1.2) and hind leg (11.4, 12.6, 10.4, 3.8, 2.2, 1, 1.2). Coxae light brown; fore and mid coxae with setae anteriorly, and hind coxa anterolaterally. Trochanters light brown. Femora brown with light brown basal portion. Tibiae and tarsomeres brown. Fore and mid tibiae swollen apically with one apical spur; fore tibia with a patch of elongated setae on bulge. Hind tibia strongly swollen apically, bulge with a patch ca. 10–30 thickened setae, with a longitudinal cleft on inner portion and one apical spur. Hind tibia spur twice than fore and mid tibiae spur. Claws with basal combs with elongated teeth. Foretarsal claw: inner claw with three ventral teeth and one dorsal tooth, and outer claw with two ventral teeth and one dorsal tooth. Mesotarsal claw: equal claws, two ventral teeth and one dorsal tooth. Metatarsal claw: equal claws, no pectinated, with only one dorsal tooth. Wing ( Fig. 2C ) (n = 10; length: 2.9 mm; width: 1 mm) with membrane hyaline. Wing veins light brown and setose. Vein Sc ends basal to Rs origin. Vein R 2+3 curved, branched and with the origin near to crossvein r-m origin. Vein M 1+2 bifurcated, M bifurcation ends near to R 2+3 branch origin. Crossvein m-m weak and near to the crossvein r-m terminus. False vein distinct and parallel to CuA, reaching ca. the basal 2/3 of CuA. Vein CuP ends apical relative to Rs origin. Length ratios R 2+3 /R 3, M 1+2 /M 2 = 0.55, and 1.25, respectively. Halter light brown. Abdomen light to dark brown with light brown parts on tergites. Terminalia ( Fig. 3A–D ) uniformly brown. Tergite IX with pronounced convex posterior margin with scattered elongated setae. Sternite IX with posterior margin with concave area, and lateral margin with ca. 3–5 elongated seta. Tergite X wider than long, with distinct lateral projection extending from the medial portion of the central plate to the anterior portion, small concave area in apical portion, membranous central plate with anterior portion projecting medially (not fused in the middle), with 3+3 setae in subapical and apical portions ( Fig. 3F ). Gonocoxite wider than long, gonocoxal apodeme elongated and its ventral portion with scattered setae. Apical gonocoxal lobe dark brown, prominent with robust basal portion, 0.6x length of gonostylus (dorsal view), stem with three elongated setae in the basal portion and one elongated seta in the middle, apex curved with two small apical setae ( Fig. 3E ). Gonostylus cylindrical, setose, with scattered elongated setae (mainly on inner portion) and truncate apex ( Fig. 3E ). Parameres sinuous, V shape (lateral view), and margin distinctly sclerotized ( Fig. 3G ). Aedeagus narrow, anterior portion bifurcated, lateral portion elongated reaching the gonocoxal apodeme apex ( Fig. 3H ).

Female. As for male, except: Body length: 3.2 mm (n = 11) ( Fig. 1B ) Head: Antenna 0.5x length of the wing. Flagellomere I 1.7x length of flagellomere II. Maxillary palpus ratio (I–V): 1, 1.25, 2.8, 2.6, 3,5. Thorax: Antealar area with 5–10 elongated setae. Anepimeron brown with dorsal portion light brown. Legs: Ratio (n = 12): fore leg (11.6, 11.4, 8.4, 3.4, 2.4, 1, 1.2), mid leg (13.2, 12.4, 9, 3.6, 2, 1, 1.2), and hind leg (12.4, 13.8, 11.4, 4, 2.6, 1, 1.2). Claws simple. Wing ( Fig. 2D ) (n = 10; length: 3.4 mm; width: 1.3 mm): Vein Sc ends basal or near to Rs origin. Crossvein r-m ends apical or near to crossvein m-m origin. Veins R 2+3 /R 3, M 1+2 /M 2 length ratios = 0.58, 1.3, respectively. Terminalia ( Fig. 4 ): Spermatheca rounded and light brown ( Fig. 4A ). Sternite VIII slight longer than wider, light brown, with posterior portion concave, wider than anterior portion, and setose. Tergite IX brown and setose. Sternite IX brown, undivided piece, strip-shaped, with one pair of projection anteriorly on medial portion and one pair of projection laterally on lateral portion ( Fig. 4B ). Segment X brown, undivided piece, setose, with lateral projection reaching the base of the cercus, and medial portion with two small lateral projections posteriorly with 2–3 elongated setae. Cercus brown, subtriangular (in ventral view), setose, and longer than segment X ( Fig. 4C ).

Immatures. Not described.

Distribution and bionomics. This species is known from four municipalities in the Santa Catarina state, Brazil: Bom Retiro (type-locality), Grão Pará, Orleans, and Urubici ( Fig. 10 ). The immature stages are found in the vegetation along the creek banks ( Fig. 11A–B ).

Remarks. Dixella moultoni is very similar to other species that exhibit a brown coloration pattern, such as Dixella torrentia and Dixella spinosa . Characters of the male terminalia can be used to distinguish them: D. torrentia has a conical gonostylus with tapering apex, and D. spinosa has a triangular or subtriangular gonostylus with stout setae ( Fig. 8A ), while D. moultoni has a cylindrical gonostylus with truncate apex ( Fig. 3D–E ). Females of D. moultoni can be distinguished by the sternite IX: D. torrentia has a greatly reduced pair of medial projections, and D. spinosa has highly developed and broad lateral projections ( Fig. 9B ), while D. moultoni has a prominent pair of medial projections and slender lateral projections ( Fig. 4B ).

Etymology. The specific name ‘ moultoni ’ is in honor of Dr. John K. Moulton, expert in the group who has been continuously contributing to the knowledge of Dixidae .

Figures

FIGURE 1. Dixella moultoni sp. nov., habitus: (A)—♂, (B)—♀. Scale bar: (A) 0.7 mm, (B) 0.8 mm.

FIGURE 2. Dixella moultoni sp. nov. (A)—♂, Head and thorax, lateral view; (B)—♂, Head and thorax, dorsal view; (C)—♂, Wing; (D)—♀, Wing. Scale bar: (A) 0.2 mm, (B–D) 0.3 mm. Abbreviations: CuA = anterior branch of cubital vein; CuP = posterior branch of cubital vein; M1 = first branch of media; M2 = second branch of media; M3+4 = third and fourth branch of media; m-m = medial crossvein; R1 = anterior branch of radius; R2 = upper branch of second branch of radius; R3 = lower branch of second branch of radius; R2+3 = second branch of radius; R 4+5 = third branch of radius; r-m = radialmedial crossvein; Rs = radial sector; Sc = subcostal vein.

FIGURE 3. Dixella moultoni sp. nov., male terminalia: (A, D)—Dorsal view; (B)—Ventral view; (C)—Lateral view; (E)— Gonocoxite and gonostylus, dorsal view; (F)—Tergite X, dorsal view; (G)—Paramere, lateral view; (H)—Aedeagus, dorsal view. Scale bar: (A–C) 0.1 mm, (D, F) 0.05 mm, (E, G–H) 0.03 mm. Abbreviations: aed = aedeagus; ap lob = apical gonocoxal lobe; gon ap = gonocoxal apodeme; goncx = gonocoxite; gonst = gonostylus; par = paramere.

FIGURE 4. Dixella moultoni sp. nov., female terminalia: (A)—Ventral view; (B)—Sternite IX; (C)—Cercus and segment X, ventral view. The black and red arrows in Fig. B highlight the medial and lateral projections, respectively. Scale bar: (A) 0.1 mm, (B–C) 0.04 mm. Abbreviations: cer = cercus; seg X = segment X.

FIGURE 8. Dixella spinosa sp. nov., male terminalia: (A)—Dorsal view; (B)—Tergite X, dorsal view. Scale bar: (A) 0.05 mm, (B) 0.03 mm Abbreviations: aed = aedeagus; ap lob = apical gonocoxal lobe; gon ap = gonocoxal apodeme; goncx = gonocoxite; gonst = gonostylus; par = paramere.

FIGURE 9. Dixella spinosa sp. nov., female terminalia: (A)—Ventral view; (B)—Sternite IX; (C)—Cercus and segment X, ventral view. Scale bar: (A) 0.1 mm, (B–C) 0.04 mm. Abbreviations: cer = cercus; seg X = segment X.

FIGURE 10. Distribution map of Dixella species in Santa Catarina state, Brazil.

FIGURE 11. Some locations in Santa Catarina state, Brazil: (A–B)—Bom Retiro; (C)—Grão-Pará; (D)—Cascata Avencal, Urubici. Photos by André Amaral.