Culex (Culex) lahillei Bachmann & Casal
Creators: name: Laurito, Magdalena
name: Almirón, Walter Ricardo
name: Rossi, Gustavo Carlos
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Culicidae
Culex
Culex lahillei

description: Culex (Culex) lahillei Bachmann & Casal
Culex lahillei Bachmann & Casal, 1962: 267 (M*, F*, P*). Type locality: Achiras, Córdoba, Argentina. Bram 1967: 72 (M*).
FEMALE. Head: integument light brown. Vertex and occiput with narrow and white decumbent scales, intermixed whitish and yellowish erect scales (variable proportion). Broad and flat white scales restricted to postgena and ocular line. Ocular setae and ocular line brown. Antenna 2.00– 2.06 mm (2.04 mm), pedicel with ochre pruinosity, basal 0.75 of Flm1 white-scaled with yellowish integument. Clypeus yellowish with velvety appearance. Proboscis 2.25–2.44 mm (2.35 mm), dorsally brown scaled; ventrally with basal 0.50 with golden scales, and distal 0.50 white-scaled; labella golden. Maxillary palpus 0.40–0.44 mm (0.42 mm), with brown to golden scales, baso-medial dorsal area with whitish scales. Thorax: scutum brown, covered with golden, narrow and long scales. White scales from anterior promontory along lateral margins to prescutellar area and forming 2 stripes in apical third of scutum between achrostical and dorsocentral setae. Acrostichal and dorsocentral setae brown. Pleural integument lighter than scutum. Antepronotum with narrow white scales; proepisternum apically with broad white scales; postpronotum with scattered narrow golden scales. Spots of broad white scales as follows: postspiracular, upper and lower mesokatepisternal (to base of prealar setae), and upper and lower mesanepimeral. Ante- and postpronotal setae brown on posterior margins, remainder of pleural setae golden: 3,5 prealar, 3–5 and 5,6 upper and lower mesokatepisternal, respectively, 8,9 and 1,2 upper and lower mesanepimeral, respectively. Pre- and postspiracular setae absent. Scutellum with narrow white scales not confined to lobes; 6,7 and 4,5 brown with golden sheen, median and lateral scutellar setae, respectively. Mesopostnotum with leather-like appearance, marginally yellowish to golden or with a longitudinal brown stripe, without scales and setae. Wing: length 3.95–4.44 mm (4.21 mm), with brown scales, most veins with narrow scales; narrow and broad scales along veins C, Sc, R, R4+5, CuA and CuP (broad scales most prevalent), M2 and M3+4 (broad and narrow in similar proportion); vein 1A with scales of intermediate thickness. Baso-posterior area of veins C and R with strip of whitish scales that cross h crossvein. Halter: scabellum yellow to brown; pedicel yellowish and whitish-scaled; capitellum brown, whitish-scaled. Legs: coxal integument yellowish, paler on C-III. Anterior and basolateral region of C-I broad and white-scaled, few brown scales on anterior area. Anterior surface with brown setae, posterior with brown setae in a longitudinal line mixed with white scales. Coxae II,III anteriorly white-scaled, posteriorly without scales; longitudinal line of long brown setae, other shorter setae near joint with trochanter and inner surfaces with brown and golden setae. Trochanters yellowish. Inner surface of Tr-I with broad whitish scales and a few brown scales, Tr-I,II with short brown setae on inner surface. Trochanter III with basal white scales and short golden setae. Femora brown- and goldenscaled dorsally, white-scaled ventrally and on distal area, lengths: Fe-I 2.15–2.40 mm (2.28 mm), Fe-II 2.30–2.38 mm (2.35 mm) and Fe-III 2.24–2.35 mm (2.31 mm). Tibiae brown- and white-scaled dorsally and ventrally, respectively, or entirely brown-scaled, inconspicuous distal ring of white scales on Ti-I, more evident on Ti-II,III; lengths: Ti-I 2.30–2.57 mm (2.45 mm), Ti-II 2.35–2.74 mm (2.61 mm) and Ti-III 2.53-2.54 mm (2.535 mm). Tarsomeres 1- 4 brown-scaled with golden sheen dorsally and whitish-scaled ventrally, Ta5 whitish-scaled. Joint between tarsomeres with a few whitish scales, ungues brown and simple. Lengths: Ta-I 1.36–1.40 mm (1.39 mm), Ta-II1 1.50–1.61 mm (1.57 mm), Ta-III1 2.37–2.40 mm (2.38 mm); Ta-I2 0.66–1.07 mm (0.83 mm), Ta-II2 0.79–0.85 mm (0.81 mm), Ta-III2 1.25–1.41 mm (1.35 mm); Ta-I3 0.43–0.85 mm (0.58 mm), Ta-II3 0.45–0.56 mm (0.51 mm), Ta-III3 1.00– 1.0 7 mm (1.04 mm); Ta-I4 0.25–0.35 mm (0.29 mm), Ta-II4 0.29–0.31 mm (0.30 mm), Ta-III4 0.50–0.72 mm (0.63 mm); Ta-I5 0.15–0.19 mm (0.18 mm), Ta-II5 0.17–0.20 mm (0.19 mm), Ta-III5 0.27–0.32 mm (0.29 mm). Abdomen: integument tanned. Tergum I with golden setae and midapical spot of brown scales and some whitish on midline. Terga II–VII with golden setae on apical margin, brown-scaled with golden sheen, white scales as follow: II- Te in a longitudinal line not reaching apical margin; III-Te forming a complete basal band up to 0.30 length of segment or as a basomedial spot with a few scales scattered to basolateral area; IV–VI-Te, complete basal band up to 0.25–0.37, 0.33–0.39 and 0.33–0.35 length of segments, respectively; VII-Te, complete basal band up to 0.13–0.19 in middle, reaching 0.59–0.66 laterally; VIII-Te, entirely white-scaled, golden scales on apical margin. Sterna I–III white-scaled or white and brown-scaled, the last, restricted to midline; IV–VII-S white- and brown-scaled, triangular patch from base to apical margin on midline; VIII-S white-scaled, midline without scales. Genitalia (Fig. 1): Cerci, length 0.16–0.17 mm, width 0.0 9 mm, narrower at base than apex, stronger and more abundant setae on distal and lateral margins; caudal margin of postgenital lobe convex; insula normal with 6,7 setae; IX-Te with 6–8 setae on each side.
MALE. Like female except for sexual differences. Head: vertex and occiput with white, narrow and broad, decumbent scales, postgena with broad and flat white scales. Antenna strongly verticillate, length 1.52–2.28 mm (1.86 mm), flagellomeres similar in length. Clypeus golden. Proboscis 2.02–2.64 mm (2.37 mm), golden-scaled dorsally except for white scales on middle, ventrally white-scaled except for golden scales at base and on labella. Maxillary palpus 2.40–3.27 mm (2.89 mm), Plp1,2 fused and golden scaled, Plp3 with golden scales and sometimes white-scaled laterally. Ventral surface of Plp4 and basoventral surface of Plp5 white-scaled, remainder goldenscaled. Brown setae, abundant and longer on Plp4 and apex of Plp3, Plp5 with fewer and shorter setae, Plp4,5 exceed proboscis from base of labella. Thorax: antepronotum with 5 golden setae, postpronotum with narrow white scales on apical margin and 4 brown to golden setae; other pleural setae as follows: 5,6 prealar, 2–5 and 4–7 upper and lower mesokatepisternal, respectively, 5–8 and 1 upper and lower mesanepimeral, respectively. Scutellum with 6,7 and 3,4 large median and lateral setae, respectively. Wing: length 3.22–3.85 mm (3.56 mm), narrow and broad brown scales on veins C, R and R1 (broad scales more abundant), CuA, CuP and R4+5 (broad and narrow scales in similar proportion), base of vein 1A exclusively with broad scales; whitish scales on basal section of all or at least some of following veins: C, Sc or R. Legs (Fig. 2): C-I with a spot of broad white scales on basolateral area extending to anterior surface, some brown scales on anterior region, and brown setae with golden sheen in 2 longitudinal rows, anterior and posterior. Coxa II with spot of white scales on mid-anterior area and 2 median stripes of brown setae, on outer and inner surfaces, respectively. Coxa III whitish-scaled on midline of outer surface; golden short setae on apical margin and inner and outer surfaces, brown setae in a longitudinal row on posterior part of sclerite. Inner face of Tr-I with broad brown scales and a few whitish scales, inner face of Tr-II,III with whitish scales and a few brown scales. Femora, lengths as follow: Fe-I 1.85–2.27 mm (2.07 mm), Fe-II 1.81–2.30 mm (2.13 mm) and Fe-III 1.82–2.17 mm (2.01 mm). Tibiae brown-scaled dorsally and white-scaled ventrally and on distal margin, lengths: Ti-I 1.83–2.36 mm (2.11 mm), Ti-II 2.00– 2.53 mm (2.29 mm) and Ti-III 1.76–2.41 mm (2.16 mm). Tarsomeres1–3 with brown scales dorsally and whitish scales ventrally, Ta4–5 golden-scaled. Tarsomeres I5, II5 with evident empodium and unguitractor plate on apical third, ungues brown, one more developed with secondary tooth (Fig. 2 a, b). Basal third of Ta-I5 with an acute projection (Fig. 2 a). Tarsus III brown-scaled dorsally and ventrally, ungues simple (Fig. 2 c). Tarsomeres, lengths: Ta-I1 1.04–1.27 mm (1.05 mm), Ta-II1 1.22–1.51 mm (1.40 mm), Ta- III1 1.73–2.27 mm (2.11 mm); Ta-I2 0.47–0.60 mm (0.54 mm), Ta-II2 0.64–0.76 mm (0.71 mm), Ta-III2 1.06–1.33 mm (1.25 mm); Ta-I3 0.30–0.35 mm (0.32 mm), Ta-II3 0.41–0.49 mm (0.46 mm), Ta-III3 1.00– 1.24 mm (1.06 mm); Ta-I4 0.09–0.10 mm (0.098 mm), Ta-II4 0.17–0.19 mm (0.18 mm), Ta-III4 0.46–0.68 mm (0.59 mm); Ta-I5 0.17– 0.20 mm (0.18 mm), Ta-II5 0.16–0.19 mm (0.18 mm), Ta-III5 0.26–0.29 mm (0.27 mm). Abdomen: terga brownscaled, white scales as follow: II-Te reaching apex of segment; terga III–V complete basal bands up to 0.22–0.30, 0.37–0.40 and 0.40 length of each, respectively; VI-Te with complete basal band up to 0.42–0.46 medially, reaching 0.60–0.69 laterally. Other terga lost during dissection of genitalia. Genitalia (Fig. 3): Gonocoxite short (Fig. 3 a, c), length approximately 1.86x widest part, outer border with short setae, strong setae on dorsal and ventral faces, apical area with 2–4 setae not reaching 0.25 length of gonostylus. Subapical lobe neither prominent nor divided, setae a–c, strong, rodlike, a shortest, straight with blunt apex, b and c with slightly curved apex, b broader at base than apex, c longer than b. Seta g foliform, apex angular; seta f filiform with curved apex; seta h narrowly leafshaped, slightly longer than g. External surface of gonostylus smooth, inner surface with longitudinal groove; basal 0.05–0.06 mm of external border strongly convex, inner border with gentle curvature, appearing enlarged in proximal third. Two setae on apical third of lateral face, gonostylar claw short, apex blunt. Phallosome: lateral plate (Fig. 3 b, d) with broad dorsal arm, tapering considerably in distal third, longer than teeth of lateral plate. Ventral arm tooth-like, narrower and less sclerotized than teeth of lateral plate, bent 90º over 2 ventral teeth of lateral plate; external margin strongly sclerotized. Lateral plate with 7–10 sclerotized teeth, apices blunt. Dorsal process rounded, sclerotized like teeth of lateral plate. Proctiger (Fig. 3 e): apex with a crown of lateral flattened setae and inner spiniform spicules, basolateral arm bent, apex blunt, with 4,5 cercal setae. Lobe of IX-Te small, with 5–7 setae (Fig. 3 f).
PUPA (Fig. 4). Placement and character of setae as figured, number of branches from each side of body in Table 1. Cephalothorax: integument yellowish; maxillary palpus, postscutal area and antenna tanned, metanotum yellowish, slightly tan in medial region. Setae 4–7-CT longer than usual for Cx. (Cux.), length similar to length of 2,3-CT. Trumpet cylindrical, brown, reticular area and tracheoid area differentiated, mid-region of reticular area slightly expanded; length 0.44–0.59 mm, width 0.10–0.15 mm, index 4.12. Abdomen: length 2.65 mm; integument yellowish to ocher. Seta 1-I fanlike with 10 principal branches ending in 48,54 secondary aciculate branches, seta 5-I forked 0.50–0.60 from base with 3,4 branches, seta 6-II 0.70 mm long, seta 14-II present, seta 1-V extends 0.75 length of segment VI, setae 5-IV–VI longer than following tergum. Setae 1,5-VII about half length of tergum VIII, seta 2-VII mesad of 1-VII, seta 6-VII with simple branches, setae 9-VII, VIII with aciculate branches. Seta 1-IX absent. Genital lobe (male): slightly tan, smooth, length 0.35 mm. No punctures observed. Paddle: length 0.78,0. 79 mm. Slightly tan, almost transparent, smooth; midrib thick, strong; outer margin visible entire length of paddle. Seta 1-Pa thick, single and aciculate, seta 2-Pa single.
LARVA (fourth-instar) (Fig. 5). Placement and character of setae as figured, number of branches from each side of body in Table 2. Head: wider than long, width 1.43 mm, length 0.82 mm, tanned, lateralia and posterior region of dorsal apotome darker. Hypostomal suture long, reaching collar, collar narrow and brown. Dorsomentum brown except for clearer base, with 6,7 pointed teeth on each side of median tooth. Setae 1,3-C single, simple, setae 0,2,16,17-C absent. A puncture observed aligned with seta 15-C toward base of head. Antenna: length 0.60,0. 62 mm; slightly tan, basal margin and apex darker; outer surface with spine-like spicules, between insertion of seta 1- A and apex. Seta 1-A inserted about 0.74 from base, fanlike with 18,20 aciculate branches, insertion with a minute crown of sclerotized spicules (Fig. 4 a). Setae 2–4-A long and similar in length, 6-A with pointed apex and conspicuously longer than 5-A. Thorax: integument hyaline, with minute spicules, length 5–7.5 µm. Tubercles of large dorsal setae moderately and evenly tanned. Tubercles of setae 9–12-M with a strongly sclerotized spine with divided tips, seta 10-T surrounded by crown with 4 spines (Fig. 5 c). A sclerotized plate with denticles about 12.5– 15 µm located anterior to seta 5-M (Fig. 5 c). Setae 11,14-P with simple branches, between 0.06–0.10 mm and 0.12–0.15 mm long, respectively. Setae 1–8,12-P aciculate; 9,10-P similar in length, single; setae 5–7-M single, aciculate, single; 7,9,10,13-T aciculate with 7,8; 6; 1 and 5 branches, respectively. Abdomen: integument hyaline, glabrous, except segment VIII with spicules between 5–10 µm surrounding comb scales. Seta 6-I–VII aciculate, 10-I long, reaching posterior margin of segment, 12,13-I 0.50 length of segment. Seta 7-II long, 0.75 length of 6-II; 10–12-II reaching posterior margin of segment, 13-II dendritic, seta 14-II present. Setae 1,3-III reach middle of segment IV. Puncture absent on segment III, present between setae 3,4-IV,V. Setae 1,3-V long, reaching bases of seta 6-VI. Seta 1-VI as long as segment, seta 13-VI dendritic. Sclerotized plate with denticles (similar to plate on metathorax) present between setae 6,7-I. Segment VIII: setae 1,3,5-VIII aciculate, 47,56 comb scales in 4 rows. Siphon: tanned, glabrous, basal margin and acus brown. Length 1.58 mm, width 0.32 mm, index 4.94. Pecten on basal 0.24, with 13 spines, majority with 1 basal denticle, some with 2. Seta 1-S in 6 pairs, all slightly longer than width of siphon at point of insertion, 1a-S not within distal elements of pecten, 1e-S not aligned, 1a–d-S between 0.25–0.32 mm long and 1e,f-S between 0.20–0.24 mm. Seta 8-S narrower than usual, seta 9-S curved apically. Segment X: saddle complete, tanned, basal margin and medial area of caudal margin darker, length 0.39 mm. Minute spicules on anteroventral area, more evident posterolaterally. Seta 2-X triple, branches unequal in length, longest 2.22 mm long, 0.70 length of 3-X. Seta 4-X in 6 pairs. Anal papillae stouter than usual, apices blunt, length of dorsal papillae 0.46–0.48 mm, ventral papillae 0.36–0.39 mm; width 0.11–0.12 mm.
Seta Head Thorax Abdominal segments
13 3,3 - 1,5 5,5 2,2>10,>10 4,4 4,5 5,5 26,33 3,3 - - 14 1,1 1,1 16,17 - - 1,1 1,1 1,1 1,1 1,1 1-A Pecten CS 15 3,4 - - - - - - - - - 18,20 13,13 47,56
?: not found (loss seta, only alveolus) Material examined. 5M, 4MG, 4F, 3FG, 2Pe, 1Le as follow: ARGENTINA, Córdoba Province: Achiras (approximately 33° 10´06.2´´ S – 64° 59´25.5´´ W and 830 m a.s.l.), 1M (Holotype, P 1124), 2MG (holotype, P 5219 and paratype, P 1161 in Faure with genitalia on slides a, b, c), 1F (allotype, P 1150), 1FG (allotype, P 6392), 1Pe (paratype, P 1160), 23-II-1938, Del Ponte coll.; Copina (approximately 31º 34´15.75´´ S – 64º 45´26.87´´ W and 1946 m a.s.l.), 4M, 5MG, 2F, 2FG, 1Pe, 1Le, 01-X-1995, Harbach & Almirón coll.
Distribution. Culex lahillei is known from Argentina, recorded from Córdoba and Buenos Aires provinces (Campos & Maciá 1998), the latter one dubious.
Taxonomy. The female of Cx. lahillei is very similar to several species of the genus, including Cx. (Allimanta) tramazayguesi Duret, Cx. (Cux.) apicinus Philippi, Cx. (Cux.) brethesi Dyar, Cx. (Cux.) chidesteri Dyar, Cx. (Cux.) dolosus Lynch Arribálzaga, Cx. (Cux.) fernandezi Casal, García & Cavallieri and Cx. (Cux.) maxi Dyar. It shares with all species except Cx. dolosus the presence of whitish scales at the base of vein C and/or vein Sc; with Cx. apicinus, Cx. brethesi, Cx. chidesteri and Cx. dolosus, inconspicuous joint between tarsomeres; with Cx. chidesteri, Cx. dolosus, Cx. fernandezi and Cx. tramazayguesi, the presence of white scales on the postspiracular lobe; with Cx. apicinus and Cx. fernandezi, long narrow scales on the scutum; and, finally, with Cx. tramazayguesi, Ta-III1 shorter than Ti-III (diagnostic for the subgenus Allimanta). The last character, which it shares with Cx. tramazayguesi, distinguishes Cx. lahillei from other Cx. (Cux.) species.
In summary, the characteristics that separate the female of Cx. lahillei from those of the other species include: scutal and pleural integument darker, strongly contrasting with white scales in Cx. apicinus, Cx. fernandezi and Cx. tramazaiguesi; absence of postspiracular scales in Cx. apicinus, Cx. brethesi and Cx. maxi; scutal scales long and narrow in Cx. chidesteri, Cx. dolosus, Cx. maxi and Cx. tramazayguesi; scutal scales in a pattern in Cx. apicinus, Cx. dolosus and Cx. fernandezi; and smaller general size in Cx. tramazayguesi.
Discussion. Bachmann & Casal (1962) compared Cx. lahillei with Cx. delys and Cx. tramazayguesi because they share the presence of white scales at the bases of veins C and Sc and, particularly in comparison to Cx. tramazayguesi, white scales on the postspiracular area. Bachmann & Casal distinguished Cx. lahillei from Cx. delys by the absence of white scales on some wing veins and the postspiracular area, and with Cx. tramazayguesi by the darker integument, more concave postgenital lobe of the female and the form of the basistyle and mesosome of the male of Cx. tramazayguesi. The presence of white scales at the base of veins C and Sc and on the postspiracular area are characteristics of several species in the subgenus Culex.
The trumpet of the pupa is comparable to that in Cx. apicinus, but the latter can be distinguished by the presence of seta 13-III–VI, or at least its alveolus. The characters that distinguish Cx. lahillei from other Cx. (Cux.) species are: the length of setae 4–7-CT being similar to that of setae 2,3-CT, the presence of seta 14-II and the absence of seta 1-IX in the pupa; the presence of seta 14-II, the thinness of seta 8-S and the width of the anal papillae in the larva. Based on these characteristics, the placement of Cx. lahillei in the subgenus Culex could be questionable. A more definitive decision must await the study of additional specimens.
description: Published as part of Laurito, Magdalena, Almirón, Walter Ricardo & Rossi, Gustavo Carlos, 2011, Description of the immature stages and redescription of the adults of Culex (Culex) lahillei Bachmann & Casal (Diptera: Culicidae), pp. 29-38 in Zootaxa 2915 on pages 30-38, DOI: 10.5281/zenodo.207537