Description of the immature stages of Culex (Culex) ameliae Casal and Culex (Culex) articularis Philippi (Diptera: Culicidae) Author Laurito, Magdalena Author Almirón, Walter Ricardo Author Rossi, Gustavo Carlos text Zootaxa 2011 2778 58 68 journal article 10.5281/zenodo.202653 70d2739e-5974-4e67-b3a4-3aadd66bf733 1175-5326 202653 Culex ( Culex ) articularis Philippi Culex articularis Philippi, 1865 : 596 (A). Type locality: Casa Pangue, Llanquihue, Chile (USNM). Stone et al. 1959 . Dyar 1928 : 358 (M*, F). Lane 1951 : 334 (syn. of archegus Dyar ). Lane 1953 : 362 (M*, F). Forattini 1965 : 145 (M*). Bram 1967 : 23 (M*, L*; syn., neotype designation). PUPA ( Fig. 4 ): Placement and character of setae as figured; number of branches in Table 3 . Cephalothorax ( Fig. 4 a): integument yellowish, homogeneously colored; distal half of maxillary palpus and median keel slightly tan, metanotum yellowish to tan. Trumpet conical to cylindrical, uniformly tanned, length 0.56–0.67 mm , width 0.12– 0.17 mm , index 3.94–4.67. Abdomen ( Fig. 4 b): length 2.74–3.62 mm ; integument yellowish, medio-apical and basal area of each segment slightly tan. Seta 1-I fanlike with 20–35 aciculate branches. Setae 9-II ,IV,VII longer (more than double) than 9-I ,III,V,VI. Genital lobe : tan, smooth in both sexes, males: length 0.25–0.40 mm , wrinkled ventrally; female: length 0.17 mm . Paddle : length 0.87–0.92 mm , width 0.69–0.80 mm ; index 1.24–1.29; yellowish, smooth, midrib thick and strong, as long as paddle. Seta 2-Pa stronger than 1-Pa. TABLE 3. Number of branches for pupal setae of Culex ( Culex ) articularis Philippi (3 specimens).

Seta no.	Cephalothorax CT	Abdominal segments I II III	IV	V	VI	VII	VIII	Paddle Pa
0 1	- 4,5	- 1 1 20−35 7−15 7,8	1 5−8	1 3−6	1 3,4	1 2−5	1,2 -	- 1
2	3,4	1,2 1 1	1	1	1	1	-	1
3 4 5	2−4 3 3−5	2,3 2 2 4,5 4 1−4 1−3 5,6 4−8	3,4 1,2 2−5	1,2 4 2	1 2 2	2 1,2 1,2	- 1,2 -	- - -
6 7 8	4 2−5 6,7	1 1 1−3 2 1 1,2 - - 1−3	5 1,2 1,2	3,4 3,4 1,2	4 1 2	3 1 2	- - -	- - -
9 10	2 6,7	1 1,2 1 a - 2,3	1,2 1,2	1 1	1 1	3,4 1	4−7 -	- -
11	2	a - 1	1	1	1	1,3	-	-
12	2,3	- - -	-	-	-	-	-	-
13	-	- - -	-	-	-	-	-	-
14	-	- - 1	1	1	1	1	1	-

a = not found, alveolus without seta. LARVA (fourth-instar) ( Figs. 5 , 6 ): Placement and character of setae as in Fig. 5 ; range and modal number of branches in Table 4 . Head ( Fig. 5 a): wider ( 1.40 mm ) than long ( 1.06 mm ), oval, heavily tanned, distal half of lateralia lighter. Hypostomal suture extends to collar. Collar narrow, brown. Dorsomentum brown ( Fig. 5 b), teeth pointed, not sharp, with 7 or 8 teeth on each side of median tooth. Maxilla ( Fig. 6 ): 6- Mx single, 1.53 longer than 14-C. Setae 0,2-C single, in dorsal position, setae 1,3,4-C also single, setae 5–7-C fanlike with aciculate branches, 15-C generally triple, 16,17-C absent. Antenna : length 0.56–0.62 mm ( 0.58 mm ), tanned; basal ring darker. Spicules uniformly distributed, shorter and more evident on distal third. Seta 1-A fanlike with 20–26 aciculate branches, inserted 0.39–0.46 mm ( 0.41 mm ) from base. Thorax ( Fig. 5 c): integument hyaline, apparently glabrous, minute spicules 2.5–5.0 µm or shorter, exceptionally up to 10 µm. Tubercles of large dorsal setae tanned, tubercles of setae 9–12-M,T with 2 strong, sclerotized denticles, lateral to seta 12-M and/or 10-T, or with a crown of 5–7 sclerotized denticles. Setae 1–8,12-P aciculate, seta 4-P 0.70 length of 1-P. Seta 1-M quadruple in general, length 0.26–0.34 mm ( 0.29 mm ). Seta 1-T 0.11–0.13 mm ( 0.12 mm ) long, setae 7,9,10-T with aciculate branches. Abdomen ( Fig. 5 c): integument hyaline, coverd by minute spicules 2,5–5.0 µm. Setae: 6-I–VI; 7-I ; 12-V ; 1-VII and 1,3,5-VIII aciculate. Segment VIII ( Fig. 5 d): with more and longer spicules (7.5–10 µm) than the other segments. Comb with 40–50 scales arranged in 4 rows, fringed apically and/or marginally. Siphon : length 1.41–1.55 mm ( 1.50 mm ), width 0.31–0.35 ( 0.32 mm ), index 4.03–5.21 (4.68). Uniformly tanned, including acus, basal margin darker. Pecten on basal 0.23 with 10–14 spines, with 2 or 3 basal denticles. Seta 1-S in 5 pairs distal to pecten, seta 1d-S not in line with the others. Length of seta 1a-S 0.87 width of siphon. Setae 2,6,9-S single. Segment X : saddle complete, length 0.35–0.40 mm ( 0.37 mm ), tanned, basal margin, dorsal and middle of posterior margin slightly darker. Segment covered with spicules that are more evident on posterior margin. Siphon/saddle index 3.87–4.43 (4.05). Seta 4-X in 6 pairs. Anal papillae slender, tapering toward apex, ventral pair lightly shorter than the dorsal pair. Material examined. 3Pe, 6Le, as follow: ARGENTINA , Río Negro Province, Estancia El Rincón spring of Valcheta stream ( 40º 59´26.7´´ S – 66° 40´37.3´´ O ), 05-XII-2006 , Donato coll. Distribution . Culex articularis is known from Chile , Argentina , Ecuador and Perú (Walter Reed Biosystematics Unit 2001). In Argentina it is recorded from the provinces of Neuquén, Río Negro ( Campos & Maciá 1998 ) and Chubut (Rossi & Vezzani, unpublished data). Bionomics . Larvae of Cx. articularis were collected in Río Negro Province, at 620 m . a.s.l. with dry and cold climate. The environment is a fertile lowland that feeds the most important spring of Valcheta stream (near El Rincón farm). The stream has abundant coastal vegetation of the genus Cortadeira . Culex articularis was found associated with amphipods of the genus Hyalella . TABLE 4. Number of branches for fourth-instar larval setae of Culex ( Culex ) articularis Philippi (6 exuviae, modal number in parenthesis). Seta Head Thorax Abdominal segments no. H P M T I II III IV V VI VII VIII X 0 1 9−13 (11) - - - 1 1 1 1 1 1 - - 40−50 20−26(21)

1	1	1	3−6(4)	3−6(3)	5−8(5)	3−5(3)	4	4	4	3,4(3)	3,4(3)	3−6(5)	2,3(2)
2	1	1	1−3(2)	1−3(1)	1	1	1	1,2	1	1	1	1	2,3
3	1	1	1	3−5(3)	1,2	1,2(1)	1	1	1	1	2,3(2)	8,9(9)	1
4	1	2	2	2−4(2)	8,9(8)	4−6	1,2(2)	1	1	1−5	1	1	6
5	4−6(5)	1	1	1−3(1)	2−5(3)	1−3(2)	1,2(2)	1−4(2)	1,2(1)	2−4	1−5(3)	3−6(4)	-
6	3−6(3)	1	1	1	3	3	2	2	2	2	5−13	-	-
7	6−9(8)	2	1	6−9	2	4,5(5)	6,7(7)	7−9(8)	6−9	1,2(1)	1	-	Siphon
8	4	2	4−7(5)	7−11	-	1	1	1,2(2)	1,2(2)	3,4(3)	4,5(4)	1S-a	3−5(4)
9	5−8(8)	1	3−6	4,5(5)	1,2(2)	1,2(1)	1	1	1,2(1)	1	2−4(3)	1S-b	3−5(3)
10	1,2(2)	1	1	1	1,2(1)	1	1	1	1	1	1	1S-c	3,4(4)
11	3,4(3)	3,4(4)	3	2,3	2−4	2	1,2(1)	1	1−3(1)	2−4(2)	1,2(2)	1S-d 1S-e	3−5(3) 3−5(4)
12	4,5(4)	1	1	1	2,3(3)	1−3	1,2(1)	1−4(2)	1−4(1)	1	1	-
13	3,4(3)	-	10−19	5−8(6)	2,3(3)	15−20(1 8)	3−5(4)	3−5(3)	2−5	20−28	1−6(5)	-	Pecten
14	1,2(1)	1,2(1)	15,16(15)	-	-	1	?	?	1	1	?	?	10−14
15	3−5(3)	-	-	-	-	-	-	-	-	-	-	CS	1-A

? = not counted. Taxonomy. Larvae of Cx. articularis are very similar to several species of the subgenus, including Cx. eduardoi Casal & García , Cx. brethesi Dyar , Cx. dolosus Lynch Arribálzaga , Cx. cuyanus Duret , Cx. archegus Dyar , Cx. carcinoxenus de Oliveira Castro and Cx. foliaceus Lane. The characters that distinguish Cx. articularis from these species are: pecten spines with one subapical denticle, longer antenna and saddle and higher siphon index in Cx. eduardoi ; setae 0,2-C absent, seta 1-VIII with 7−9 branches and longer saddle in Cx. brethesi ; conspicuous spicules (10−15 µm) covering the thorax and seta 3-P double in Cx. dolosus ; setae 16,17-C present and one denticle in pecten spines in Cx. cuyanus ; seta 1-S with 5 and 4-X with 4 elements, respectively, in Cx. archegus ; Cx. carcinoxenus only inhabits crab holes; and siphon index higher than 5 and seta 1-S with 4 elements in Cx. foliaceus . Furthermore, the last three species are not recorded from Argentina . Discussion. The fourth-instar larva of Cx. ameliae is distinguishable from other Cx. ( Cux. ) by the conspicuously longer seta 4-M, and the pupa by the nearly perfectly cylindrical trumpet. The dorsal position of setae 0,2-C and the medial and separated location of setae 1,2-T relative to the other dorsal setae of the same segment easily distinguish the fourth-instar larva of Cx. articularis from other species of the subgenus. The pupa is very similar to other species of Cx. ( Cux. ), but differs in trumpet shape, which varies between conical and cylindrical, and having seta 2-Pa stronger than 1-Pa.