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 ) ameliae Casal Culex ameliae Casal, 1967 : 29 (M*). Type locality: between San Pedro and Eldorado, 10 km from San Pedro , Misiones, Argentina (INM). Adult males and females of Cx. ameliae were well diagnosed by Casal. In addition to the characteristic genitalia in the male, both sexes show a unique character, the presence of short, filiform tan scales on the mesopostnotum ( Fig. 1 ). FIGURE 1. Photograph of the mesopostnotum (Mpn) of the female of Culex ( Culex ) ameliae Casal. This feature makes the species sufficiently different from other Cx. ( Cux. ). Harrison & Bickley (1990) , when reviewing the presence of ornamentation on the mesoposnotum of Culicidae , mention that only some species of the Culex subgenera Melanoconion Theobald and Carrollia Lutz possess mesopostnotal scales/setae. They did not mention the subgenus Culex , which includes 198 species (Mosquito Taxonomic Inventory 2007), some of which exhibit with exceptional and many polymorphic features. There was no mention of Cx. ameliae , although Casal (1967) mentioned the character in the original description. PUPA ( Fig. 2 ). Placement and character of setae as figured; range and modal number of branches in Table 1 . Cephalothorax ( Fig. 2 a): integument lightly tanned, homogeneously colored, maxillary palpus, distal extreme of legs and posterior of scutum sometimes slightly darker, metanotum evenly tanned, sometimes lighter laterally. Trumpet almost cylindrical, tanned, length 0.76–0.91 mm ( 0.84 mm ), width 0.08–0.13 mm ( 0.10 mm ), index 7–10 (8.45). Abdomen ( Fig. 2 b): length 3.35–4.00 mm ( 3.57 mm ); integument yellowish. Seta 1-I with 8–28 aciculate branches. Setae 4,6,8-IV with secondary short branches at apex. Seta 9-VIII with variable number of branches. Genital lobe : slightly tanned in both sexes, males: length 0.20–0.25 mm ( 0.22 mm ); females: length 0.10–0.11 mm . Paddle : length 0.85–1.09 mm ( 0.96 mm ), width 0.44–0.63 mm (0.50); index 1.34–1.73 (1.52). Yellowish to slightly tan, midrib strong, extending length of paddle. Seta 2-Pa between 0.25-0.50 length of 1-Pa. TABLE 1. Number of branches for pupal setae of Culex ( Culex ) ameliae Casal (10 specimens, modes in parenthesis). Seta Cephalothorax Abdominal segments Paddle no. CT Pa I II III IV V VI VII VIII 0 - - - 1 1 1 1 1 1 1 1−3(3) 8−48 8−11 (9) 5−10(8) 4−6(5) 2−5(5) 2−4(4) 2,3(3) - 1 2 1 1 1 1 1 1 1 1 - 1 3 2−3(2) 1,2(2) 1−3(3) 2,3(2) 2−5(3) 1−3(1) 1−3(1) 1−3(3) - 4 1−3(2) 3,4(4) 2−4(2) 1−4(2) 1−5(1) 2−4(4) 1−4(4) 1,2(2) 1,2(2) LARVA (fourth-instar) ( Fig. 3 ). Placement and character of setae as figured; number of branches in Table 2 . Head ( Fig. 3 a): slightly wider than long, width 1.35 mm , length 1.0 0 mm, collar narrow. Dorsomentum with pointed teeth, 6 or 7 teeth on each side of median tooth, lateral teeth slightly longer than the others. Setae 1,3-C single, setae 0,2,16,17-C absent. Antenna : length 0.34–0.75 mm , aciculate. Seta 1-A fanlike with 20–22 aciculate branches, inserted 0.46–0.55 mm from base. Setae 2–4-A longer than in other Culex ( Culex ) . Thorax ( Fig. 3 b): integument hyaline, with spicules up to 10 µm long. Seta 4-M subequal to 5-M, longer than in other Cx. ( Cux. ). Seta 6-M conspicuously longer than 1,3-M. Setae 10-P and 12-M long, 0.21 and 0.19 mm respectively. Abdomen ( Fig. 3 b): integument hyaline, with spicules about 10 µm long. Setae 0,14-I–VI at most 1 µm in length. Setae 1,2- I,II very short. Segment VIII ( Fig. 3 c): seta 4-VIII with 6 branches, comb with 51, 52 scales arranged in 2 rows. Siphon ( Fig. 3 c): length 2.08–2.24 mm , width 0.26–0.28 mm . Pecten with 17–19 spines with 2 basal denticles. Seta 1-S in 10 pairs, most basal arises beyond pecten, 1i-S not in line with the others. Segment X ( Fig. 3 c): saddle complete, length 0.27–0.30 mm , with spicules on dorsal surface and caudal border. Setae 2,3-X strongly developed. Seta 4-X in 6 pairs. Anal papillae long and slender, dorsal pair longer than ventral pair.

5 6 7 8 9	1−2(2) 3−4(3) 1−2(1) 2−4(3) 1−2(1)	1 1 1 1 1	2,3(2) 1−3(1) 1 1 1	2,4(2) 3−5(3) 1−3(2) 1−5(3) 1	1−5(3) 2−4(2) 1−3(1) 1−3(3) 1	1,2(2) 2,3(3) 1−4(1) 1,3(3) 1	1,2(2) 2,3(2) 1 2,3(3) 1	1,2(1) 3−6(3) 1 1−3(3) 1	- - - - 2−10
10	2−3(3)	-	-	1	1,2	1	1	1	-
11 12	2−3(3) 2−5(2)	- -	- -	1 -	1 -	1 -	1 -	1 -	- -
13	-	-	-	-	-	-	-	-	-
14	-	-	-	1	1	1	1	1	1

FIGURE 2. Pupa of Culex ( Culex ) ameliae Casal : a, cephalothorax; b, metanotum and abdomen. CT = cephalothorax; Dap = dorsal apotome; GL = genital lobe; MK = median keel; Mtn = metanotum; Pa = paddle; T = trumpet; I–IX = abdominal segments. FIGURE 3. Larva of Culex ( Culex ) ameliae Casal : a, head; b, thorax and abdominal segments I–VI; c, abdominal segments VII,VIII,X and siphon. A = antenna; C = cranium; CS = comb scale; PS = pecten spine; S = siphon; I–VIII,X = abdominal segments. The positions shown in the figure may not be accurate due to having been drawn from exuviae. TABLE 2. Number of branches for fourth-instar larval setae of Culex ( Culex ) ameliae Casal (3 exuviae). Seta Head Thorax Abdominal segments no. H P M T I II III IV V VI VII VIII X 0 - 10,11 - - 1 1 1 1 1 1?? - 1 1 1 1 1 3,4 3 1,3 4 4 3,4 5,6 3 2,3 2 - 1 3 2 2 2 1,2 1 1 1 2 1 2 3 1 1 1 3 1,4 1,3 1 1 1 1 1 4,7 1 4 1,2 2 1,2 3 1,5 3,5 1,3 1 1 3,4 1 6 12 5 4 1 1 1 2 2,3 3 4 3 2 1,2 3,5 - 6 3,4 1,2 1 1,2 3 3 2 2 2 2 4,6 - Siphon 7 2,8 2,3 1 1,6 1,2 2,3 4,5 4,6 5,6 6 1,6 1a-S 4 8 2-4 2 5,6 9,15 - 1,2 1 1 2 1,4 1 1b-S 4 9 5 1 1,4 1 2 1,4 1 3 1 1 3 1c-S 4,5 10 2 1 1 1 1 1 1,2 1 1 1 1 1d-S 3,5 11 2 3 2 7 4 3,7 1,2 1 1 1 2 1e-S 4,5 12 2,3 1 1 1 2,3 2 1 1 1 1 1 1f-S 4,5 13 2 - 12,23 6 4,7 4,18 5,12 4 4 22,23 4 1g-S 4 14 1,2 1 14,16 - 1 1 1 1 1 1 1 1h-S 4,5 15 3,5 - - - - - - - CS Pecten 1-A 1i-S 3,4 51,52 17,19 20,22 1j-S 4 ? = not counted. Material examined. 10Pe, 3Le as follow: ARGENTINA , Misiones Province, between San Pedro and Eldorado, 10 km from San Pedro ( 26º 24´49.1´´ S – 54º 30´36.1´´ O ), 11-III-1966 , García & Casal coll. Paratypes have the following numbers: Ga 137-31; Ga 136-21; Ga 131-105; Ga 137-102; Ga 137-104; Ga 131-106; Ga 131-111; Ga 132-104; Ga 132-105; Ga 132-106. Distribution. Culex ameliae is known only from Argentina (Walter Reed Biosystematics Unit 2001), and is considered endemic to the type locality ( Campos & Maciá 1998 ). Bionomics. Larvae of Cx. ameliae were collected in association with larvae of Cx. ( Melanoconion ) intrincatus Brethès, Cx. ( Mel. ) bejaranoi Duret, Cx. ( Cux. ) chidesteri Dyar and Cx. ( Cux. ) dolosus (Lynch Arribálzaga) ( Casal 1967 ) . Casal mentioned only that the larvae were collected in a flooded depression. Taxonomy. The larva of Cx. ameliae is very similar to the larva of Cx. chidesteri . The latter differs from Cx. ameliae in the following characters: the length of seta 4-M is less than 0.50 of 5-M, the thorax has spicules longer than 10 µm, the siphon is darker, seta 1a-S is inserted within the pecten and the last pecten spine is more widely separated from the others.