Culicoides bambusicola Lutz, 1913

Marino, Pablo I., Cazorla, Carla G., Ronderos, María M., Unlp, Cepave, Conicet & Conicet, 2013, Study of the immature stages of two species of the biting midge genus Culicoides (Diptera: Ceratopogonidae), Acta Entomologica Musei Nationalis Pragae 53 (2), pp. 777-792 : 778-784

Culicoides bambusicola Lutz, 1913

( Figs 1–16 )

Culicoides bambusicola Lutz, 1913: 62 (female, larva; Brazil); COSTA LIMA (1937: 412) (in key); BARRETTO (1944:

95) (male; Brazil); LANE (1947: 166) (pupa, redescr.larva; Brazil); BARBOSA (1952: 11) (Figs larva, pupa; Brazil);

FORATTINI (1957: 321) (redescr. adult, pupa, larva; syn.: bahiensis ; type locality stated; distr.); WIRTH et al. (1988:

54) (Neotropical atlas, wing); BORKENT & WIRTH (1997: 62) (world catalog); RONDEROS & SPINELLI (2000: 134)

(redescr. larva, pupa, Argentina); BORKENT & SPINELLI (2000: 29) (catalog, species south of USA); RONDEROS &

SPINELLI (2002: 93) ( Argentina record); RONDEROS & DÍAZ (2002: 44) (rearing; Argentina, Buenos Aires record); SPINELLI et al. (2005: 138, 142) (in key, wing photo; Argentina); BORKENT & SPINELLI (2007: 64) (Neotropical catalog); BORKENT (2013: 75) (online catalog).

Culicoides bahiensis Barbosa, 1947: 11 (female, male; Brazil).

Material examined. All the specimens were collected as larvae or pupae, reared in laboratory. ARGENTINA: MISIONES: Corpus, Puerto Maní : vi.2000, 3 L4, F. Krsticevic leg. ; 23.ix.1997, 5 L4, L. Hes leg.; 17.v.2005, 1 larval exuvia, M. Ronderos leg.; ii.2001, 3JJ ‘ex pupa’, 1♀ ‘ex pupa’, G.Rossi leg.; Parque Provincial Saltos del Moconá, 27°15′60″S 53°89′16.5″W, 4.xi.2011, 4 JJ ‘ex pupa’, 1 J pupa ‘ex larva’, 1 J pupa, 3 L4, E. Lestani leg. CORRI- ENTES: Garapè : 17.vi.1999, 1 pupa, 1 L4, F.Krsticevic leg. ; Estación Biológica Corrientes (EBCo), 29.xi.2010, 2JJ ‘ex pupa’, 2 JJ ‘ex larva’, R. Campos leg. BUENOS AIRES: City Bell , 6.iii.2001, 1 ♀ ‘ex pupa’, M. Ronderos leg.

Description. Fourth instar larva ( Figs 1 – 4 ). Larva length 3.35– 5.07 (4.13, n = 6) mm. Head capsule ( Figs 1–2 ) pale yellowish, moderately elongate, apex nearly straight, HL 0.150 –0.225 (0.193, n = 12) mm, HW 0.095 –0.170 (0.13, n = 8) mm, HR 1.32–1.92 (1.566, n = 8), SGW 0.095 –0.150 (0.109, n = 6), SGR 1.13–1.35 (1.23, n = 6). All setae thin, medium–sized to elongate, except setae ‘y’ stout; chaetotaxy as in Figs 1–2 . Antenna stout ( Figs 1–2 ), short. Labrum ( Figs 1–2 ) shorter than greatest basal width, with pair of anterolateral sensilla trichoidea ( Figs 1–2 ); palatum with 2 pairs of contiguous sensilla styloconica, and 2 pairs of sensilla trichoidea underneath ( Figs 1–2 ); messors ( Figs 2–3 ) stout, poorly sclerotized, with 7–8 elongate teeth, five-toothed well developed scopae ( Fig. 3 ). Mandible ( Fig. 4 ) of medium length, stout, hooked, curved, with broad base, 7–8 short subapical teeth, 2 stout, pointed apical teeth, one insertion of setae on ectal margin near hypocondyle; ML 0.047 –0.065 (0.06, n = 9) mm, MW 0.017 –0.020 (0.019, n = 9) mm. Maxilla ( Figs 1, 2 ) with short papillae; maxillary palpus ( Figs 2, 4 ) stout, cylindrical, with 6 long apical papillae, two short, lateral papillae, hook-shaped lateral lobe; galeolacinia with long seta. Hypostoma ( Figs 1–2 ) with rounded, mesal, smooth elevation, lateral margin serrate with three stout teeth, the inner one conspicuous. Epipharynx massive, with 2 ventral combs (2 and 4), dorsal comb sclerites enlarged with fringed edge; lateral arms stout, sclerotized, with hyaline lateral curtains; LAW 0.057 –0.062 (0.06, n = 5) mm, DCW 0.020 (n = 1). Hypopharynx elongate, moderately sclerotized, arms nearly straight. Thoracic pigmentation uniformly pale, integument with notorious long setae. Abdominal segments uniformly pale. Caudal segment with 5 pairs of pale, long, thin setae; CSL 0.420 –0.490 (0.460, n = 4) mm, CSW 0.160 –0.176 (0.165, n = 3) mm, CSR 2.55–2.75 (2.63, n = 3), seta ‘o’ elongated, OL 0.300 –0.400 (0.325, n = 4), OD 0.050 –0.070 (0.060, n = 3) mm.

Male pupa ( Figs 5–10 , 13–16 ). Exuviae pale yellowish. Total length 1.72–2.32 (2.07, n = 6) mm. Length of cephalothorax 0.79–0.92 (0.85, n = 6) mm, width 0.52–0.60 (0.56, n = 4) mm. Dorsal apotome ( Fig. 9 ) as long as wide, dorsal margin nearly straight; laterodistal margins of disc surface covered by spinules; tubercle of dorsal apotome sensilla well-developed, base rounded with marginal small spines; DA-1-H elongate, stout, pointed seta, DA-2-H pore; DAL 0.149 –0.163 (0.156, n = 2) mm; DAW 0.149 –0.163 (0.156, n = 2) mm; DAW/DAL 1 (n = 2). Respiratory organ ( Figs 5–6 , 13 ) uniformly yellowish, medium-sized, stout; dorsal surface with short scale–like spines; 5–6 apical pores, 4 laterally on distal half; pedicel length 0.008 –0.012 (0.0096, n = 6) mm, RO length 0.09–0.11 (0.104, n = 6) mm, P/RO 0.08–0.108 (0.09, n = 6). Cephalothoracic sensilla as follows: two dorsolateral cephalic sclerite sensilla ( Figs 5 , 13 ) on blunt tubercle: DL-1-H long, stout seta, DL-2-H minute seta, campaniform sensillum not visible; three anterolateral sensilla ( Figs 5, 7 , 13 ), AL-1-T medium-sized, stout seta, AL-2-T long, thin seta, AL-3-T campaniform sensillum; anteromedial sensillum ( Figs 5 , 13 ) medium sized, thin; dorsal setae ( Fig. 14 ) as follows: D-1-T, D-2-T medium-sized, thin setae, D-3-T campaniform sensillum, D-4-T short seta, D-5-T minute seta, SA-2-T campaniform sensillum. Three ocular ( Fig. 8 ) thin sensilla, O-1-H long seta, O-3-H slightly shorter, O-2-H campaniform sensillum; one clypeal/labral ( Fig. 8 ) mediumsized sensillum. Abdominal segments integument spiculated. First abdominal segment ( Fig. 15 ) with sensilla as follows: D-2-I stout, medium sized seta, D-3-I thin, medium-sized setae, D-7-I pore; L-1-I, L-2-I, L-3-I medium-sized short, thin setae; D-8-I, D-9-I medium-sized, thin setae, D-4-I pore. Fourth segment with setae poorly developed ( Fig. 16 ): 7 dorsal setae, D-2-IV, D-3-IV, long, thin setae, D-2-IV stouter; D-5-IV minute seta, D-4-IV, D-7-IV without setae, D-8-IV long, stout seta, D-9-IV long, thin seta; 4 long, lateral setae, L-1-IV, L-2-IV, L-3-IV thin setae, L-4-IV stout seta; 3 ventral setae, V-5-IV short, thin seta, V-6-IV, V-7-IV, medium-sized, thin setae, V-7-IV shorter. Segment 9 ( Fig. 10 ) approximately 1.5× longer than greatest width, length 0.25–0.29 (0.27, n = 6) mm, width 0.149 –0.186 (0.174, n = 4) mm, with posteriorly directed spicules restricted ventrally to basal transverse band; terminal processes stout, short, subparallel with pointed tip; surface covered by sparse spicules, length 0.09–0.10 (0.093, n = 6) mm.

Female pupa ( Figs 11–12 ). Similar to male with following sexual differences. Total length 2.54–2.88 (2.71, n = 2) mm. Dorsal apotome ( Fig. 11 ) DAL 0.162 –0.200 (0.181, n = 2) mm; DAW 0.174 –0.200 (0.187, n = 2) mm; DAW/DAL 1.00–1.07 (1.035, n = 2). Respiratory organ length 0.122 –0.140 (0.131, n = 2) mm; width 0.048 –0.062 (0.055, n = 2) mm; pedicel length 0.010 (n = 2) mm; P/RO 0.071 –0.082 (0.077, n = 2). Cephalothorax length 1.02–1.10 (1.06, n = 2) mm, width 0.74–0.80 (0.77, n = 2) mm. Segment 9 ( Fig. 12 ) with posteriorly directed spicules restricted to narrow anterior band, not connected to central inverted V-shaped patch of spicules; mesal spicules patch not extending to terminal processes, these moderately elongated, subparallel with pointed, dark tips; ventral surface of terminal processes with spicules present on each side of midline; length 0.272 –0.320 (0.296, n = 2) mm, width 0.184 –0.240 (0.212, n = 2) mm; terminal processes length 0.09–0.11 (0.10, n = 2) mm.

Taxonomic notes. RONDEROS & SPINELLI (2000) in their last redescription of Culicoides bambusicola omitted the description of the palatum, maxilla and hypopharynx of the fourth instar larva, as well as of the cephalothoracic sensilla of the pupa. The fourth abdominal segment of the pupae was incompletely described and its sensilla were erroneously described.

In the genus Culicoides there are three sensilla on the dorsolateral sclerite: 2 setae (generally one larger, one smaller) and a campaniform sensillum (Borkent, pers. comm.). For the species with 2 setae such as C. bambusicola , there should probably be also a separate campaniform sensillum, which could not be observed in the studied material.

The subgenus Cotocripus Brèthes, 1912 ( BORKENT & SPINELLI 2007, SPINELLI et al. 2009) is represented by six species, of which only the immatures of C. bambusicola have been studied. Therefore, we compared it with C. debilipalpis , which is included in the subgenus Haematomyidium Goeldi, 1905 and develops in clean water of tree holes. The immatures of both species are very similar; the few differences between the fourth instar larvae are the following: C. debilipalpis has the antenna less conspicuous, the head ventral seta ‘y’ is stouter and mandible has two elongated, small pointed teeth, the inner tooth is smaller. The pupa of C. debilipalpis has the respiratory organ longer with large scale-like spines; the dorsal apotome has the disc surface completely covered with spines.

Distribution. Colombia, Brazil and Argentina (Misiones, Corrientes and Buenos Aires provinces).

Figures

Figs 1–4. Culicoides bambusicola Lutz, 1913, larva: 1 – head capsule, ventral view; 2 – head capsule, anteroventral view; 3 – mouthparts (messors and scopae); 4 – head capsule, detail of lateral view of mouthparts (mandible and maxilla) (from RONDEROS & SPINELLI 2000). Abbreviations: AN – antennae; CO – collar; HY – hypostoma; LC1 – lacinial sclerite 1; LB – labrum; MD – mandible; MX – maxilla; MP – maxillary palpus; MS – messors; SC – scopae; PL – palatum; ss – sensilla styloconica; st – sensilla trichoidea. Head capsule chaetotaxy: n – anterolateral pit; o – parahypostomal setae; s – anterior perifrontal setae; v – posterolateral setae; w – anterolateral setae; y – ventral setae.

Figs 5–8. Culicoides bambusicola Lutz, 1913, male pupa: 5 – cephalothoracic sensilla and respiratory organ; 6 – respiratory organ; 7 – anterolateral sensilla; 8 – clypeal/labral sensillum and ocular sensilla. Scale bars: 0.05 mm.Abbreviations: AL-1-T, AL-2-T, AL-3-T – anterolateral sensilla; AM-1-T – anteromedial sensillum; CL-1-H – clypeal/labral sensillum; DL-1-H, DL-2-H – dorsolateral cephalic sclerite sensilla; O-1-H, O-2-H, O-3-H – ocular sensilla; P – pedicel; p – pore; RO – respiratory organ.

Figs 9–12. Culicoides bambusicola Lutz, 1913. 9–10 – male pupa; 11–12 – female pupa; 9, 11 – dorsal apotome; 10, 12 – ninth segment, ventral view.Scale bars: 0.05 mm.Abbreviations: DA-1-H, DA-2-H – dorsal apotomal sensilla; GL – genital lobe; TP – terminal process; D-5-IX, D-6-IX – campaniform sensilla of terminal process.

Figs 13–16. Culicoides bambusicola Lutz, 1913, male pupa: 13 – cephalothoracic sensilla and respiratory organ; 14 – dorsal setae; 15 – first abdominal segment chaetotaxy; 16 – fourth abdominal segment chaetotaxy.Scale bars: 0.05 mm.Abbreviations: AL-1-T, AL-2-T, AL-3-T – anterolateral sensilla; AM-1-T – anteromedial sensillum; DL-1-H, DL-2-H – dorsolateral cephalic sclerite sensilla; p – pores; RO – respiratory organ; D-1-T, D-2-T, D-3-T, D-4-T, D-5-T – dorsals; SA-2-T – supraalar; D-2-I, D-3-I, D-4-I, D-7-I, D-8-I, D-9-I – dorsal sensilla of first abdominal segment; L-1-I, L-2-I, L-3-I – lateral sensilla of first abdominal segment; D-2-IV, D-3-IV, D-4-IV, D-5-IV, D-7-IV, D-8-IV, D-9-IV – dorsal sensilla of fourth abdominal segment; L-1-IV, L-2-IV, L-3-IV, L-4-IV – lateral sensilla of fourth abdominal segment; V-5-IV, V-6-IV, V-7-IV – ventral sensilla of fourth abdominal segment.