Culicoides insignis 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 : 784-789

Culicoides insignis Lutz, 1913

( Figs 17–28 )

Culicoides insignis Lutz, 1913: 50 (male, female, pupa, fig. wing; Brazil); COSTA LIMA (1937: 415) (fig. palpus; Brazil); FLOCH & ABONNENC (1942: 1) (fig. wing, palpus; French Guiana ) ; BARBOSA (1947:20) (fig. male genitalia); FOX (1948: 25) (notes on female); BARBOSA (1952: 16) (notes on Lutz collection) ; WIRTH & BLANTON (1956: 319) (redescr., male lectotype design., distrib.); FORATTINI et al. (1956: 195) (larva, pupa; Brazil); FORATTINI (1957: 223) (redescr., distrib.); WIRTH & BLANTON (1959: 285) (redescr., figs; Panama); WILLIAMS (1964: 463) (habitat larva; Trinidad); LINLEY (1965: 57) (pupa; Jamaica); CAVALIERI & CHIOSSONE (1966: 148) ( Argentina); WIRTH (1974: 25) (catalog, species south of USA) ; WIRTH & BLANTON (1974:57) (redescr.; Antilles ) ;AITKEN et. al. (1975: 130) ( Trinidad); BLANTON & WIRTH (1979: 106) (female, male genitalia, pupa, figs.; Florida records); SPINELLI & WIRTH (1985: 52) (in key, wing photo); WIRTH et al. (1988: 16) ( Neotropical atlas, wing) ; SPINELLI & RONDEROS (1991: 86) ( Uruguay); SPINELLI & WIRTH (1993: 34) (list of Argentinean species) ; SPINELLI et al. (1993: 53) (in key, wing photo, diagnosis, pupa); BORKENT & WIRTH (1997: 71) (world catalog); SPINELLI (1998: 325) (list of Argentinean species) ; RONDEROS & SPINELLI (1998: 79) (key); BORKENT & SPINELLI (2000: 34) (catalog, species south of USA); SPINELLI et al. (2005: 139, 142) (key, wing photo; Argentina); SPINELLI & RONDEROS (2005: 63) (wing); BORKENT & SPINELLI (2007: 68) ( Neotropical catalog) ; BORKENT & GROGAN (2009: 14) ( Nearctic catalog) ; RONDEROS et al. (2011: 1188) (list of Argentinian species) ; BORKENT (2013: 86) (online catalog).

Culicoides inamollae Fox & Hoffman, 1944: 110 (male, female; Puerto Rico).

Culicoides painteri Fox, 1946: 257 (female; Honduras).

Specimens examined. All the specimens were collected as pupa, reared in laboratory. ARGENTINA: CORRIENTES: arroyo Ambrosio, 15.ix.2010, 28°15′16.4″S 58°50′33.6″W, 44 m, 1 J ‘ex pupa’, F. Díaz leg. ENTRE RÍOS: Santa Ana, 23.ix.1984, 1 J, 1 ♀ ‘ex pupa’, Balseiro-Spinelli leg. BUENOS AIRES: Magdalena, arroyo Zapata, 15.xii.1981, 1 ♀ ‘ex pupa’, G. Spinelli leg.

Description. Male pupa ( Figs 18 , 21–22 , 25–28 ). Exuvia brown. Total length 2.82 mm. Cephalothorax length 1.073 mm. Dorsal apotome ( Fig. 21 ) dark brown, slightly wider than long, distal margin rounded, bearing a short pointed projection; disc surface covered with spinules; tubercle of dorsal apotome sensilla well-developed, with quadrangular base; DA- 1-H medium-sized, stout, pointed seta of 0.037 mm, DA-2-H pore; dorsal margin nearly straight, posterior half surface wrinkled; DAL 0.156 mm; DAW 0.182 mm; DAW/DAL 1.17. Respiratory organ elongated, uniformly brown, basal half surface with short scale-like spines; 6 apical pores; pedicel stout, pedicel length 0.074 mm, RO length 0.186 mm, P/RO 0.40. Cephalothoracic sensilla as follows: dorsal cephalic sclerite sensilla ( Fig. 25 ) conspicuous, with three sensilla, DL-1-H long, thin seta, DL-2-H medium-sized seta, stout, DL-3-H campaniform sensillum; anterolateral sensilla ( Fig. 25 ) moderately developed, with three sensilla, AL-1-T short, thin seta, AL-2-T medium-sized, thin seta, AL-3-T campaniform sensillum; anteromedial sensillum ( Fig. 25 ) short, thin; dorsal setae ( Fig. 26 ) as follows: D-1-T spur, D-2-T, D-3-T campaniform sensillum, D-4-T thin, medium–sized, D-5-T short, SA-2-T campaniform sensillum. Three ocular sensilla ( Fig. 18 ), O-1-H stout, long seta, O-3-H thin, short seta, O-2-H campaniform sensillum; two clypeal/labral thin sensilla ( Fig. 18 ), CL-1-H long seta, CL-2-H short seta. Abdominal segments integument spiculated. First abdominal segment ( Figs 27 ) with setae as follows: D-2-I and D-3-I short, thin setae, D-7-I pore; L-1-I and L-3-I minute seta, L-2-I medium-sized, stout seta; D-8-I, D-9-I short, thin setae, D-4-I pore. Fourth segment with all tubercles with small and flattened base ( Fig. 28 ): 7 dorsal setae: D-2-IV spur-like seta, D-3-IV, medium-sized, thin seta; D-5-IV minute seta, D-4-IV, D-7-IV without setae, D-8-IV, D-9-IV short setae, D-8-IV stouter; 4 lateral setae, L-1-IV, L-2-IV, L-4-IV spur–like setae, L-3-IV long, thin seta; 3 ventral setae: V-5-IV minute seta, V-6-IV, V-7-IV short, thin setae. Segment 9 ( Fig. 22 ) approximately 1.25× longer than greatest width, length 0.234 mm, width 0.186 mm, with posteriorly directed spicules restricted dorsally to mesal area; terminal processes triangular, short, subparallel with pointed, dark tips; length 0.092 mm; surface covered by sparse spicules.

Female pupa ( Figs 17, 19–20 , 23–24 ). Similar to male with following sexual differences. Total length 2.56 mm. Dorsal apotome ( Fig. 23 ) DAL 0.149 mm; DAW 0.158 mm; DAW/DAL 1.06. Respiratory organ ( Figs 17, 19 ) length 0.17–0.19 (0.18; n = 2) mm; width 0.03–0.042 (0.036, n = 2) mm; pedicel length 0.034 –0.036 (0.035; n = 2); P/RO 0.185 –0.201 (0.193; n = 2). Cephalothorax ( Fig. 17 ) length 1.10 mm, width 0.56 mm. Dorsal setae as in Fig. 20 . Segment 9 ( Fig. 24 ) with dorsomesal spicule patch extending to terminal processes; length 0.204 –0.216 (0.21; n = 2) mm, width 0.175 –0.200 (0.187; n = 2) mm; terminal processes length 0.060 –0.062 (0.061; n = 2) mm.

Taxonomic notes. Of the 39 Neotropical species of Culicoides in the subgenus Hoffmania Fox, 1948 , only five have been described as pupae: C. annettae Spinelli & Borkent, 2004 , C. charruus Spinelli & Martinez, 1992 , C. hylas Macfie, 1940 , C. insignis Lutz, 1913 and C. maruim Lutz, 1913 .

The pupae of those species are very similar. The main differences observed between them are the following: the pupa of C. charruus which was fully described ( RONDEROS et al. 2008) has the dorsal apotome shorter without a mesal projection; the respiratory organ is slightly broader at apex and truncate, with 12–16 apical pores; the anterior ocular sensilla (O-3-H) are longer; the clypeal/labral sensilla are one minute seta, the other a pore; the D-5-IV sensilla of fourth abdominal segment is long and thin and the terminal processes of segment 9 are longer. The pupa of C. annettae ( SPINELLI & BORKENT 2004) has more spinose respiratory organ and the pores are distributed in a row along its apical half. The pupa of C. maruim which was poorly described (SPINELLI et al. 1993) is pale yellowish and its respiratory organ has 7 apical pores. The description of the pupa of C. hylas ( FORATTINI 1957) is incomplete, nevertheless it shows that the respiratory organ has 17 apical pores and the tips of the terminal processes are not dark.

Distribution. USA, Mexico, Central America and Caribbean to eastern Argentina (Corrientes, Entre Rios, and Buenos Aires provinces).

Figures

Figs 17–20. Culicoides insignis Lutz, 1913. 18 – male pupa; 17, 19–20 – female pupa; 17 – cephalothorax, ventral view; 18 – clypeal/labral sensilla and ocular sensilla; 19 – dorsal apotomal sensillum, cephalothoracic sensilla and respiratory organ; 20 – dorsal setae. Scale bars:0.05 mm.Abbreviations: AN – antennae; CL-1-H, CL-2-H – clypeal/ labral sensilla; DA-1-H – dorsal apotomal sensillum; DL-1-H, DL-2-H, DL-3-H – dorsolateral cephalic sclerite sensilla; D-1-T, D-2-T, D-3-T, D-4-T, D-5-T – dorsal setae; O-1-H, O-2-H, O-3-H – ocular sensilla; P – pedicel; p – pores; RO – respiratory organ; SA-2-T – supraalar.

Figs 21–24. Culicoides insignis Lutz, 1913. 21–22 – male pupa; 23–24 – female pupa; 21, 23 – dorsal apotome; 22, 24 – 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 25–28. Culicoides insignis Lutz, 1913, male pupa: 25 – cephalothoracic sensilla; 26 – dorsal setae; 27 – first abdominal segment chaetotaxy; 28 – 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, DL-3-H – dorsolateral cephalic sclerite sensilla; D-1-T, D-2-T, D-3-T, D-4-T, D-5-T – dorsal setae; 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.