Anopheles gambiae

<p>Sub-Saharan and Central Africa [<em>Anopheles gambiae</em> sensu stricto]</p>

Sumber: The Diptera Site

Anopheles gambiae Giles, 1902 Anopheles gracilis Dönitz, 1902 Anopheles gambiae molecular S form, della Torre et al. 2001 Anopheles (Cellia) coluzzii Coetzee & Wilkerson, sp. n. Anopheles gambiae molecular M form, della Torre et al. 2001 Holotype female and associated pupal and larval exuviae. Essentially as in the descriptions of Anopheles gambiae given by Gillies & de Meillon (1968, pp. 208 – 209) and as figured by White (1985) for An. bwambae, with the following additional observations. Description. Female (Figs. 1 A – F), holotype. Head: Frontal tuft of long white scales extending well beyond base of antenna; interocular space above frontal tuft with small golden appressed fusiform scales; ocular setae pale brown near vertex, dark laterally; scales of vertex erect, long slender, pale yellow anteriorly, becoming abruptly shorter, broader and dark brown laterally. Antenna about 1.2 mm; pedicel with short white fusiform scales mesally, dorsally and laterally; flagellomere 1 with distinct basomesal patch of white fusiform scales. Proboscis 1.95 mm; prementum dark with dark brown scales, scales on basal 0.25 semi-erect; labella yellowish brown. Maxillary palpus 2.4 mm, dark brown-scaled with three white-scaled bands: narrow band at apex of palpomere 2, wider band on apex of palpomere 3 and base of 4, and third band on apical half of palpomere 4 and all of 5. Palpomere lengths: 1, 0.125 mm; 2, 0.5 mm; 3, 0.8 mm; 4, 0.375 mm; 5, 0.235 mm. Palpal index (MPlp 4 + MPlp 5 / MPlp 3) 0.75. Subapical dark band (dark portion of MPlp 4) 0.2 mm; apical pale band (apical pale of MPlp 4 + MPlp 5) 0.325 mm (see White 1985). Ventral surface of palpus bare; MPlp 2 with erect scales, those on basal 0.5 about twice length of apical scales. Clypeus bare. Thorax: Integument pale yellowish brown, scutum and scutellum silvery pruinose, pleura silvery pruinose with 3 irregular transverse dark areas. Anterior promontory with few pale yellow erect falcate scales, mostly appressed falcate scales continue onto anterior dorsocentral area and on to prescutellar area; scutal, fossal and supraalar areas with sparse golden yellow spatulate and fusiform scales and sparse brown setae; dorsocentral and acrostichal setae brown; scutellum with row of long brown and golden-brown setae and a few pale falcate scales. Mesopostnotum and postpronotum bare. Antepronotum with few long yellowish-brown and brown setae. Pleura with pale yellow setae on: proepisternum (1), prespiracular area (4), prealar knob (7), upper (3) and lower (5) mesokatepisternum and upper mesepimeron (5). Wing: Length 3.4 mm. Pale scales yellowish. Following costal pale spots absent: basal pale, presector pale and accessory sector pale. Preapical dark spot on vein R 1 with pale interruption on one wing but not other (i. e. proximal dark scales absent). Scales of prehumeral pale spot yellowish-brown, slightly darker than other pale spots. Halter: Scabellum and pedicel pale yellow, capitellum dark with dark brown scales. Legs: Forecoxa with about 15 dark dorsal and anterior setae and few small dark spatulate scales; mid- and hindcoxae as in forecoxa but with fewer setae and scales. Trochanters with dark brown scales and pale yellow setae. Femora and tibiae mostly dark with sparse, mostly irregularly shaped speckling. Incomplete narrow pale bands on bases of midfemur and mid- and hindtibiae. Complete narrow pale bands on: apices of all tibiae; basal 0.3 of foretarsomere 1, apices of foretarsomeres 1 – 3 and base of foretarsomere 4; apices of midtarsomeres 1 – 3 and apices of hindtarsomeres 1 – 4; pale band at apex of hindtarsomere 3 0.05 mm. Pale markings of foreleg more extensive than on other legs. Midtarsomere 4 and tarsomere 5 of all legs dark. Abdomen: Very pale with golden-yellow setae dorsally, venter with golden-yellow setae changing to brown mesally, small tuft of posteromesal dark setae on sternum VII. Cerci dark brown with dark scales and setae. Male, allotype. Similar to holotype except for the usual sexual differences. Head: Flagellomere 1 with few pale scales, pedicel without scales. Proboscis slightly longer than in female (2.25 mm). Maxillary palpus: palpomeres 3 and 4 with intermixed dark and pale slender appressed fusiform scales, darker at base and distal 0.67 of palpomere 3 and sub-apically on 4; distal most part of 4 with discrete pale yellow band contrasting with dark band at base of 5; palpomere 5 with dark-scaled basal band and median dark band connected by dark ventral line, remainder pale yellow. Combined segments 4 and 5 (club) with basal narrow pale band, followed toward apex by dark band, pale band, median broad pale area, narrow dark band and pale apex. Thorax: Wing scales more sparse, roughly 0.67 of female. Genitalia (specimen MaliM 2.29): As figured in White (1985) for An. bwambae. Most distal parabasal seta (Harbach & Kitching 2005) gradually tapered and then more abruptly tapered to fine point; parabasal closest to distal parabasal broadened toward apex and then abruptly attenuated to fine point. Apex of gonostylus beyond subapical seta slightly flattened. Pupa (Figs. 2 A – C). Positions of setae essentially as illustrated for An. bwambae (White 1985). Branch numbers for the holotype of An. coluzzii in Table 1. Counts that differ of possible diagnostic use in Table 2. Cephalothorax: Evenly lightly pigmented except for darker areas beneath trumpet and mesally on metathoracic wing. Trumpet: Slightly pigmented. Length 0.46 mm; meatus 0.23 mm; pinna 0.23 mm. Abdomen: Length 1.37 mm; evenly lightly pigmented. Seta 9 - II – IV peg-like and progressively longer; seta 9 - V – VII slender, short to very long, curved inward; seta 9 - VIII with many branches or long aciculae. Seta 9 lengths: II, 0.012 mm; III, 0.02 mm; IV, 0.032 mm; V, 0.12 mm; VI, 0.15 mm; VII, 0.16 mm; VIII, 0.12 mm. Paddle: Length from base to seta 1 - Pa 0.38 mm, width 0.28 mm. Paddle lightly pigmented; midrib well developed basally becoming weak about 0.7 from base. Marginal serrations begin about 0.23 mm from base (straight line) abruptly changing to short filaments about 0.75 from base; filaments inconspicuous beyond seta 1 - Pa. Larva (Figs. 3 A – F). Positions of setae essentially as illustrated for An. bwambae (White 1985). Branch numbers for holotype of An. coluzzii in Table 3. Counts that differ of possible diagnostic use in Table 4. Head: Width 0.77 mm, length 0.59 mm. Evenly pigmented but ventrally with darkened area with irregular border roughly at level of anterior tentorial arms. Antenna: Length 0.27 mm, width at widest point 0.04 mm; seta 1 - A inserted 0.33 from base, minute, about as long as longest antennal spicule; spicules ventral, sparse, small. Distance between setae 2 - C about twice distance between setae 2 - C and 3 - C on one side. Seta 2 - C nearly as long as antenna, about 3 times longer than seta 3 - C. Seta 2 - C branches could be interpreted as aciculae. Thorax and abdomen: Positions and form of setae essentially as in White (1985) for An. bwambae. Seta 1 - I reduced palmate with about half number of leaflets as on following segments. Pecten plate: Pecten spines as follow; anterior spine longest, 3 short, 1 long, 2 short, 1 long, 2 short, 1 long, 1 short, 1 long, 1 short; members of each size class not necessarily of equal length (subequal). Denticles of small spines sparse and basal, or absent. Body region / segment; Seta An. coluzzii An. amharicus An. quadriannulatus An. bwambae An. arabiensis composite counts number (Coetzee 1987, n = (White 1985, (Ribeiro et al. 30) illustration) 1979, illustration) Cephalothorax 1 3 / 5 3 / 2 2 – 3 2 2 2 2 / 2 2 / 2 2 – 3 2 2 3 3 / 2 2 / 2 3 – 5 3 3 4 3 / 2 2 / 3 3 – 5 4 3 5 2 / 4 6 / 6 3 – 7 4 4 6 2 / 2 2 / 2 2 – 3 1 3 7 1 / 1 2 / 2 2 – 3 2 3 8 2 / 1 1 / 1 1 – 3 1? 1 9 1 / 2 1 / 1 2 – 3 1 2 10 2 / 1 2 / 2 1 – 4 1? 2 11 1 / 1 2 / 2 2 – 4 2 3 12 1 / 1 1 / 1 1 – 3 1 1 Abdomen II 0 1 / 1 1 / 1 1 1? nn 1 3 / 4 4 / 4 5 – 7 5 6 2 5 / 5 6 / 5 5 – 7 8 4 3 1 / 1 1 / 1 1 – 3 1 1 4 3 / 2 2 / 2 4 – 9 4? 5 5 3 / 2 2 / 2 3 4? 2 6 2 / 3 1 / 1 1 1 1 7 1 / 1 4 / 1 4 – 12 2 2 8? / ?? /? 0 – 3? 2 9 1 / 1 1 / 1 1 1 1 10? / ?? /? 1 – 3 1? 3 11? / ?? /? - - 1 Abdomen IV 0 1 / 1 3 / 3 1 – 2 1 nn 1 4 / 3 3 / 4 3 – 4 3 5 2 3 / 4 3 / 3 3 – 5 5 3 3 4 / 2 2 / 3 5 – 7 4 5 4 4 / 1 4 / 4 3 – 5 1? 3 5 4 / 3 1 / 1 3 – 6 4 5 6 m / 1 2 / 2 1 – 3 1 1 7 2 / 1 1 / 3 3 – 5 2 2 8 1 / 1 1 / 1 2 – 3 2? 3 9 1 / 1 1 / 1 1 1 1 10 2 / 1 1 / 1 1 – 2 1 1 11 1 / 1 1 / 1 1 1 1 14 1 / 1 1 / 1 1 1 nn Abdomen V 0 1 / 1 1 / 1 1 1 nn 1 1 / 1 1 / m 1 – 3 1 1 2 4 / 4 3 / 3 3 – 4 4 3 3 1 / 1 1 / 1 1 – 3 1 1 4 3 / 2 2 / 1 4 – 5 3 4 5 5 / 5 3 / 4 3 – 4 3 4 6 1 / 1 1 / 1 1 – 2 1 1 7 2 / 2 1 / 1 2 – 4 2 3 8 1 / 1 1 / 1 1 – 2? 2 9 1 / 1 1 / 1 1 1 1 10 1 / 1 1 / 1 1 1 1 11 1 / 1 1 / 1 1 1? 1 14 1 / 1 1 / 1 1 1 nn Not noted = nn; Not counted = nc; Missing = m; Alveolus = alv. Seta number An. coluzzii An. amharicus An. quadriannulatus An. bwambae (White (Coetzee 1987, n = 30) 1985, illustration) Range Seta number An. coluzzii An. amharicus An. quadriannulatus An. bwambae (White (Coetzee 1987, n = 30) 1985, illustration) ...... continued on the next page Seta number An. coluzzii An. amharicus An. quadriannulatus An. bwambae (White (Coetzee 1987, n = 30) 1985, illustration) Not noted = nn; Missing = m. Egg. Unknown. The descriptions given by Lounibos et al. (1990) for An. gambiae are derived from a very old colony from the type locality in The Gambia (very possibly a mixture of M and S forms) and a colony from Tanzania that is almost certainly An. gambiae (S form). Comparative analysis of these two samples showed that the Gambian colony eggs were significantly longer and wider than the Tanzanian eggs. Significant differences were also seen in the mean float length, float length per rib, anterior tubercle density and mean number of lobed tubercles (Lounibos et al. 1990). Bionomics. Anopheles coluzzii is associated with longer lasting breeding sites resulting from human activity. In the savannah, these tend to be irrigated habitats such as rice fields, reservoirs and drainage ditches. In forest areas, they tend to be urban pools, sometimes polluted. Anopheles gambiae, on the other hand, prefers habitats that are more ephemeral and rain-dependent (della Torre et al. 2005; Lehmann & Diabate 2008; Kamdem et al. 2012).