Bezzia blantoni Spinelli & Wirth, 1989

M, Maria & Spinelli, Gustavo R., 2009, Description of the immatures of the predaceous midge Bezzia blantoni Spinelli & Wirth (Diptera: Ceratopogonidae), Zootaxa 2295, pp. 46-54 : 47-52

Bezzia blantoni Spinelli & Wirth, 1989

(Figs. 1–29)

Bezzia blantoni Spinelli &Wirth 1989: 771 (male, female, pupa; distribution); Spinelli & Wirth, 1993: 63 (in list Argentinean species); Arnaud & Arnaud, 1996: 17; Borkent & Wirth, 1997: 125 (Catalog World species); Borkent & Spinelli, 2000: 61 (Catalog south USA species); Borkent & Spinelli, 2007: 93 (Neotropical catalog); Borkent, 2009: 157 (online Catalog).

Description of fourth instar larva (Figs. 1–12, 16). Exuviae pale yellowish. Head capsule (Figs. 1–5) elongate; apex slightly bent ventrally, setae minute, poorly visible, chaetotaxy as in Figs. 1–2; HL 0.30 mm (028–0.33, n=2), 0.41 mm (0.38–0.45, n=5); HW 0.126 mm (0.12–0.13; n=2), 0.12 mm (0.11–0.13, n=5); HR 2.62 (2.52–2.73; n=2), 3.36 (3.15–3.46, n=5); SGW 0.082 mm (0.076–0.089; n=2), 0.07 mm (0.07–0.08, n=5); SGR 1.52 (1.47–1.57; n=2), 1.64 (1.57–1.71, n=5). Labrum (Figs. 1, 3–5) longer than wide, not extending beyond hypostoma, with pair anterolateral sensilla styloconica (Fig. 5); palatum (Figs. 4–5) with 3 pairs of closely spaced sensillae, 2 trichoidea, one campaniformia (Fig. 5); palatal bar small, situated immediately posterior to messors; messors (Fig. 5) small, thin, curved, gently sclerotized, situated away from mandibles, 5 small scopae (Figs. 10, 16). Maxilla (Figs. 4–7) with blunt sensillum, maxillary palpus long, cylindrical (Fig. 6–7), with 2–3 subapical papillae; galeolacinia with stout, blunt setae (Figs. 6–7). Mandible (Figs. 4–6, 11) hooked, curved, tooth long, fosa mandibularis on ectal surface; MDL 0.05 mm (0.04–0.06, n=5). Hypostoma (Figs. 5–6) simple, finely toothed. Labium small, triangular. Epipharynx (Fig. 12) less massive, with 2 combs: ventral comb with 4–6 stout, short teeth, apical margin concave; dorsal comb with rather long teeth on posterior edge, auxiliary sclerites located near lateral arms; LAW 0.06 mm (n=3); DCW 0.03 mm (n=2). Hypopharynx (Fig. 10) long, thin, gently sclerotized, arms slender, hypopharingeal fringe (Fig. 10) present. Thoracic pigmentation uniformly pale yellowish. Caudal segment (Figs. 8–9) about 4 times longer than wide, posterior end with 6 pairs of setae, 4 of them long, stout, pale brown, the other 2 thin, short, FIGURES 1–9. Bezzia blantoni , larva; 1, head capsule, ventrolateral view; 2, head capsule, dorsolateral view; 3, head capsule, anterolateral view; 4, head capsule, anterolateral view (palatum anterior); 5, head capsule, frontal view (palatum); 6, mouthpart; 7, maxilla, lateral view; 8, insertion of setae of caudal segment; 9, caudal segment, frontal view. Head capsule chaetotaxy: j, collar pits; m, posterolateral pits; n, anterolateral pit; o, parahypostomal setae; p, posterior perifrontal setae; q, postfrontal setae; s, anterior perifrontal setae; t, prefrontal setae; u, mesolateral setae; v, posterolateral setae; w, anterolateral setae; x, paranntenal setae; y, ventral setae; z, frontal pits; collar (CO); antennae (AN); labrum (LB); hypostoma (HY); mandible (MD); palatum (PL); sensilla trichoidea (ST); sensilla styloconica (SS); sensilla campaniformia (SCa); messors (MS); maxilla ( MX); galeolacinia (GL); maxillary palpus (MP); lacinial sclerite 1 (LC1); sensilla basiconica (SB); palatal bar (PB). Larva caudal segment chaetotaxy: “o” outer setae; “i” inner setae; l1 first lateral setae.

FIGURES 10–15. Bezzia blantoni , larva; 10–12. 10, hypopharynx, dorsal view; 11, mandible, lateral view; 12, epipharynx. Pupa, 13–15.13, dorsolateral and anterodorsal tubercles; 14; ventral setae; 15, 4th abdominal segment and details. Auxillary sclerite ( AS); dorsal comb (DC); fossa mandibularis (MF); hypopharyngeal fringe (HF); ventral comb (VC); scopae (SC). Head, thoracic and 4th abdominal tubercles pupa: dorsolateral (dl) and anterodorsal (ad) tubercles; ventromedian setae (vm), ventrolateral setae (vl); abdominal tubercles: lateral anterosubmarginal tubercle (lasm); dorsal posteromarginal tubercle (dpm); dorsal anterosubmarginal tubercle (dasm); ventral posteromarginal tubercle (vpm); lateral posteromarginal tubercle (lpm); prothoracic respiratory horn (PRH); pedicel (P). Scales: 0.05 mm.

FIGURES 21–29. Bezzia blantoni , pupa; 21, entire pupa, dorsal view; 22, prothoracic respiratory horn; 23, prothoracic respiratory horn, anteroventral view; 24, head, dorsolateral view operculum; 25, dorsolateral tubercle detail; 26, dorsal tubercles; 27, 4th abdominal segment, ventral view; 28, 4th abdominal segment, lateroventral view; 29, female, caudal segment, ventral view. Anteromarginal tubercle (am); caudal segment (CS); dorsal tubercles (d); dorsolateral tubercles (dl); posterolateral proceses (PP); prothoracic respiratory horn (PRH); pedicel (P); basal sensillum (bs); operculum (O); spiracle (sp); lateral anterosubmarginal tubercle (lasm) and lateral posteromarginal tubercle (lpm); ventral posteromarginal tubercle (vpm).

brown; CSL 0.69 mm (0.62–0.73, n=4), CSW 0.12 mm (0.09–0.18, n=4), CSR 6.01 (4.00–7.10, n=4), OD 0.04 (0.03–0.06, n=5), OL 0.546 mm (0.53–0.55 mm; n=2), 0.60mm (0.57–0.66, n=4), OLODR 15.7 (10.00– 22.00, n=4).

Description of pupa (Figs. 13–15, 17–29) Length with SEM 3.35 mm. Exuviae brownish. Cephalothorax length 1.29 mm, width 0.60 mm. Operculum ( Figs. 17 , 21, 24) anterior margin rounded, grooved midway on lateral margins, midportion spiculate, with 3 pairs of tubercles: anteromarginal tubercle (am) with one single, thin, medium-sized seta, basal sensillum (bs) present; remaining two without setae; OL 0.12 mm (n=3), OW 0.24 mm (0.23–0.25, n=3), OW/OL 2.02 (1.91–2.08, n=3), anterior margin rounded, grooved midway on lateral margins, midportion spiculate, with 3 pairs of tubercles: anteromarginal tubercle (am) with one single, thin, medium-sized seta, basal sensillum (bs) present; remaining two without setae. Ventral setae (Figs. 14, 19–20) in tubercles with base rounded: 2 thin, medium-sized ventrolateral setae (vl), 2 stout, long ventromedian setae (vm). Abdominal segments with scattered small spinules. Thoracic tubercles and sensilla as follows: anterodorsal tubercle (ad) with one short, stout seta, base rounded ( Fig.18 ); dorsolateral tubercle (dl) with 2 long, thin setae, one long, one medium-sized (Figs. 13, 21, 25); 5 rounded dorsal tubercles (Figs. 21, 26), as follows: i–iv with stout, subequal, long, thin setae, v pore. Prothoracic respiratory horn (Figs. 13, 21, 22–23) PRH 0.31 mm (n=1), 0.31 mm (0.26–0.35, n=3); 4.7–5.0 times longer than wide, surface smooth, apex curved, with convoluted row of 40–50 apical spiracles (Figs. 22–23); pedicel stout, short, P 0.019 mm (n=1), 0.03 mm (0.02–0.04, n=3); P/PRH 0.06 (n=1), 0.09 (0.07–0.11, n=3) (Figs. 13, 22). Abdominal segments with scattered small spinules. Fourth abdominal segment (Figs. 15, 27–28) with 2 dorsal anterosubmarginal tubercles (dasm): i–ii base cylindrical, with medium-sized, thin seta; 3 dorsal posteromarginal tubercles (dpm): i base triangular, with 2 long, stout setae, ii pore, iii base rounded, seta minute; 2 ventral posteromarginal tubercles (vpm): i base small, short seta, ii triangular, base rounded, with 2 thin setae longer than i; 2 lateral posteromarginal tubercles (lpm), both triangular, base flattened, i with medium-sized, stout seta, ii with 2 long setae, one stout, other thin; one lateral anterosubmarginal tubercle (lasm) with base rounded, small, one long, thin seta. Caudal segment (Figs. 21, 29) 2.83 times longer than wide, dorsal surface with abundant posteriorly directed spinules; posterolateral processes slightly curved mesad in posterior end, with strong tubercles; posterolateral processes length 0.263 mm (0.25–0.27, n=3). Male CSL 0.43 mm (0.41–0.45, n=3), CSW 0.15 mm (0.14–0.16, n=3). Female CSL 0.044 mm (n=1), 0.41 mm (n=1); CSW 0.13 mm (n=1), 0.15 mm (n=1).

Distribution: Belize, Honduras, Costa Rica, Puerto Rico, Argentina (Buenos Aires and Corrientes provinces).

Specimens examined. Argentina, Buenos Aires prov., isla Martín García, Arenal Chico, 20.vii.2006, M. Ronderos – F. Díaz col., 4 larvae, 2 pupae; same data except 14.ix.2006, 1 pupa, same data except 11.x.2006, 1 larva, 1 pupa.

For SEM: same data, 3 larvae, 1 female pupa.

Physicochemical variables of the water in the pond: temperature: 21.25 (16.0–23.6 °C); conductivity: 19 µs; total disolved solids (TSD): 13 mg /l; PH: 5.59 (5.54–5.68)

Figures

FIGURES 16 – 20. Bezzia blantoni, larva; 16, scopae; 17 – 20, Pupa, 17, operculum, dorsal view; 18, anterodorsal tubercle (ad), lateral view; 19, ventral setae; 20, detail of ventromedian setae. anteromarginal tubercle (am); anterodorsal tubercle (ad); basal sensillum (bs); ventromedian setae (vm). Scale 0.05 mm