Allocladius globosus, Andersen & Saether & Mendes, 2010

Andersen, Trond, Saether, Ole A. & Mendes, Humberto F., 2010, Neotropical Allocladius Kieffer, 1913 and Pseudosmittia Edwards, 1932 (Diptera: Chironomidae) 2472, Zootaxa 2472 (1), pp. 1-77 : 11-12

Allocladius globosus sp. n.

( Figs 20–26 )

Type material. Holotype male, CHILE: Región V, Río Aconcagua , West of Las Vizcachas, 32º51.391'S, 70º 28.668'W, 1.096 m a.s.l., 12.xi.1998, hand net, T. Andersen ( ZMBN Type No. 423) . Paratypes: 1 male, Región VI, Pichilemu , 3 km West of Alcones, 34º23.486'S, 71º46.807'W, 220 m a.s.l., 17.xi.1998, hand net, T. Andersen ( ZMBN) . 1 male, Región XI, Río Blanco , 20 km South of Puerto Aisén, 13.i.1996, hand net, T. Andersen ( ZMBN) .

Diagnostic characters. The presence of circular single pars ventralis about as long as wide and with setae together with the absence of a posterior lobe of the inferior volsella will separate the species from other species with pars ventralis.

Etymology. From Latin, globosus , spherical, referring to the round pars ventralis.

Male (n = 3, except when otherwise stated). Total length 1.83–2.24 mm. Wing length 1.07–1.26 mm. Total length / wing length 1.67–1.78. Wing length / length of profemur 2.89–3.00.

Coloration. Fully brown.

Head. AR 0.88–1.09. Ultimate flagellomere 308–409 µm long. Temporal setae 4–5, consisting of 1–2 weak inner verticals, 2–4 strong outer verticals, and 0–1 postorbital. Clypeus with 4–7 setae. Tentorium, stipes, and cibarial pump as in Figure 20 . Tentorium 79–113 µm long, 26–30 µm wide. Stipes 109–128 µm long, 34–41 µm wide. Palpomere ( Fig. 21 ) lengths (in µm): 23–30, 30–45, 68–83, 60–75, 86–105. Third palpomere with 1 lanceolate sensilla clavata, 15 µm long.

Thorax ( Fig. 22 ). Median antepronotal lobes comparatively well developed, antepronotum with 1–2 lateral setae. Dorsocentrals 7–8, acrostichals about 10 (1), prealars 4, supraalar 1. Scutellum with 4 setae.

Wing ( Fig. 23 ). VR 1.30–1.40. Anal lobe distinct, slightly projecting. Costal extension absent, but indication of 110–130 µm long false vein. R 4+5 ending slightly proximal to apex of M 3+4; Cu 1 sinuous. Brachiolum with 1 seta, R with 2 setae, other veins bare.

Legs. Spur of fore tibia 38 µm long, spurs of mid tibia 23–26 µm and 19 (2) µm long, of hind tibia 38–41 µm and 19 µm long. Width at apex of fore- and mid tibia 26–28 µm, of hind tibia 34–38 µm. Comb of 11–12 setae, longest 26–30 µm long, shortest 15–29 µm long. Length and proportions of legs as in Table 4.

Hypopygium ( Figs 24–25 ). Anal point 26–41 µm long, including 15 µm long sclerotized basal part with 7–10 setae and 11–26 µm long bare, hyaline distal part. Tergite IX with 9–10 setae in addition to those on anal point. Laterosternite IX with 2–5 setae. Phallapodeme 53–56 µm long. Transverse sternapodeme 41–53 µm long, with weak oral projections. Virga 11–15 µm long, thumbnail-like. Pars ventralis ( Fig. 26 ) single, 45–60 µm long, 45–56 µm wide. Gonocoxite 131–143 µm long. Superior volsella present as dorsal swelling of inner margin of gonocoxite, reaching to 0.42–0.50 gonocoxite length. Inferior volsella well developed, reaching to 0.63–0.69 gonocoxite length; no apparent posterior lobe. Gonostylus 53–60 µm long; megaseta 11–13 µm long. HR 2.38–2.50. HV 3.38–3.73.

Distribution and biology. The species is known from southern and central Chile where it has been netted on the banks of streams and rivers. The altitude range is from about 200 to 1.000 m a.s.l.

Figures

FIGURES 20–26. Allocladius globosus sp. n., male. 20—tentorium, stipes, and cibarial pump; 21—palp; 22—thorax; 23—wing; 24—hypopygium, dorsal aspect; 25—hypopygium with anal point and tergite IX removed, dorsal aspect to the left, ventral aspect to the right; 26—pars ventralis.