Allocladius globosus Andersen, Saether & Mendes

Mauad, Melina, Siri, Augusto & Donato, Mariano, 2013, New species of Pseudosmittia Edwards, 1932 and new records of Allocladius Kieffer, 1913 (Diptera: Chironomidae, Orthocladiinae) from South America, Zootaxa 3694 (5), pp. 445-460 : 455-456

Allocladius globosus Andersen, Saether & Mendes

Allocladius globosus Andersen, Saether and Mendes, 2010: 11 ; Ferrington & Saether (2011: 97).

Material examined. ARGENTINA: 2 males, Buenos Aires, Sierra de la Ventana, Aº Cueva del toro, spring, 38º 01' 30.2'' S, 62º 01' 55.4" W, 932 m a.s.l., 21.v.2012, sweep net, M. Donato, A. Siri and F. Spacessi; 3 males, Río Negro, Río Ñirihuau, near Bariloche´s airport, 41º 09' 54.6" S, 71º 07' 54.9" W, 848 m a.s.l., 18.iv.2012, sweep net, M. Donato and A. Siri.

Male (n = 5, except when otherwise stated). The following measurements are different from the original description. Total length 2.13–3.1 mm. Wing length maximum value 1.93 mm. Total length/wing length minimum value 1.61. Wing length/length of profemur 2.45–3.21 (4).

Head. Maximum value for AR 1.31. Maximum length of ultimate flagellomere 550. Temporal setae 8–9, consisting of 0–3 weak inner verticals, 0–4 strong outer verticals, and 1–4 postorbital. Clypeus with 6–14 setae. Tentorium 113–156 long, 25–38 wide. Stipes 109–166 long, 8–15 wide. Palpomere lengths (1–5): 16–34, 35–53, 68–103, 73–105, 85–143.

Thorax. Dorsocentrals 7–13, acrostichals 6–7, prealars 3–4. Scutellum 6–7 (4) setae. Wing. VR minimum value 1.15. R with 2–4 setae, other veins bare.

Legs. Spur of front tibia 38–53 (4) long, spurs of midd tibia 19–23 (2) and 15–18 (3) long, of hind tibia 40–53 (4) and 15–20 (4) long. Width at apex of front tibia 26–48, of mid tibia 25–38, of hind tibia 33–58. Comb of 15–17 setae. Length and proportions of legs as in Table 5 .

Hypopygium. Anal point maximum length 45 (3), including 20–28 long sclerotized basal part with 4–5 setae and 10–20 long bare, hyaline distal part. Tergite IX with 13 setae in addition to those on anal point. Laterosternite IX with 2–5 setae. Phallapodeme 35–49 long. Transverse sternapodeme 60–83 long, with weak oral projections. Virga minimum length 6. Gonocoxite maximum length 210. Inferior volsella reaching to 0.43–0.48 gonocoxite length. Gonostylus maximum length 90; megaseta minimum length 9. HR minimum value 2.23. HV minimum value 3.29.

Remarks. The new records of A. globosus extend its distribution from Chile to Argentina ( Fig. 13 ). The specimens collected in Ñirihuau river show significant differences in several characters from the specimens collected in the spring of Cueva del toro stream. The characters total length, number of clypeal setae, length and width of tentorium, length and width of stipes, length of ultimate flagellomere, AR, wing length, wing length/ length of profemur and gonocoxite length of the latter specimens are higher than those of the former specimens.

The Ventania hill system is located SW of Buenos Aires province, with its highest altitude of 1243 m a.s.l. As a consequence of its orogenetic origin and geographic position, Ventania was considered as "an island of biodiversity" since wildlife from the Brazilian region from the north and the Patagonia from the south could occur (Ringuelet, 1961).

The Ventania system is part of the peripampasic orogenic arc defined by Frenguelli (1950) together with other orogenetic systems from Argentina and shows disjunct biogeographic distributions of several and different groups of taxa (Ringuelet, 1961). The occurrence of A. globosus in this system is an example of this particular distributional pattern and this new record reinforces this pattern also found in other Chironomidae species ( Siri & Donato, 2012).

Figures

FIGURE 13. Map showing the new records of Allocladius globosus and A. quadrus. A. globosus: square, known records; triangle, new records. A. quadrus: star, known records; circle, new records.

Tables

TABLE 5. Lengths (in µm) and proportions of legs of Allocladius globosus (male) (n = 5, except when otherwise stated). For abbreviation explanations see Table 1.

fe	ti	ta1	ta2	ta3
P1 290–550 (4)	310–770	170–370	90–260	70–190
P2 300–780	300–770	135–350	80–190	55–145
P3 330–840	330–850	170–450	90–250	70–200
ta4	ta5	LR	BV	SV
P1 40–130	35–85	0.39–0.55	3.28–3.77 (4)	3.53–4.83 (4)
P2 40–100	30–80	0.39–0.45	3.36–3.87	4.43–4.96
P3 40–110	35–90	0.49–0.54	3.19–3.54	3.64–3.97