Chaetocladius parerai, Moubayed & Langton, 2019

Moubayed, Joel & Langton, Peter H, 2019, CHAETOCLADIUS BERYTHENSIS SP. N., C. CALLAUENSIS SP. N., C. GUARDIOLEI SP. N. AND C. PARERAI SP. N., FOUR RELICT SPECIES INHABITING GLACIAL SPRINGS AND STREAMS IN EASTERN PYRENEES AND LEBANON (DIPTERA: CHIRONOMIDAE) Abstract, CHIRONOMUS Journal of Chironomidae Research 32 (32), pp. 42-59 : 49-51

Chaetocladius parerai sp. n.

http://zoobank.org/ 7D2E5D1E-12A5-47E6-8877- C095BCEFF523

Material examined. Holotype. 1 male adult, France, eastern Pyrenees , Mantet Nature Reserve, Soques glacial springs and stream, 42° 28’ 38’’ N, 02° 18’ 26’’ E, altitude 2000 m a.s.l., 05.VIII.2008 leg. J. Moubayed. Water crystalline, conductivity 30-40 µS/cm, pH 5.5-5.7; temperature 8-10 °C, during summer, about 3-5 °C in winter and spring.

Paratypes. 1 male adult, same locality as for holotype; 3 tentatively associated male pupal exuviae, same locality and date as for holotype .

Holotype (male adult mounted on 1 slide) is deposited in the collections of the National Museum of Ireland, Kildare Street , Dublin 2, Ireland . Paratypes are deposited in the senior author’s collection.

Etymology. The new species is named ‘ parerai ’ in honour to Josep Parera, who is still active as an ‘Assistant-Curator’ at the Mantet-Py Nature Reserve (Eastern Pyrenees) in contributing to preserving the aquatic environment and species confined to the preserved area.

Diagnostic characters

C. parerai sp. n. keys close to C. guardiolei sp. n. based, in particular, on a similarly shaped inferior volsella. However, this new species is easily separated in having: lobes of antepronotum thinner at apex and gaping; humeral pit ovoid with contrasting brown granulation; tergite IX with a weakly rounded dorsal hump; anal point triangular, wider at base and parallel-sided distally, with rounded apex; virga well-developed, consists of 5 curved fine spines; inferior volsella well-developed and distinctly-contrasting, basal part long finger-like, bent downwards, caudal part a large semi-circular lobe densely covered with short setae; gonostylus slender, thin proximally, becoming much thicker distally, posterior margin with a small rounded and bare apical expansion; crista dorsalis absent; megaseta well-developed.

Description

Male adult

(n = 1, Figs 5 A-F)

Small to medium sized Chaetocladius species. Total length 3.75 mm. Wing length 2.45 mm; TL/ WL 1.53. General colouration contrasting brown yellowish to brown. Head brownish; antennae pale brown; thorax contrasting brown to dark brown, mesonotal stripes distinctly dark brown, humeral pit brownish with contrasting granulation; wing pale; legs yellow to yellowish brown; tergites I-VIII brownish, anal segment contrasting brown to dark brown.

Head. Eyes bare between ommatidia, hairs absent on inner lateral eye margin, few short setae present on outer posterior margin. 12 temporals including 9 inner and 3 outer verticals; palpomere 3 with 3 sensilla clavata and 4 sensilla coeloconica; clypeus semi-circular, bearing 12 setae in 4 rows. Antenna 1050 µm long; last flagellomere 570 µm long, slightly clubbed distally, with numerous curved sensilla chaetica, pre-apical seta absent; antennal groove beginning on segment 3 and reaching ultimate flagellomere; AR 1.19. Thorax. Anteprontum weakly-developed, lobes gaping and thinner at apex, with 6 lateral antepronotals; acrostichals 19 in 1 row; dorsocentrals 10 in 1 row; prealars in 1 row; humeral pit ovoid, with contrasting brown granulation. Wing. Brachiolum with 1 seta; membrane densely covered with coarse punctuation; number of setae on veins: R, 18; R 1, 0; R 2+3, 1; remaining veins bare; squama with 11 setae in 1 row. Legs. Tarsomeres ta 4 and ta 5 of PII sub-equal; sensilla chaetica present on: tibia and tarsomeres ta 1 -ta 5 of PI, tibia and tarsomeres ta 1 -ta 5 of PII-PIII.

Hypopygium in dorsal view as in Fig. 5C , ventral view ( Fig. 5D ) with tergite IX and anal point omitted. Tergite IX broadly rectangular, wider at base and slightly narrowing distally, posterior margin nearly straight; postero-median area with about 18 dorsal setae located around the base of anal point, 10 are inserted medially and 8 close to basal margins of anal point (4 setae on each side). Anal point in dorsal ( Fig. 5C ) and lateral view ( Fig. 5A ) about 85 µm long and 145 µm maximum width at base, with a low dorsal hump; nearly cup-shaped basally, wider at base and almost parallel-sided in its distal part, apex rounded, bare and hyaline part about 45 µm long. Latero-sternite IX with 12 setae inserted laterally (6 on each side). Sternapodeme and phallapodeme ( Fig. 5D ), phallapodeme nearly sickle-shaped. Virga ( Fig. 5C ) well-developed, consists of 5 curved spines. Gonocoxite with straight margin basally, apical part distinctly truncate; ventral margin with broad undulated lobes and bearing 10 stout setae. Inferior volsella ( Figs 5C, F ) well-developed and distinctly contrasting; anterior area acute triangular, apical part digitiform to long finger-shaped, markedly bent downwards and covered with short setae; caudal part consists of a semi-circular pouch-like lobe, densely covered with setae. Gonostylus in dorsal view ( Fig. 5E ) slender and thinner proximally, becoming thicker in its distal half; posterior margin rounded, ending with a distinct bare and rounded expansion; anterior side bearing 2 rows of setae; crista dorsalis absent; megaseta well-developed, about 15 µm long;

Taxonomic remarks

On the basis of some unusual morphological characters found in the male adult, C. berythensis sp. n. keys to the laminatus -group as emended by Moubayed-Breil (2017) for known Chaetocladius species from Europe and neighbouring geographical areas. Chaetocladius callauensis likely belong to a separate group on the basis of the atypical shape of its anal point and inferior volsella, while C. guardiolei sp. n. and C. parerai sp. n. appear to belong to the suecicus -group based, in particular due to the shape of their inferior volsella and gonostylus.

Figures

Figure 5. Male adult of Chaetocladius parerai sp. n. A) anal point and tergite IX in lateral view; B) scutellum; C) hypopygium, dorsal; D) hypopygium, ventral; E) gonostylus, dorsal; F) inferior volsella.