Chaetocladius guardiolei, 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 : 47-49

Chaetocladius guardiolei sp. n.

http://zoobank.org/ 1792C721-E5BC-464D-AAA1- 70637DA544E1

Material examined. Holotype. 1 male adult, France, eastern Pyrenees , Prats-De-Mollo Nature Reserve, upper basin of the Tech River, altitude 1800-2000 m a.s.l., 05.VI.2000, leg. J. Moubayed. Water siliceous, conductivity 40-50 µS/cm; pH 5.3-5.5; temperature 6-12 °C.

Paratypes. 1 male adult, as holotype except upper basin of Mantet River , Callau glacial springs and peat bogs, 05.08.2008; 2 tentatively associated male pupal exuviae, same locality and date as for holotype .

Holotype (male adult, on 1 slide) is deposited in the collections of the National Museum of Ireland, Kildare Street , Dublin 2, Ireland. The paratypes is deposited in the collection of the senior author.

Etymology. The new species is named ‘ guardiolei ’ in honour to Olivier Guardiole, who is still active as an ‘Assistant-Curator’ at Prats-De-Mollo Nature Reserve (Eastern Pyrenees) in contributing to preserving the aquatic environment and species confined to the preserved area.

Diagnostic characters

Based on the shape of the inferior volsella C. guardiolei sp. n. appears to key close to the following species: C. suecicus (Kieffer, 1916) , C. longivirgatus Stur & Spies, 2011 and C. subalpinus Rossaro, Magoga & Montagna, 2017 . However, this new species can be distinguished from related members of Chaetocladius species in having: clypeus circular; lobes of antepronotum well gaping, distinctly thicker medially; humeral pit ellipsoidal, bearing contrasting brownish granulation; tergite IX with a rounded dorsal hump; anal point triangular and sharply pointed apically, basal part cup-shaped with well-sclerotized lateral margin; virga well-developed, consisting of several long fine spines; inferior volsella well-developed, composed of 2 contrasting parts including a long finger-like expansion and a semi-circular small pouch-like lobe; gonostylus slender and thinner proximally, becoming bulbous distally; crista dorsalis absent; megaseta well-developed.

Description

Male adult

(n = 2; Figs 4 A-J)

Large. Total length 4.00- 4.10 mm. Wing length 2.35-2.45 mm; TL/WL 1.70. General colouration dark brown to blackish. Head and antenna dark brown; thorax contrasting dark brown to blackish, mesonotal stripes blackish; humeral pit brownish with contrasting dark spots; legs dark brown; membrane of wing pale brown, veins and squamal area dark brown; tergites I-VIII brownish, anal segment dark brown.

Head. Eyes bare between ommatidia; temporals of 10 inner verticals, outer verticals absent; palpomere 3 ( Fig. 4A ) with 4 sensilla clavata and 4 sensilla coeloconica; clypeus ( Fig. 4B ) nearly circular, with 7 setae in 3 rows. Antenna 1000 µm long; last flagellomere 560 µm long, slightly clubbed distally, narrowing apically with numerous curved sensilla chaetica, pre-apical seta absent; antennal groove beginning on segment 3 and reaching ultimate flagellomere; AR 1.27. Thorax. Anteprontum ( Fig. 4C ) well-developed, lobes distinctly gaping and wider medially, with 6 lateral antepronotals; acrostichals 23-25 in 1-2 rows; dorsocentrals 14- 15 in 1-2 rows; prealars 6 in 1 row; humeral pit ( Figs 4 D-E) ellipsoid, with contrasting dark spots. Wing. Brachiolum with 1 seta; membrane densely covered with coarse punctuation; number of setae on veins: R, 12; R 1, 1; remaining veins bare; squama with 9 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 4 of PII-PIII.

Hypopygium. Tergite IX and anal point (dorsal) with sternapodeme and phallapodeme as in Fig. 4F ; tergite IX broadly trapezoidal, wider at base with rectangular distal half; 16-18 dorsal setae including 10-11 located laterally on each side of the base of anal point and 6-7 close to the base of anal point; dorsal hump semi-circular, clearly visible in lateral view ( Fig. 4G ). Anal point in dorsal ( Fig. 4F ) and lateral view ( Fig. 4G ) 85 µm long, 40-45 µm maximum width at base, cup-shaped at base, distal half triangular and sharply pointed apically, lateral margin of basal part well-sclerotized, distal part (about 35 µm long) bare and hyaline; 6-7 setae present on both dorsal and lateral sides. Latero-sternite IX with 10-11 setae inserted laterally (5-6 on each side). Sternapodeme and phallapodeme ( Fig. 4F ), phallapodeme distinctly wider anteriorly. Virga ( Figs 4F, I ) well-developed, consists of 6-7 long spines about 30-40 µm long. Gonocoxite swollen basally and rounded apically; ventral margin bearing a weakly elongated lobe and 10 stout setae. Inferior volsella ( Fig. 4H ) well-developed, composed of a triangular lobe which ends in a finger-like hyaline and bare expansion; distal lobe small pouch-like, densely covered with setae. Gonostylus in dorsolateral view as in Fig. 4J , slender, thinner proximally, becoming bulbous and thicker in its distal half, posterior margin distinctly rounded; anteriorly with 2-3 rows of setae; crista dorsalis absent; megaseta about 18 µm long, well-developed.

Figures

Figure 4. Male adult of Chaetocladius guardiolei sp. n. A) palpomere 3; B) clypeus; C) lobes of antepronotum; D-E) humeral pit, two aspects; F) hypopygium, anal segment and apodemes; G) anal point and tergite IX in lateral view; H) inferior volsella; I) virga, another aspect; J) gonostylus, dorsolateral.