Chalarus chairensis, Ramos-Pastrana & Marques & Rafael, 2023

Ramos-Pastrana, Yardany, Marques, Dayse Willkenia A. & Rafael, José Albertino, 2023, Chalarus (Diptera: Pipunculidae) of Colombia, with description of two new species and an updated key to males of the Neotropical species, Acta Entomologica Musei Nationalis Pragae 63 (2), pp. 383-395 : 388

Chalarus chairensis sp. nov.

( Figs 23–32 , 55 )

Type locality. Colombia: Caquetá, Cartagena del Chaira, Vereda Tigrera Alta.

Type material ( 1 J). HOLOTYඉE: J, COLOMBIA, Caquetá, Cartagena del Chaira, / Vda.[Vereda] Tigrera Alta, Fca.[Finca] Las Palmeras , / 01º17’5.2’’N / 74º49’1.2’’W, 235 m [eters], / 23– Nov. [xi] –07– Dic. [ XII].2016, / trampa Malaise en dosel del bosque, Y. Ramos-Pastrana leg. ( LEUA –00000049759) (photographed specimen). Holotype with left wing mounted on microslide with Canada balsam. Left antenna and terminalia placed in a microvial with glycerin, both pinned along with the specimen.

Diagnosis. Male. Postpronotal lobe yellowish brown, brown pruinose. Both surstyli with one lobe medially, inward directed, and apices downward directed; left surstylus with apex slightly rounded and outer margin curved; right surstylus with apex slightly acute and outer margin sinuous; both surstyli with apices clearly truncated, left surstylus slightly longer than right, without sinus at junction with epandrium when seen in lateral view. Right gonopod slightly thinner and with apex more acute than left one. Tip of distiphallus long, with two asymmetrical phallic processes of equal length but one twice as wide as the other. Phallus trifid, all ejaculatory ducts situated at apex; lateral ejaculatory ducts with inner margins straight, forming angle of approximately 110º in dorsal view.

Description. Male (holotype). Body length 2.2 mm. Head ( Figs 23–24 ). Frons: upper 3/4 dark brown, dark brown pruinose, lower 1/4 gray-brown pruinose. Occiput dark brown. Pedicel with two setae dorsally and two ventrally; postpedicel lost. Thorax ( Figs 24–25 ). Postpronotal lobe yellowish brown, brown pruinose. Scutum brown, brown pruinose. Notopleuron and scutellum concolorous with scutum. Mesopleuron light brown, brown pruinose. Mediotergite concolorous with mesopleuron. Wing ( Fig. 26 ). Length 2.3 mm. LW/MWW = 3.1; LTC/LFC = 9. Membrane brown infuscated. Halter light brown. Legs ( Fig. 23 ). Entirely brown, except tarsomeres 1–5 dark brown; pulvilli light brown. Abdomen ( Figs 23–24, 27 ). Brown, gray-brown pruinose, with long setae laterally and short scattered setae dorsally; tergite 1 light brown basally, brown posterolaterally; tergite 1–5 with transverse bands brown pruinose; tergite 6 clearly longer than tergite 5; syntergosternite 8 with long apical setae ( Figs 27–28 ). Terminalia ( Figs 28–32 ). Epandrium and surstyli brown ( Fig. 28 ). Surstyli ( Figs 28–30 ) subsymmetrical and setose, with apices directed downward; both surstyli with one lobe medially on inner margins; left surstylus with apex slightly rounded and outer margin curved; right surstylus with apex slightly acute and outer margin sinuous ( Fig. 28 ); both surstyli with apices clearly truncated; left surstylus slightly longer than right, without sinus at junction with epandrium in lateral view ( Figs 29–30 ). Gonopods subsymmetrical; right gonopod slightly thinner and with apex more acute than left one ( Figs 29–30 ). Tip of distiphallus long, with two asymmetrical phallic processes, equal in length but one twice as wide as the other ( Fig. 31A ). Ejaculatory apodeme pin-shaped ( Fig. 32 ). Phallus trifid, all ejaculatory ducts situated at apex in lateral and dorsal view ( Figs 31A–B ).

Female. Unknown.

Etymology. The specific epithet refers to the type locality, Cartagena del Chaira; adjective.

Habitat. The specimen was collected in preserved areas of tropical rainforest in the Colombian Amazon, Department of Caquetá.

Geographical distribution. Colombia (Caquetá) ( Fig. 55 ). Taxonomic notes. Chalarus chairensis sp. nov. runs to C. absonus Rafael, 1990 in the couplet 8 of the key presented by RAFAEL (1990). It differs from C. absonus in having the postpronotal lobe yellowish brown (versus postpronotal lobe brown); legs entirely brown, except tarsomeres 1–5 dark brown ( Fig. 23 ) (versus legs entirely dark brown, brown pruinose); the other distinguishing characters can be seen in the key below.

Figures

Figs 23–32. Chalarus chairensis sp. nov. (LEUA–00000049759). Holotype, male. 23 – habitus, left lateral view; 24 – habitus, dorsal view; 25 – thorax, dorsal view; 26 – wing; 27 – abdomen, dorsal view; 28 – terminalia, dorsal view; 29 – left surstylus and gonopod, lateral view; 30 – right surstylus and gonopod, lateral view; 31a – phallic guide, subapical processes and phallus, right lateral view, 31b – phallus dorsal view; 32 – ejaculatory apodeme.

Fig. 55. Geographical records of Chalarus species in Colombia. Chalarus absonus Rafael, 1990, C. boyacensis sp. nov., C. chairensis sp. nov., C. connexus Rafael, 1988, and C. delicatus Rafael, 1990.