Psychoda glamocensis, Wagner & Rada, 2020

Wagner, Rüdiger & Rada, Tonći, 2020, Moth flies (Diptera, Psychodidae) living in the dark of caves in the Dinaric Karst, Zootaxa 4845 (2), pp. 275-282 : 278-281

Psychoda glamocensis sp. nov.

( Figs 10–26 )

Etymology. Named after Glamoč, a town and municipality located in Canton 10 of the Federation of Bosnia and Herzegovina.

Diagnosis. Psychoda glamocensis sp. nov. is distinguished from its congeners by the reduced eyebridge, gonostyli with a very long seta in the basal third and the subtriangular aedeagus with the axe-shaped sclerite.

Type material. Holotype 1♂, Bosnia and Hercegovina, Golubnjača kod Skucana, Skucani, Glamoč (43˚58’31.9’’N/016˚54’43.6’’E, 1.005 m a.s.l.). July 2018; paratypes, 8♂, 1♀ same as holotype; 8♂, 2♀, (paratypes), Croatia, Golubinka pod Kraljevcom, Radošić (43˚35’45.2’’ N/ 016˚20’32’’E, 233 m asl.) 15 February 2019; 49♂, 32♀, (paratypes), Croatia, Radošić , Golubinka pod Kraljevkom Pit, 8 October 2018.

Further material. 36♂, 5♀, Croatia, Ercegovici, Rušića jama, 6 April 2019 ; 49♂, 8♀, Croatia Trilj, Bakuša 5 June 2019 ; 1♂ Croatia, Voštane, Golubinka u Ljutu , 24 February 2019 ; 42♂, 2♀, Croatia, Labin Dalmatinski, Velika Zečica Donji , 13 March 2019 ; 5♂, 2♀, Croatia, Zelovo, Elezova jama, 19 May 2019 ; 12♂, 5♀, Croatia, Unešić, Dželalijina Golubinka , 10 March 2019 ; all leg. T. Rada ; 1♂ Austria, Lower Austria, Lunz am See, emergence trap at Schreierbach , 12 October 1972 leg. Malicky ; 1 st report from Austria (in collection RW).

Holotype and paratypes and the mentioned further material are deposited in the Natural History Museum & Zoo, Split, Croatia. Three paratypes (2♂, 1♀) remain in the collection of the senior author .

Description. Male: Eyes reniform, eyebridge with 2 or 3 rows of irregularly arranged facets, interocular suture wide U-shaped, distance between the eyes 2–2.5 facet diameter (figs 10–12). Antenna (fig. 14–15) with scape, pedicel and 13 flagellomeres; scape short, wider than long, pedicel spherical, flagellomeres bottle-shaped, with remarkably long necks, flagellomeres 1–10 with a pair of Y-shaped ascoids about as long as a flagellomere, apical flagellomeres 11–13 reduced in size, 12 and 13 with a subapical lobe and a short stiff bristle. Relative length of scape, pedicel and flagellomeres: 49-28-88-83-82-81-77-76-72-66-69-57-25-15-12; absolute length: 0.13-0.07- 0.23-0.22-0.22-0.21-0.20-0.20-0.19-0.17-0.18-0.15-0.07-0.04- 0.03 mm. Four palpus segments, terminal segment flexible; relative length: 49-49-46-55; absolute length: 0.13-0.13- 0.12-0.14 mm. Mouth parts with 4 acute apical teeth (fig. 16).

Wing length 3.1 mm, width 1.1 mm. C basally with 2 swellings; Sc short, a setose area, terminates in wing. R 1 terminates in the distal half of the wing; division of Rs with fork R 2 / R 3+4 at level of Sc tip. R 5 terminates short behind wing tip; radial and medial fork complete; medial fork basal of radial fork. CuA basally broader; in the basal part of the wing all veins are broken, here is fold that enables specimens to hold the wing in roof shape at rest. Cross veins not detected. Thorax without specific features.

Abdomen with 8 segments, genitalia (figs 22–26) inverted; hypandrium broad, slightly broader in the midst. Gonocoxites short tubular about 1.5 times longer than wide, probably without setae. Dorsal parameral bridge (fig. 25) of gonocoxites thin in the middle, laterally widened; ventral bridge of parameres are blade shaped sclerites with sharp bent tips that do not meet in the middle. Gonostyli elongate triangular. almost straight; behind the basal swelling with a remarkably long and strong seta, about as long as the gonostylus. Epandrium (fig. 23) with 1 median foramen; edges roundish. basal edge deeply curved, apical edge almost straight. Subepandial plate increasingly wide apically with a broad median connection to the proctiger and to lateral plates connecting with the bases of the basally swollen epandrial appendages. Proctiger not clearly discernable; the epandrial processes clearly longer than the epandrium, strongly bent, apically with a sharp tip beside the basis of the retinaculum.

Aedeagus consists of an asymmetric bilobed basal sclerite, lobes apically curved inwards; the distal sclerite is shorter than the basal sclerite, asymmetric, tomahawk shaped.

Female: in most respects similar to male but poorly preserved. Differences are minor in the antenna and wing venation. Eye bridge fig. 13, mouth parts fig. 17 and 18.

Relative length of antennal articles: 34-24-57-51-53-48-52-48-42-; absolute length: 0,09-0,06-0,15-0,13-0,14- 0,13-0,14-0,13-0,11- mm, apical segments missing. Four palpus segments, terminal segment flexible; relative length: 30-28-28-34; absolute length: 0.08-0.07- 0.07-0.09 mm. Mouth parts with 4 acute apical teeth.

Wing length approximately 2.20 mm.

Genitalia (figs. 20, 21) with a bilobed subgenital plate with an elongate tubular structure, laterally accompanied by a pair of sclerites that appear to be superficially similar to the parameral complex of the male. Basally is a complicatedly folded sclerite of probably specific shape.

DNA Barcoding. The availability of a DNA barcode permits comparison with other Psychoda species. The two sequences (ZFMK-TIS-2617210 consensus sequence (reversed), ZFMK-TIS-2617212 consensus sequence (reversed)) indicate the closest relation with specimens of Psychoda alticola Vaillant 1973 , from the Norwegian Finnmark ( Kvifte & Andersen 2012). Sequences from Alpine specimens are presently not available.

Remarks. The most striking feature of both new species is the reduction of the eyes probably due to life in caves The number of facets and facet rows varies extremely and differs even between specimens. In Psychoda s. lat. species the eye bridge usually consists of 4 parallel regular rows but in Ps. glamocensis sp. nov. the number of facet rows is reduced to mostly 2, with irregular arranged facets. Eyes are widely separate in both sexes so that the shape of the eyebridge varies between individuals. All specimens were collected deep in the caves, at Golubnjača kod Skucana at a depth of 30 m at permanent darkness, and at Golubinka pod Kraljevcom 25m deep at semidarkness. The malformation of palpus segments in several specimens is probably due to in-breeding in small populations in different caves. Number of teeth on mouthparts is as well variable and differs between specimens.

This indicates that populations live for a long time in the caves. Long term low temperatures and enduring darkness are probable preconditions to develop morphological changes of the eyes and palpus segments. The antenna appears longer compared with the head diameter and the long seta on the gonostyli are further indications that antennae and setae may play major roles as tactile instruments to detect and locate conspecifics or avoid predators.

The sex ratio in collections from all localities is unusual for Psychoda species; light trap collections often contain exclusively females. However, in Golubnjača kod Skucana cave 90%, in the Golubinka pod Kraljevcom cave 80%, and in Golubinka pod Kraljevkom cave 60% males were collected. The first two caves give shelter to wild pigeon ( Columba livia Gmelin ); probably the larvae of Psychoda glamocensis sp. nov. feed on their feces and remains; bats that are usually further inhabitants of caves may provide further organic material.

The additional male from Austria was found as undetermined but close to P. alticola in the collection of the senior author; identification was finally easy based on the reduced eye bridge and male genitalia. The locality Schreierbach is a permanent cold stream (probably a very large rheocrene) with constant water temperature of about 8°C all year round. Here P. glamocensis was collected together with specimens that are doubtless P. alticola ; both species seem to prefer cold conditions that occur in the Alps at higher elevation, but as well in cold springs, and caves at lower altitudes.

Figures

FIGURES 10–21. Psychoda glamocensis. 10. Eyebridge of male holotype. 11–12. Eyebridges of male paratypes. 13. Same of female paratype. 14. Flagellomeres 10–13. 15. 2nd flagellomere with ascoid. 16. Male mouth parts.17–18. Female mouth parts. 19. Wing. 20. Female subgenital plate. 21. Internal genital sclerites, female. Scale: 1.0 mm (19), 0.1 mm (10–15, 20–21), 0.05 mm (16–18).

FIGURES 22–26. Psychoda glamocensis. 22. Hypandrium, gonostyli and aedeagus, holotype. 23. Epandrium, subepandrial plate and bases of epandrial processes. 24. Right epandrial process with retinaculum. 25. Left gonocoxite, parameral bridges and position of distiphallus sclerite, holotype. 26. Basiphallus and distiphallus sclerites and periaedeagal membrane. Scale: 0.1 mm (22–26).