Research Article |
Corresponding author: Rob Felix ( robfelix1@gmail.com ) Corresponding author: Josip Skejo ( skejo.josip@gmail.com ) Academic editor: Tony Robillard
© 2020 Rob Felix, Klaus-Gerhard Heller, Baudewijn Odé, Fran Rebrina, Josip Skejo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Felix R, Heller K-G, Odé B, Rebrina F, Skejo J (2020) Island mysteries in the spotlight: Barbitistes kaltenbachi and Rhacocleis buchichii, the only bush-cricket species endemic to Croatia (Orthoptera, Tettigoniidae). ZooKeys 936: 25-60. https://doi.org/10.3897/zookeys.936.51599
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Hvar Saw Bush-cricket Barbitistes kaltenbachi Harz, 1965 (Phaneropterinae: Barbitistini) and Lesina Bush-cricket Rhacocleis buchichii Brunner von Wattenwyl in
Adriatic, Barbitistini, bioacoustics, Biokovo, Dalmatia, duet, ecology, Endangered, flightless, Hvar, IUCN Red List, Platycleidini, systematics, Vis Island, Vulnerable
Despite two centuries of research on Orthoptera in Croatia (
Both species were originally described from the Island of Hvar (Lesina in Italian), one of Croatia’s Adriatic islands, belonging to the Central Dalmatian archipelago. Until now Barbitistes kaltenbachi has been regarded as a Hvar-endemic, while Rhacocleis buchichii has been found on other Dalmatian islands (
Since so little has been published about Barbitistes kaltenbachi and Rhacocleis buchichii, the authors of the current paper felt the need to present a comprehensive overview of the information available. This paper is written around RF’s finding of both species on the Island of Vis, well outside their formerly known distribution areas (briefly mentioned in
The Central Dalmatian islands (Fig.
Specimens were identified using
Specimens mentioned in this paper are deposited in the following collections:
KGHC Klaus-Gerhard Heller Collection
NBC Naturalis Biodiversity Center, Leiden, the Netherlands
RFPC Rob Felix Collection, Nijmegen, the Netherlands
ZSZJS Natural History Museum Split: Josip Skejo Collection, Split, Croatia
Body length (from the frons to the tip of the abdomen), pronotum length in dorsal view, hind femora length, and ovipositor length (in females), were measured with a calliper of 0.1 mm precision.
Male song (including the male-versus-male-interaction duets) was usually recorded in the evening, using a Sony WM-D3 cassette recorder and a SONY TCD-D7 DAT recorder with microphones Uher M 645 (Uher, Munich, Germany) and Sony ECM-121 (Sony, Tokyo, Japan). For the interactions (20 min duet recordings; 6 males) two males were placed separately, each in a plastic tube (Drosophila tube 28.5 × 95 mm, Biosigma, Cona (VE), Italy), standing side by side and each with a microphone placed inside (or on top of) the tube. Both microphones typically picked up both male sounds, but with quantifiable differences in amplitude. The output of each microphone was registered as a track of a stereo recording. After digitising the songs on a computer (sampling rate 44.1 kHz), oscillograms (after high pass filtering, typically around 1 kHz) and sound analyses were made using the following software: Turbolab (TL 4.0, Stemmer, Puchheim, Germany), Amadeus (Amadeus II, Martin Hairer, http://www.hairersoft.com), Audacity (Audacity 2.1.0; http://audacity.sourceforge.net) and Canary (Canary 1.2.4; Cornell Laboratory of Ornithology) on Apple. Due to the recorders’ restricted frequency response, data on frequency were not evaluated. Each data point for the time pattern is based on not less than 20 independent measurements (except series data), given as mean ± standard deviation (SD) and coefficient of variance (CV) (see Suppl. material
Two sound recordings of two different individuals of this species have been made by Roy Kleukers (see Material examined under Rhacocleis buchichii), using a DCC-recorder (Philips DCC175) with a Shure Prologic condenser microphone. Sound recordings have been made in simple studio conditions at night, at 26–27 °C. Although the recordings are digital, some frequencies inaudible to humans were automatically removed before digitisation. Also, frequencies above ca. 20kHz are missing completely. The sound recordings are therefore not very useful for the analysis of frequencies. Yet, they are useful for temporal analysis of the song.
Temporal characters have been measured for both sound recordings using Wavelab 10 software (www.steinberg.net). A high pass filtering at 500Hz using phonetic software Praat 6.0.39 (www.praat.org) preceded the preparation of oscillograms for the Pitve specimen only.
Bioacoustic data of other Rhacocleis species has been derived from
Syllable. sound produced during one cycle of wing movements. In Barbitistes only pulse-like closing hemi-syllables are known (
Data from the previous IUCN assessments for B. kaltenbachi (
Subfamily Phaneropterinae Burmeister, 1838
Tribe Barbitistini Jacobson, 1905
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi
Harz, 1965:
Barbitistes kaltenbachi:
Barbitistes kaltenbachi:
Barbitistes kaltenbachi
Harz, 1965:
Type specimens of B. kaltenbachi are deposited in
Croatia • 2♂, 1♀; Vis Is., Mount Hum, Crikvica Sv. Duha; alt. 545 m a.s.l.; 43°02.13'N, 16°06.92'E; 21 Jul. 2011; R. Felix leg.; RFPC • 4♂, 2♀; Hvar Is., near Bogomolje, Likova Glava; 30 May 2006; M. & K.-G. Heller leg.; KGHC CH6738, CH6739, CH6740, CH6751, CH6752, CH6754 • 1♂; same data as for preceding; NBC CH6735 • 3♂, 1♀; Hvar Is., Sucuraj; 30 May 2006; M. & K.-G. Heller leg.; KGHC CH6736, CH6737, CH6755, CH6759.
Hvar Saw Bush-cricket was found on 20 and 21 July 2011, near the Chapel of St. Spirit (Crikvica Sv. Duha) at Mount Hum, in the southwestern corner of Vis (43°02.13'N, 16°06.92'E, 545 m a.s.l.) (Figs
Distribution of the only known endemic bush-crickets (Tettigoniidae) of Croatia: Barbitistes kaltenbachi (localities 1–3) and Rhacocleis buchichii (localities 1, 4–14, ?) 1 new records from Vis Is., Mt. Hum (present paper) 2 Hvar Is., Likova Glava, Bogomolje (present paper;
Photos of a syntype male of Barbitistes kaltenbachi by G. Puskás taken from OSF (
The right tegmen of the female has several rows of stridulatory pegs, in resting position covered by the upper left tegmen. To produce sound, the pegs are probably contacted by the slightly enhanced inner edge or a sclerotised vein on the lower side of the left tegmen.
All known records of B. kaltenbachi are shown on the map in Fig.
Known records of Barbitistes kaltenbachi with data on the sites and collection events. The #map correspond with the numbers in Fig.
# map | Specimens | Location | Date of collection | Coll. | Reference |
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1 | 2♂, 2♀ | Vis Is., Mt. Hum, Crikvica Sv. Duha, 43°02.13'N, 16°06.92'E, 545 m a.s.l. | 20, 21 Jul. 2011 | RFPC | This study |
2 | 5♂, 2♀ | Hvar Is., Bogomolje, Likova Glava | 30 May 2006 | KGHC |
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3 | 3♂, 1♀ | Hvar Is., near Sućuraj | 30 May 2006 | KGHC |
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No published data on the habitat of B. kaltenbachi are available. On Vis Is. the species has been found on bushes and small trees of Holm Oak, in maquis intercepted with scattered patches of grassy vegetation and bare limestone rock (Fig.
Collecting sites on Vis Is. and Hvar Is., Croatia A Vis Is., Mount Hum, St. Spirit Chapel (21 Jul. 2011). This locality is inhabited by both Barbitistes kaltenbachi and Rhacocleis buchichii. The vegetation is rich in Holm Oak bushes (Quercus ilex) (photograph R. Felix) B Hvar Is., Likova Glava, Bogomolje (30 May 2006), the habitat of B. kaltenbachi (photograph K.-G. Heller).
The male calling song consists of short (up to ca. 10 ms), pulse-like syllables without clearly recognisable impulses (tooth impacts). Syllables are arranged in a stereotyped pattern. One loud syllable, the trigger syllable, assumed to be the marker for female response (
Bioacoustic data of Barbitistes kaltenbachi A oscillogram showing bioacoustics terminology used in our study B, C details of the calling song (sections of 8 seconds) B second male starting in synchrony C second male starting anti-phasic, first male switching to synchrony D male song with extra syllables (red arrows, see text) E difference in starting time between the trigger syllables of two duetting males, always referring to a focal male; different colours indicate different male combinations; intervals in the lines mark duet pauses.
Males of Barbitistes kaltenbachi can be distinguished from its Croatian congeners, B. ocskayi Charpentier in Ocskay et al., 1850, B. serricauda (Fabricius, 1794), and B. yersini Brunner von Wattenwyl, 1878 (Fig.
All Barbitistes species occurring in Croatia A B. kaltenbachi (Croatia, Hvar, 30 May 2006) B B. serricauda (Austria, Obir near Klagenfurt, 13 August 1980) C Male B. ocskayi (Montenegro, Lovćen pass above Kotor, 26 July 1982) D Female B. ocskayi (same locality as male) E Male B. yersini (Croatia, Grabovača, 7 Aug. 2018) F Female B. yersini (Croatia, Sniježnica, 20 Aug. 2018) (A–D photos K.-G. Heller E, F photos F. Rebrina).
Male cerci of all members of the genus Barbitistes A–E, G, H left cercus F right cercus flipped vertically A B. kaltenbachi B B. constrictus C B. alpinus D B. fischeri E B. serricauda F B. vicetinus G B. ocskayi H B. yersini (photographs K.-G. Heller). Based on cercal morphology, B. kaltenbachi is most similar to B. constrictus.
The song of B. kaltenbachi differs distinctly from the songs of all other Barbitistes-species in the temporal pattern of the syllables (Fig.
In Croatia, four species of Barbitistes occur, namely Barbitistes kaltenbachi, B. ocskayi, B. serricauda, and B. yersini (
1 | Cercus thickened in the middle, proximal half in an abrupt but obtuse angle with the distal part, giving the cercus an elbow-like appearance. Distal half angularly sinuous (Fig. |
Barbitistes kaltenbachi Harz, 1965 |
– | Cercus not thickened in the middle, but gradually narrowing from base to apex. Distal part slightly and smoothly sinuous | 2 |
2 | Subgenital plate with a nose-like projection, visible in lateral view. [Dubrovnik region; Istria, Kvarner with adjacent islands] | Barbitistes ocskayi Charpentier in Ocskay et al., 1850 |
– | Subgenital plate without a nose-like projection, almost flat | 3 |
3 | Cercus halfway strongly incurved, with proximal and distal halves in an almost right angle (Fig. |
Barbitistes yersini Brunner von Wattenwyl, 1878 |
– | Cerci gradually curved (Fig. |
Barbitistes serricauda (Fabricius, 1794) |
Current status. Near Threatened in Europe and EU28 (
Area of occupancy (AOO): calculated from the known data (ca.) 12 km2, maximal estimation 72–80 km2.
Extent of occurrence (EOO): calculated from the known data 90 km2, maximal estimation ca. 780 km2 (if all the hilly habitats in Hvar Is. and Vis Is. are included).
Newly proposed status. The species is reassessed here as Endangered. Up to now, the species has been known from only two Adriatic islands (Hvar and Vis). Inhabiting a restricted number of sites, it has an AOO of 12 km2 to maximally 80 km2, and a known EOO of 90 km2 (maximally estimated less than 800 km2). This makes it qualify for EN, following the criteria B1ab(iii)+B2ab(iii). Since there are only three sites at which this species occurs with certainty, only a few threat events may be enough to wipe out or threaten proportional parts of the population. Forest fires, for example, occur quite often on the Adriatic islands and can damage important parts of the species’ habitat, as can touristic and recreational developments and clear cutting of maquis and scrubland.
Tribe Platycleidini Brunner von Wattenwyl, 1893
Rhacocleis Buchichii
Br.:
Rhacocleis
Bucchichii (O. Herman):
Rhacocleis Bucchici
Br.:
Anterastes
Bucchichi:
Rhacocleis Bucchici
Br. 1874:
Rhacocleis bucchici
Rhacocleis bucchici
Herm.:
Rhacocleis Buchichii, Herm.:
Rhacocleis
Buchicii Br. 1874:
Rhacocleis Bucchici:
Rhacocleis buchichii
Herman:
Rhacocleis bucchici
Herm.:
Rhacocleis buchichii
Herm.:
Rhacocleis bucchichi
Br.:
Rhacocleis bucchichi
Br.:
Rhacocleis bucchichi
Hermann, 1874:
Rhacocleis bucchici
Herm. 1874:
Rhacocleis buchichi
Herm.:
Rhacocleis bucchicii
Hermann, 1874:
Pterolepis bucchicii
(Herman, 1874):
Rhacocleis bucchichi
Herman, 1874:
Rhacocleis buchichii:
Rhacocleis buchichii
Rhacocleis buchichii:
Rhacocleis buchichii:
Rhacocleis buchichii
Brunner von Wattenwyl in Herman, 1874:
Historically, the species name of Rhacocleis buchichi was misspelled a lot, for obvious reasons. It was even misspelled more often than cited correctly (see above). One specific misspelling, bucchichi, can be explained by the fact that the person after whom the species was named is Grgur/Gregorio Bučić/Bucchich (1829–1911), a Croatian naturalist with a surname that contains two consonants (voiceless postalveolar affricate consonant č, pronounced /tʂ/; and voiceless alveolo-palatal affricate ć, pronounced /tɕ/). These consonants were written in Croatian language in many different ways (ch, cch, ci, cci, chi) in the past, which has probably caused the confusion.
The first published spelling and the oldest drawings of Rhacocleis buchichii after
Syntypes of Rhacocleis buchichii, one male and one female, are deposited in
Photos of syntype male and female of Rhacocleis buchichii by Naskrecki, taken from OSF (
Croatia • 1♂; Vis Is., Mount Hum; 43°02.13'N, 16°06.92'E; alt. 545 m a.s.l.; 21 Jul. 2011; R. Felix leg.; RFPC • 2♂; Hvar Is., between Jelsa and Gdinj; 25 Jul. 1982; K.-G. Heller leg.; KGHC CH0531 and CH2167 • 1♀; Biokovo Mt., above Tučepi; alt. 500 m a.s.l.; 43°16'N, 17°05'E 28 May 2006; M. & K.-G. Heller leg.; KGHC CH6779 • 1♂, nymph; Brač Is., near Pučišća; 31 May 2006, M. & K.-G. Heller leg.; KGHC CH6783 • 1♀; Troglav Mt., southern slope; alt. 850 m a.s.l.; 29 Aug. 2014; J. Skejo leg.; ZSZJS • 2♀; Hvar Is., 500 m south of Pitve; alt. 300 m a.s.l.; 13 Aug. 1996; R. Kleukers leg.; NBC RMNH.INS.960939 and RMNH.INS.1259083 • 1♂; Hvar Is., 500 m east of Vrisnik; alt. 150 m a.s.l.; 13 Aug. 1996; R. Kleukers leg.; NBC RMNH.INS.1259084; sound recorded • 1♂; Hvar Is., 500 m south of Pitve; alt. 300 m a.s.l.; 13 Aug. 1996; R. Kleukers leg.; sound recorded; specimen lost.
A single male individual of Rhacocleis buchichii was found under a Juniperus bush near the Chapel of St. Spirit (Crikvica Sv. Duha) at Mount Hum, in the southwestern corner of Vis Is. (43.036N, 16.116E, 545 m a.s.l.) (Figs
All known records of R. buchichii are depicted on the map in Fig.
Known records of Rhacocleis buchichii, with data on the sites and collection events. Type specimens collected on ‘Lesina’ (Hvar Is.) and labelled as such are not included in the table, nor are depicted on the map in Fig.
Date of collection | map | Specimens | Location | Coll. | Reference |
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25 Oct. 1875 | 8 | n/c? | Hvar Is., Brusje |
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25 Oct. 1875 | 10 | n/c? | Hvar Is., Mt. Humac |
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20 Jul. 1912 | 5 | n/c? | Brač Is., south of Nerežišća |
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18 – 25 Aug. 1939 | 8 | 7 | Hvar Is., Brusje, below 500 m. a.s.l. |
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Aug. 1964–1966 | 14 | 1 | Zaostrog |
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25 Jul. 1982 | 11 | 2♂ | Hvar Is., between Jelsa and Gdinj | KGHC | |
13 Aug. 1996 | 9 | 1♂ 2♀ | Hvar Is., Pitve, 300 m a.s.l. | NBC | |
13 Aug. 1996 | 9 | 1♂ | Hvar Is., Vrisnik, 150 m a.s.l. | NBC | |
18 Aug. 2002 | 6 | 1♂ | Brač Is., Bol, Mt. Vidova Gora, 43°16.77'N, 16°37.14'E, 770 m a.s.l. |
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28 May 2006 | 12 | 1♀ | Biokovo Mt., above Tučepi, 43°16'N, 17°5'E, 500 m a.s.l. | KGHC | |
31 May 2006 | 7 | 1♂ juv | Brač Is., near Pučišća | KGHC | |
21 Jul. 2011 | 1 | 1♂ | Vis Is., Mt. Hum, Crikvica Sv. Duha, 43°02.13'N, 16°06.92'E, 545 m a.s.l. | RFPC | |
29 Aug. 2014 | 4 | 1♀ | Southern slope of Mt. Troglav, Greda, 43°49.33'N, 16°38.48'E, 850 m a.s.l. | ZSZJS |
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13 Oct. 2015 | 13 | 10♂♀ | Biokovo Mt., 43°15.59'N, 17°05.57'E, 650 m a.s.l. |
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16 Oct. 2015 | 13 | 5♂♀ | Biokovo Mt., 43°15.32'N, 17°06.02'E, 650 m a.s.l. |
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The first information on the habitat of R. buchichii was given by the name bearer himself;
We regard this song description as preliminary, as we were able to analyse the sound recordings of only two males. The calling song of R. buchichii consists of echemes that are repeated in a series of 4–13. However, in one of the recordings only the series of 2–5 occur. Echemes are repeated at a rate of ca. one or two echemes/s. In the available recordings, no continuous repetition of echemes is found. Echemes seem to have a more or less fixed structure, last ca. 160–220 ms and contain 7–9 syllables. Syllables are repeated at a rate of 40–50/s (26–27 °C).
Within Tettigoniidae, the members of the Platycleidini tribe have either an unarmed prosternum or the prosternum bears two spines (
Based on the shape of the cerci of the male and the subgenital plate of the female,
Rhacocleis buchichii is easily distinguished from its only congener in Croatia, R. germanica (Herrich-Schäffer, 1840). The cerci of R. buchichii males are very slender, while the males of R. germanica have more robust cerci, with a less elongated distal part. Each cercus of male R. germanica has a long and straight inner tooth. Females of R. buchichii have a rectangular subgenital plate with a median keel, which is armed at the tip (Fig.
The song (Table
Echeme repetition rate and the number of syllables per echeme are considered to be the main distinguishing features of different species.
Bioacoustic data of R. buchichii, R. germanica, R. japygia, and R. neglecta. Presented are echeme repetition rates per second, number of syllables per echeme, and syllable repetition rate per second. Data of R. germanica and R. neglecta obtained from
Species | Echeme repetition rate (/s) | Syllables per echeme | Syllable repetition rate (/s) |
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R. buchichii | 1–2 | 7–9 | 40–50 |
R. germanica | 0,3–1 | 10 | 40 |
R. japygia | 1–2,5 | 5–7 | 30 |
R. neglecta | 1–3 | 3–5 | 25–40 |
1 | Male cerci long and slender, inner tooth positioned at the basal fifth of the cercus, the apex of the tooth curved inward. Female subgenital plate rectangular, with a median keel thickened towards the apex. [currently known only from Brač Is., Hvar Is., Vis Is., and some inland and coastal mountains] | Rhacocleis buchichii Brunner von Wattenwyl in Herman, 1874 |
– | Male cerci robust, inner tooth positioned just at the basis of the cercus, long and straight, in a right angle with the cercus. Female subgenital plate elongated, without a median keel and with an apical incision. [Common in the whole Mediterranean part of Croatia, including islands, and mountains; less common in Panno-nian region] | Rhacocleis germanica (Herrich-Schäffer, 1840) |
Current status. Endangered (EN) in Europe and EU28 (
Area of occupancy (AOO): calculated from the known data (ca. 10 sites) 60 km2, maximal estimation 400 km2.
Extent of occurrence (EOO): calculated from the known data 3700 km2, maximal estimation ca. 7400 km2.
Newly proposed status. Lesina Bush-cricket inhabits the Adriatic islands of Hvar, Brač and Vis, as well as certain mountains in mainland Dalmatia. Since the species has recently been found on Vis Is. and its presence on Troglav Mt. has now been confirmed, its known range has extended significantly compared to the previous assessment. Based on the above calculations, we propose the species to be downgraded to a less threatened category.
The species occurs in Natura 2000 protected areas (Vis Is., Hvar Is., Brač Is.) and in a protected natural park (Biokovo Natural Park), but it is expected to occur outside the protected areas as well, where the main threats to the species’ survival persist. Based on numerous references, the habitat type of the species, to be considered in a future reassessment, has to be extended with scrubland (see above, under Habitat).
The Adriatic islands are of a rather young evolutionary age (
Nevertheless, a few endemics known from the central Dalmatian islands, mainly documented in plants (
The terrestrial fauna of most Croatian islands still remains profoundly understudied and the Orthoptera of the Central Dalmatian islands, in particular, have never been studied systematically (
To start with the less complex case, the Lesina Bush-cricket Rhacocleis buchichii is endemic to Dalmatian islands (Brač, Hvar, Vis) and mountains (e.g., Troglav and Biokovo), and occurs sympatrically with R. germanica, the latter being very common in the Mediterranean region of Croatia. The two species show clear morphological differences and do not seem to be closely related. On the other side of the Adriatic Sea, in Italy, two species presumably closely related to R. buchichii and each other occur, namely R. neglecta and R. japygia (
Despite the fact that the similarity between the three species was mentioned as early as 60 years ago (
The situation with Hvar Saw Bush-cricket Barbitistes kaltenbachi is quite different and much more complex. This flightless bush-cricket is endemic to two Dalmatian islands (Hvar Is. and Vis Is.). The song of B. kaltenbachi is unique within the genus and does not resemble that of any other known species (Figs
According to the cercal morphology, B. kaltenbachi could be closely related to B. constrictus, their cerci being nearly identical (Fig.
Looking at the distribution ranges of other Barbitistes species, one can recognise an intriguing gap between the northern and southern distributional areas of B. ocskayi (see
Based on the shape of the subgenital plate, B. kaltenbachi is similar to ocskayi. Based on cercal morphology, however, B. ocskayi and B. yersini seem to resemble each other more. Barbitistes vicetinus is a species restricted to Northern Italy, which exhibits an isolated occurrence comparable to that of B. kaltenbachi. Despite a superficial resemblance of the male cerci of B. kaltenbachi and B. vicetinus (the latter also has a somewhat thickened mid-part; Fig.
Barbitistes kaltenbachi belongs to Phaneropterinae, a bush-cricket subfamily in which females of most species do not respond to male songs only by phonotactic approach, but also react with their own acoustic signals. These sounds are used by males for locating females (see
Male calling songs of all species belonging to Barbitistini sensu stricto (genera Barbitistes, Metaplastes, and Ancistrura) are characterised by short, isolated syllables showing a species-specific pattern (
During the duets of B. kaltenbachi, trigger syllables/verses of both males started within only 20 ms (Fig.
Unfortunately, as nothing is known about female acoustic behaviour or the potential male reaction, the hypotheses regarding B. kaltenbachi acoustic behaviour can only be based on what is known of other species. Barbitistes females respond to the trigger syllable after a delay of ca. 40 ms (
With this paper, we attempted to enhance the information on the distribution of two Croatian endemic bush-crickets, as well as the knowledge of their morphology and bioacoustics. The songs of Barbitistes kaltenbachi and Rhacocleis buchichii are described here for the first time. The IUCN Red List status has been reassessed here for both species; we suggest R. buchichii to be downgraded to a less threatened category, while B. kaltenbachi should be upgraded to ‘Endangered’.
The knowledge of the biology of both species is still scarce. Barbitistes kaltenbachi is suspected to be active early in the season, while R. buchichii is probably active late in the season, based on many records of this species from October (see Tables
The fact that the type series of B. kaltenbachi consists of a fairly large number of specimens (22) from the same locality (
To enrich the knowledge of the Orthoptera fauna of Vis Is. and other Adriatic islands, the authors would like to suggest visiting entomologists to pay attention to these and other species, and enter their sightings, accompanied by photos, on websites such as Observation (www.observation.org) or iNaturalist (www.iNaturalist.org).
The authors wish to thank Harald Bruckner and Susanne Randolf of the Museum of Natural History in Vienna for providing photographs of male and female syntypes of B. kaltenbachi at the time when no digitised photos existed in OSF. Roy Kleukers is thanked for proving us with information about his records of R. buchichii on Hvar in 1996. Luc Willemse (NBC) provided some excellent photos of Roy’s material deposited in NBC. Joris Verhees kindly agreed to the first author’s request to gather additional data on B. kaltenbachi on Vis in 2018, but unfortunately without finding the species – we thank Joris for his efforts. Thanks to Nikola Tvrtković, Marianne Volleth, Martina Heller and Martijn Bunskoek for their help with fieldwork. Thanks to Andreas Stumpner for providing Barbitistes sound recordings from Slovenia. Bruno Massa is thanked for providing help in deciphering some technical Italian species descriptions. Finally, we would like to thank our reviewers Judith Marshall, Bruno Massa, and Slobodan Ivković for their suggestions and comments. The Funding for Open Access Publishing service of the Heinrich Heine University, Düsseldorf, covered the expenses of the publication of this paper.
The general idea for the study was initialised by JS and RF. JS, RF, and KGH conducted field research on the two endemic species on Hvar Is. (KGH with success, JS without success), Brač Is. (KGH with success, JS without success), Vis Is. (RF), Biokovo Mt. (KGH with success, JS without success), and Troglav Mt. (JS). KGH, FR, and JS conducted research on other Barbitistes and Rhacocleis species in Croatia. All the authors compiled literature data, discussed the data, and photographed material. KGH conducted bioacoustics analysis of B. kaltenbachi and wrote that part of the study. BO did the same for R. buchichii. The rest of the study was written mainly by RF, JS, and KGH, with the help of FR.
Barbitistes kaltenbachi morphometrics
Data type: Microsoft Word Document (.docx)
Explanation note: Table S1. Morphometrics of Hvar Saw Bush-cricket. Published measurements (
Rhacocleis buchichii morphometrics
Data type: Microsoft Word Document (.docx)
Explanation note: Table S2. Morphometrics of Lesina Bush-cricket. Published measurements (
Barbitistes kaltenbachi bioacoustics and comparative morphology
Data type: Microsoft Word Document (.docx)
Explanation note: Table S3.1. Measurements of the amplitudes in the song of Barbitistes kaltenbachi; Table S3.2 Measurements of the species-specific time pattern in the song of Barbitistes kaltenbachi; Table S3.3 Measurements of the parameters of calling activity of Barbitistes kaltenbachi; Table S3.4 Sampling locality data for the specimens used in Fig.