Island mysteries in the spotlight: Barbitistes kaltenbachi and Rhacocleis buchichii, the only bush-cricket species endemic to Croatia (Orthoptera, Tettigoniidae) Author Felix, Rob IUCN / SSC Grasshopper Specialist Group, Gland, Switzerland & Nijmegen, the Netherlands https://orcid.org/0000-0003-1564-3781 robfelix1@gmail.com Author Heller, Klaus-Gerhard IUCN / SSC Grasshopper Specialist Group, Gland, Switzerland & Grillenstieg 18, D- 39120 Magdeburg, Germany https://orcid.org/0000-0002-3331-3228 Author Ode, Baudewijn IUCN / SSC Grasshopper Specialist Group, Gland, Switzerland & De Bongerd 29, 6584 DG Molenhoek, the Netherlands Author Rebrina, Fran IUCN / SSC Grasshopper Specialist Group, Gland, Switzerland & University of Zagreb, Faculty of Science, Department of Biology, Division of Zoology, Animal Ecology and Zoogeography Lab, Rooseveltov trg 6, HR- 10000 Zagreb, Croatia Author Josip Skejo, IUCN / SSC Grasshopper Specialist Group, Gland, Switzerland & University of Zagreb, Faculty of Science, Department of Biology, Division of Zoology, Evolution Lab, Rooseveltov trg 6, HR- 10000 Zagreb, Croatia & Heinrich-Heine-Universitaet Duesseldorf, Institute of Molecular Evolution, D- 40225, Duesseldorf, Germany https://orcid.org/0000-0002-2554-4499 skejo.josip@gmail.com text ZooKeys 2020 936 25 60 http://dx.doi.org/10.3897/zookeys.936.51599 journal article http://dx.doi.org/10.3897/zookeys.936.51599 1313-2970-936-25 668E08BD6383403FB29CF47CA7C50E80 CEE94A684E455876A785F3C060AE77F0 Rhacocleis buchichii Brunner von Wattenwyl in Herman 1874 Figures 1 , 9 , 10 , 11 , 12 Rhacocleis Buchichii Br.: Herman (1874) : 201-202, plate III, figs 8-12 (original Brunner von Wattenwyl's description accompanied with figures; erroneously calls buchichii type species of the genus) (see Figs 9 , 10 in this paper); Rhacocleis Bucchichii (O. Herman): Dubrony (1878) : 21 (misspelled; reported the species from Liguria, based on misidentification of another Rhacocleis sp.); Rhacocleis Bucchici Br.: Brunner von Wattenwyl (1882) : 321 (misspelled; included in key), 322 (description, measurements, and Hvar, Lesina, designated as distribution); Anterastes Bucchichi: Bucchich (1886) : 382 (misspelled; Bucchich wrote a remark "In Luglio nei cespugli specialmente di erica; nei campi non si vede", "In July found in bushes, especially of Erica ; but not observed in fields" [= karst poljes]); Rhacocleis Bucchici Br. 1874: Novak (1888) : 129 (misspelled; provides first exact localities, Brusje and Humac on Hvar Is., and added data on Bucchic's comments on species' habitat: "Io ne ho trovato nel bosco ordinariamente fra il Cystus monspeliensis dal mese di giugno all' ottobre, in agosto in casa introdotto forse colla frasca, negli orti fra i rosai, a Brusje e monte Humac in ottobre (25) sul Quercus ", "Usually I found them in bushes [or forest], under Cystus monspeliensis from June to October. In August in houses, probably with branches. Found in gardens under roses. In Brusje and Humac found on Quercus on October 25th"); Rhacocleis bucchici Herman 1874 : Redtenbacher (1900) : 107 (misspelled; gives a short morphological description of the species with measurements and mentions the species to occur on the island of Lesina); Rhacocleis bucchici Herm.: Jacobson and Bianki (1905) : 400 (misspelled; colouration and morphology described in Russian, measurements provided, distribution cited 'Dalmatia' ); Rhacocleis Buchichii , Herm.: Kirby (1906) : 187 (listed in catalogue); Rhacocleis Buchicii Br. 1874: Karny (1907a) : 26 (misspelled; lists sp. in catalogue, citing Brunner von Wattenwyl, Novak and Redtenbacher); Rhacocleis Bucchici : Karny (1907b) : 131 (misspelled; mentions that the species has been known only from Hvar Is.); Rhacocleis buchichii Herman: Caudell (1908) : 5 (listed in the catalogue of Decticinae species, mentioned as endemic to Hvar Is.); Rhacocleis bucchici Herm.: Werner (1919) : 217 (misspelled; mentions species to occur on Brac Is., "south of Neresi, near the water tanks in the bushes, not common". Also mentions "species until then only known from Lesina"); Rhacocleis buchichii Herm.: Salfi (1924) : 43, 45 (key to species); Rhacocleis bucchichi Br.: Ramme (1951) : 118 (reported to have found the species in hilly terrain under Pistacia terebinthus L. and noted that the species was timorous and difficult to catch); Rhacocleis bucchichi Br.: La Greca (1959) : 43, 148, fig. 115 (148) (misspelled; treats all the species of the genus and mentions buchichii to be present on Lesina Is., also shown on a distribution map of Italian species); Rhacocleis bucchichi Hermann, 1874: Us (1967) : 23 (misspelled; checklist of Yugoslavian Orthoptera , cited from Hvar, Brac and Korcula); Rhacocleis bucchici Herm. 1874: Harz (1969) : 429-441 (misspelled; included in key to European species, depicted in detail, figs 1343, 1361, 1396-1400, described and measured, distribution Hvar, Brac and probably also Korcula ); Rhacocleis buchichi Herm.: Gausz (1970) : 131 (misspelled; first mainland record at Zaostrog along the Dalmatian coast); Rhacocleis bucchicii Hermann, 1874: Heller (1988) : 147, Abb. 146 F, I (F) (misspelled; mentions the species to occur on Hvar Is., lists a collecting event on 25 July 1982 and depicts the stridulatory file) Pterolepis bucchicii (Herman, 1874): Heller et al. (1998) : 37 (misspelled; species listed in checklist of European Orthoptera ); Rhacocleis bucchichi Herman, 1874: Willemse and Willemse (2005) : 269 (misspelled; listed in checklist of Rhacocleis and Pterolepis species, 6 specimens from Dalmatia examined, in R. Kleukers and K.-G. Heller's collections); Rhacocleis buchichii : Skejo (2014) (assessed as Endangered species in IUCN Red list); Rhacocleis buchichii Herman 1874 : Wagner (2015) : 37-41 (new record from Biokovo Mt., photographs provided); Rhacocleis buchichii : Hochkirch et al. (2016a) (assessed as Endangered species in IUCN Red list, distribution Hvar, Brac and probably Korcula ); Rhacocleis buchichii : Hochkirch et al. (2016b) : 20, 76 (listed among Endangered species in European Orthoptera fauna); Rhacocleis buchichii Brunner von Wattenwyl in Herman, 1874: Skejo et al. (2018) : 33 (author corrected to Brunner von Wattenwyl, species distribution in Croatia and Europe presented). Historical misspellings. 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 Bucic /Bucchich (1829-1911), a Croatian naturalist with a surname that contains two consonants (voiceless postalveolar affricate consonant c , pronounced /tʂ/; and voiceless alveolo-palatal affricate c , 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. Figure 9. The first published spelling and the oldest drawings of Rhacocleis buchichii after Herman (1874) ( A-E ) and Brunner von Wattenwyl (1882) ( F-H ) A head and pronotum in lateral view B head and pronotum in dorsal view C cerci of a male D subgenital plate of a female E ovipositor F habitus of a female in lateral view G cerci of a male H hind leg details, apex of tibia and tarsus. Drawings not to scale. Type material. Syntypes of Rhacocleis buchichii , one male and one female, are deposited in MfN, Berlin (Fig. 10 ). In the collection of NMW, Vienna, there are three specimens from the collection of Brunner von Wattenwyl (pers. comm. S Randolf). These three specimens are not labelled as types, but since they are part of the type-collection, they should be considered syntypes too. Figure 10. Photos of syntype male and female of Rhacocleis buchichii by Naskrecki, taken from OSF ( Cigliano et al. 2019 ) ( A-D ) drawings from Harz (1969) ( E-I ) and details of specimens from Croatia, Hvar Is., near Pitve and Vrisnik, 13 Aug. 1996 (collection NBC) ( J-L ) (photos Luc Willemse, NBC) A male syntype and its label B pronotum and tegmina of the male in dorsal view C female syntype and its label D cerci and 10th tergite of the male E subgenital plate of a female F titillators G 10th tergite of a male H ovipositor I right cercus of a male J titillators lateral view K titillators caudal/posterior view L subgenital plate of a female. Scale bars: 5 mm ( A-D, L ); 1 mm ( J, K ). Drawings not to scale. Material examined. 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 Tucepi ; alt. 500 m a.s.l.; 43°16'N , 17°05'E 28 May 2006; M. & K.-G. Heller leg.; KGHC CH6779 • 1♂, nymph; Brac Is., near Pucisca ; 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. New record from Vis Island. 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 1 , 2A , 11 ). Several photographs of the specimen were taken in its natural habitat (Fig. 11C ), and it was subsequently collected (Fig. 11 ). As in the case of Hvar Saw Bush-cricket, this is the very first record of Lesina Bush-cricket for the island of Vis. It was recorded in the direct vicinity of the collecting site of Barbitistes kaltenbachi . Figure 11. Habitus of Rhacocleis buchichii , Croatia, Vis Is., Mount Hum A male B cerci of the male C the same specimen in situ. Scale bars: 5 mm. Distribution. All known records of R. buchichii are depicted on the map in Fig. 1 and presented in Table 2 . After its description from Hvar Is., the species has been found at scattered localities on the island and in a wide area outside the island: Zaostrog ( Gausz 1970 ), Biokovo Mt. (present paper; Wagner 2015 ), Brac Is. (present paper; Puskas et al. 2018 ) and Troglav Mt. within the Dinara Massif ( Skejo et al. 2018 ). Harz (1969) mentions the species' occurrence on Korcula Is., but its presence on the island has never been confirmed. Table 2. 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. 1 . Key: n/c, not collected.

Date of collection	map	Specimens	Location	Coll.	Reference
25 Oct. 1875	8	n/c?	Hvar Is., Brusje	-	Novak (1888)
25 Oct. 1875	10	n/c?	Hvar Is., Mt. Humac	-	Novak (1888)
20 Jul. 1912	5	n/c?	Brac Is., south of Nerezisca	-	Werner (1919)
18 - 25 Aug. 1939	8	7	Hvar Is., Brusje, below 500 m. a.s.l.	-	Ramme (1951)
Aug. 1964-1966	14	1	Zaostrog	-	Gausz (1970)
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♂	Brac Is., Bol, Mt. Vidova Gora, 43°16.77'N , 16°37.14'E , 770 m a.s.l.	-	Puskas et al. (2018)
28 May 2006	12	1♀	Biokovo Mt., above Tucepi , 43°16'N , 17°5'E , 500 m a.s.l.	KGHC	-
31 May 2006	7	1♂ juv	Brac Is., near Pucisca	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	Skejo et al. (2018)
13 Oct. 2015	13	10♂♀	Biokovo Mt., 43°15.59'N , 17°05.57'E , 650 m a.s.l.	-	Wagner (2015)
16 Oct. 2015	13	5♂♀	Biokovo Mt., 43°15.32'N , 17°06.02'E , 650 m a.s.l.	-	Wagner (2015)

Habitat. The first information on the habitat of R. buchichii was given by the name bearer himself; Bucchich (1886) found the species in July in a hilly terrain in bushes, especially Erica . He mentions that the species does not occur in fields (see Bibliography). Novak (1888) also mentions hilly areas as the prime habitat, adding that the species can be found from June to October under Cistus monspeliensis . Some individuals entered the house, probably as stowaways in collected firewood. In gardens, it was found under roses. Ramme (1951) reported the species to live under Pistacia terebinthus and noted that it was timorous and difficult to catch. Gausz (1970) found a specimen in the littoral zone near Zaostrog, in the undergrowth (karst-steppe vegetation of 3-10 cm high) in a stand of Ficus carica and Olea europaea . Kleukers (pers. comm.) found R. buchichii in 1996 on a rocky slope with low bushes around the villages of Pitve and Vrisnik, Hvar Is. Wagner (2015) found R. buchichii on Biokovo Mt., under Black Pine, Pinus nigra , while JS found it on Troglav Mt. under Pistacia sp. On 25 Jul. 1982, KGH found many specimens at night, walking and jumping on the road between Jelsa and Gdinj. Song description. 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). Species diagnosis. Within Tettigoniidae , the members of the Platycleidini tribe have either an unarmed prosternum or the prosternum bears two spines ( Massa et al. 2012 ). The Rhacocleis genus belongs to the latter group, together with Pterolepis Rambur, 1838, Antaxius Brunner von Wattenwyl, 1882, Anterastes Brunner von Wattenwyl and Yersinella Ramme, 1933, among others. Based on the shape of the cerci of the male and the subgenital plate of the female, La Greca (1959) placed R. buchichii into the Rhacocleis neglecta -species group ( La Greca 1959 ), composed of R. neglecta (Costa, 1863), R. japygia La Greca, 1959 (both from central and southern Italy) and R. buchichii (Croatia). These species are characterised by 1) slender cerci with a decurved inner tooth close to the base (♂♂) and 2) a quadrate subgenital plate with a central keel and lateral depressions (♀♀). Rhacocleis buchichii is characterised by very small, neglecta -type titillators (Fig. 10J, K ), but with a blunt and rounded apex ( La Greca 1959 ). Cerci of the male are conical, delicate, very long and have a medial tooth protruding ca. 1/5 from their base (Figs 10 , 11 ). La Greca (1959) provides a detailed description of the subgenital plate of the female: it presents a median carina and two lateral carinulas arranged obliquely and converging to the centre, towards the apex of the median carina. Transversal grooves on both sides of the median carina are situated more towards the apex of the subgenital plate than towards its base, and are limited posteriorly by the two lateral carinulas (Fig. 10L ). Rhacocleis buchichii is easily distinguished from its only congener in Croatia, R. germanica ( Herrich-Schaeffer , 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. 10L ), while R. germanica females have a prolonged, oval subgenital plate with an apical incision. The two Croatian species also differ in colouration. Rhacocleis germanica is more reddish and brownish tinted, without a white band on the paranota of the pronotum. Rhacocleis buchichii has darker and greyer tints and has a clear pale paranotal band (Figs 10 , 11 ). See Suppl. material 2: Table S2 for the measurements of specimens in collections and literature data. The song (Table 3 ) is different from the song of R. germanica in the number of syllables per echeme, being ca. ten in R. germanica , and 7-9 in R. buchichii . In R. japygia echemes are repeated in short series (2-8 echemes) or more or less continuously, with a repetition rate of ca. 1-2.5 echemes/s. Echemes consist of 5-7 syllables which are repeated at a rate of ca. 30/s. In R. neglecta , echemes are produced in long series or continuously, at a rate of 1-3 echemes/s. Echemes consist of 3-5 syllables. Syllables are repeated at a rate of ca. 25-40/s. Echeme repetition rate and the number of syllables per echeme are considered to be the main distinguishing features of different species. Table 3. 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 Ragge and Reynolds (1998) and Heller (1988) , data of R. japygia obtained from Massa et al. (2012) .

Species	Echeme repetition rate (/s)	Syllables per echeme	Syllable repetition rate (/s)
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