Searching for exuviae of endemic Odonata species in

Transcription

1 Searching for exuviae endemic Odonata species in Greece C. Brochard & E. van der Ploeg Introduction rva and exuvia Coenagrion intermedium Only a few major papers have been published were described by Battin (1991), one year on the Odonata fauna Corfu (Sutton, 2009) ter than the adults (Lohmann,1990). Jodicke and Crete (Battin, 1989). In 2010, an ats the Odonata Greece published by Lopau (2005) conducted a study on the distribution Coenagrion intermedium on Crete. He also (2010) which comprises almost all avaible provided information on the coloration, niche records. Most papers only deal with the endemic specificity and reproduction behaviour that or the Critically Endangered species these species. isnds. Kalkman & Lopau (2006) describe the morphological differences between Pyrrhosoma nymphu and P. elisabethae for both male and female adults and present an overview the distribution P. elisabethae. Although the In 2010, we started a project to create a photographic guide for exuviae European dragonflies, in which we hope to provide identification keys for the exuviae all European imagines Boyeria cretensis were described Odonata species. One the major difficulties two decades ago (Peters, 1991), the description such a project is to collect or locate exuviae the rva this species published only all these species. These are required not very recently by MOller et al. (2012). It is remarkable that a study on the behaviour the imagines undertaken (Schneider & only for taking photographs also for taking the necessary differentiate between closely for the book, but measurements to reted species. Muller, 2006) before the rva known. The In such cases many individuals are needed for statistical validation identification criteria. To add to the project s difficulties, the knowledge exuviae dragonflies in south eastern Europe is poor, as illustrated by e.g. P. elisabethae, which the rva and exuvium have only recently been discovered (Brochard & Van der Ploeg, 2012). For the endemic species, insufficient material avaible. We therefore decided to go on a field trip to some the Greek isnds in order to collect rvae and exuviae these rare and threatened dragonflies. In May 2012, we surveyed the Greek isnd Corfu (or Kerkira) with the intention to find P. elisabethae, a species endemic to Greece and Albania. In June 2012 we visited the isnd Crete, with the aim collecting exuviae the endemic species C. intermedium and Boyeria cretensis. In this article we present the results these two trips. Figure 1. Locations visited on the Greek isnd Corfu. Brachytron 15(2): ,

2 Figure 2. Locations visited on the Greek isnd Crete. Material & Methods in order to make sure that no insects or spiders could damage them. The rvae were caught by Collecting exuviae The search for exuviae, especially rare use a scoop net and were kept in a cool box during fieldwork. An aquarium and photographic species, can be difficult. This is not only because exuviae may be difficult to find in the field, but also because information on precise locations equipment were sent to both isnds in order to take photographs living rvae. We did not sex the specimens in the field (adults, exuviae where the species occur is either not there or or rvae) because we wanted to spend most not clearly given in publications. Fortunately, our time searching for exuviae. Sexing rvae such information is at least partly avaible for is not always as easy as for most species the C. intermedium (Jodicke, 2005), P. elisabethae family Libellulidae (Brochard et al, 2012). A (Kalkman (MOller & Lopau, 2006) and for B. cretensis et al., 2012). We also made use the GPS used to locate the sites we would like to visit, and to georeferate the newly investigated publication Lopau (2010). locations. One the most difficultaspects searching for Localities exuviae is to be in the right pce at the right The selection the sites we wanted to visit time the year. If you arrive too early in the based on the known or suspected occurrence season, only rvae are present and if you are too te, rvae have emerged and exuviae may have disappeared. Weather conditions make the P. elisabethae on Corfu and on the known or suspected occurrence C. intermedium and Boyeria cretensis on Crete. This information search for exuviae even more difficult as wind partly found in Lopau (2010) and Muller et al. and rain can affect emergence and will have (2012), or kindly provided to us by Vincent effects on the preservation the exuviae in the Kalkman, Jean-Pierre Boudot and Fons Peels. following days. A touch luck is vital for the Additional locations were selected by analysing search to be successful. topographical maps and satellite images for the Most imagines could be identified visually or presence suitable biotopes for these species, or for other species which we had only few with the help binocurs. If necessary, an exuviae in our collection, such as Trithemis insect net used to catch individuals for annuta and Selysiothemis nigra. identificationin the hand. Exuviae were found by looking for suitable pces for emergence. The This resulted in 12 investigated locations on collected exuviae were stored in small pstic the isnd Corfu (Figure 1) and 18 on the boxes and put in a freezer for at least 12 hours isnd Crete (Figure 2). They are numbered 84

3 Locations onthe isnd Corfu Log. 1: Dune ponds, 2 km northwest Pithos, 300 m from the coast, Corfu; N39 48,711' E ; 12 May Loc. 7: Small brook, 650 m north-northeast Drosato, Corfu; N E '; 10 May In the most northerly dunes Corfu, some dune Near Drosato, a small stream comes out a densely ponds can be found about 300 meters south wooded area and flows alongside an allotment. the shoreline. The ponds are very shallow and as a result, the temperature the water high. At these ponds, reeds, and grasses sedges emerged from the water in high density (Figure 3). These ponds were rich in very nutrients, due to intensive grazing by cattle. Over a length about 30 m, the stream is fully exposed to the sun, and only about 0.3 m wide, with a depth approximately 5 cm, (Figure 5), Upstream from this shallow stretch, the stream is wider (2 m) and deeper (over 1 m) and completely shaded. Downstream, the water flows through two concrete culverts beneath an unpaved road and continues as Loc. 2: Dune ponds, 1.5 km northwest Vasilika and 800 m from the coast, Corfu; N a two metre wide, shallow river, which is overgrown with grasses and herbs and surrounded by trees E ; 13 May 2012, and shrubs. Loc. 3: Melissoudi River, 1 km south-southeast Loc. 8; River, 450 m southwest Kipriandes, Corfu; Sidari, Corfu; N ' E19M3.040; 6 May 2012, N39M4.240' E ; 12 May May 2012 and 12 May The Melissoudi River flows in a northerly direction Loc. 9: Small kes, 1 km northwest Roudes, to the sea and has a sandy substrate. This river Corfu, N E , 7 May is bordered by a line trees and bushes (Figure These natural kes (Figure 6) in the hills near 4), with an abundant undergrowth brambles Roudes have a well-developed aquatic vegetation and nettles. Locally, reeds are present along the and are surrounded by fields and forests. banks. As a consequence, the river is at least partly overshadowed for most the day. In May 2012 the river flowing slowly, with some small and shallow rapids. The slow-flowing parts were deeper, Loc. 10: Small river, 1.9 km east-northeast Giannades, Corfu; N E '; 7 May 2012, with some stretches deeperthan 1.5 m. In wintertime the depth the river sometimes exceeds 10 metres, Loc. 11: River, 1.3 km west Episkopiana, Corfu; causing the water to be channelled through the valley at high speed. N E ; 11 May Loc. 12: Water reservoir, 1.3 km southwest Kavos, Loc. 4: Garden, 1.7 km west-southwest Karousades, Corfu; N ' E ; 7 May 2012, Corfu; N E20 06,357 ; 9 May This man-made reservoir is situated in the far southeast the isnd and is characterised by the presence many boulders on the shore (Figure Loc. 5: River, 900 m east Kopsochides, Corfu; N E19M3.811 ; 10 May ). Riparian vegetation is only marginally present. The edges the reservoir are quite steep and it is thoughtto be several metres deep in the middle. The Loc. 6: Water reserve, 370 m east-northeast Petalia on mount Pantokrator, Corfu; N surrounding ndscape holds a mix grassnds, forest and bramble bushes. E ; 13 May 2012, from north to south for Corfu and from west to Results and annotations on some species east for Crete. For each these 30 sites, the name the nearest vilge is given. Whenever Altogether 37 species Odonatawere observed on Corfu and Crete. On Corfu, more than 1,700 Possible the name the river, pond or ke is exuviae 24 species were collected. Six more added. This is followed by the GPS coordinates species were observed only as imagines (Table (Latitude, Longitude using WGS 84 projection) 1). On Crete, 23 species were noted and more and the date observation. For both isnds we describe the most interesting locations. than 5,800 exuviae 19 species (Table 2). were collected Brachytron 15(2): ,

4 Locations on the isnd Crete Loc. 13: Lake Kourna, west Kavallos, Crete; is probably several metres deep. After about three N ' E24 o ; 20 June years, the first vegetation has now established itself in the water and along the borders the ke. Loc. 14; River 200 m northeast Fiki, Crete; N ' E ; 20 June Loc. 21: River, 1 km west Voleones, Crete; N ' E '; 21 June Loc. 15: Kabanos River, 1 km east Koufi, Crete; N E ; 21 June Loc. 22: River, 500 m west Amari, Crete; This small river is surrounded by forests and its N ' E '; 23 June streambed is dominated by rge stones, resulting locally in small rapids (Figure 8). In general, Loc. 23: River, 100 m east Lambiotes, Crete; however, the river flows quite slowly over most N35 12,978 E ; 23 June its course. The depth the river is variable, with the deepest stretches at least 1.5 m deep. The river is bordered by trees. Large tangles submerged tree roots along the river banks provide an ideal habitat for dragonfly rvae. Loc. 24: Laloumas Reservoir, southeast Skourvou, Crete; N E '; 22 June This artificial ke (Figure 11) about 1.5 km long and at most 0.5 km wide, has been created by Loc. 16: Petres River, 2 km northwest Kaloniktis, at both sides a bridge, Crete; N E ; 19 June 2012, 20 June 2012 and 24 damming the Paridhokefa River, It is characterized by shallow edges with fringes reed, and has only locally aquatic vegetation. June 2012, The Petres River (Figure 9), close to location 15, Loc. 25: Reservoir, 500 m southwest Armanogia, provides a more diverse selection habitats, Crete; N E ; compared to the Kabanos River. The habitat is ten 27 June 2012, quite simir to that in the Kabanos River, but the This retively small ke created in 2009 by Petres River also contains a rge number rocky damming the small Tris Potami River. Due to the very rapids as well as deep and slow-flowing parts with recent formation the ke, aquatic and riparian overhanging trees and submerged roots. Some vegetation (Figure 12) is almost completely absent sections river are fully exposed to the sun, while others are in deep shade. This combination results in suitable habitats for many different dragonfly apart from some fringes the ke is sandy. reed. The substrate species. Loc. 26: Amourgelon Reservoir, 1.5 km southeast Amourgeles, Crete; N35 07,253 E ; 26 Loc. 17: River near Mili, bridge, Crete; N June E ; 19 June Loc. 27: Partira Reservoir, 600 m west Mikri Loc. 18: Pool west Amari Reservoir, west Voleones, Crete; N ' E ; 21 June Episkopi, Crete; N E '; 26 June Loc. 19: Pool north Amari Reservoir, west Loc. 28: Ini Machera Reservoir, northeast Machera, Crete; N E '; Voleones, Crete; N E ; 21 June 26 June Loc. 29: Small river and pools, northeast Demati, Loc. 20: Amari Reservoir, Metochi Chadzigrigori, Crete; N E ; 1.5 km northwest Voleones, Crete; N June 2012, E ; 19 June This artificial ke created in 2009 by damming the Stavromana River (Figure 10). The reservoir is characterised by a sandy substrate, its perimeter gradually sloping to the middle the ke, which Loc. 30; Bramiana Reservoir, 2 km east Kalogeri, Crete; N E ; 27 June

5 Table 1. Records dragonflies, exuviae and rvae on Corfu: adults, exuviae and rvae. This table shows the sum adults (a), exuviae (e) and rvae (l) for each species at each location. Lod Species Loci Lod Loc2 Loc3 Loc4 Loc5 Loc6 Loc7 Loc8 Loc9 LocIO LodO Loc12 Loc11 2 Calopteryx virgo II 11 3e 40a,3e. 40a, Lestes barbarus 8a,64e 8a,64e,+1001 Chalcolestes parvidens 251 Coenagrion puel Coenagrion pulchellum Crocothemis erythraea 2e 4a,2e,+100e, Erythromma lindenii Iio +1 e Erythromma viridulum 2 30a 30a Ischnura elegans,, 16a,1 16a,lie Pyrrhosoma elisabethae 104a,348e,6l Ptycnemis pennipes 8.46e 8,46e 6e 6e 8a, a, a, Aeshna affinis 12e 2e I Anax imperator,15e,15e 4a,13e Anax parthenope,7e Brachytron pratense 1,7e Gomphus schneiderii,37e,2l 65e Onychogomphusforcipatus +100I Somatochlora meridionalis 2\ 21 Libellu depressa,2e,2e 4e, 2,38e Libellu Ubellu fulva 2,53e 4e. Orthetrum brunneum,38e Orthetrumcanceltum 4a 30a Selysiothemis nigra 163e,4l Sympetrum fonscolombii 30a,64e Sympetrum meridionale 40a 40a Sympetrum striotum Sympetrum striotum/ meridionale 53e 367e 301 Trithemis annutaa 9a,180e,1l 9a.180e, 11 Co enagrion intermedium rvae (Figure 19), which were mainly found in C. intermedium (Figure 18) is an endemic submerged vegetation and among submerged species for Crete that has been found at several tree roots. This corresponds very well with the localities on the isnd (JOdicke, 2005; Lopau, description given in JOdicke (2005). 2010). We found the species at six locations, always co-occurring with B. cretensis. This Coenagrion scitulum seems to indicate that they have the same No recent poputions were known for the habitat requirements. The highest numbers c. isnds Corfu and Crete (Lopau, 2010). The intermedium were found at the Kabanos River (loc. 15) and at the Petres River (loc. 16). At the nearest poputions are found on mainnd Greece and on some isnds at less than 100 Kabanos River 50 imagines were observed and km away from Crete or Corfu. We were able to just over 80 exuviae were collected. Atthe Petres find poputions Coenagrion scitulum both River 275 imagines were observed and over 500 on Corfu and Crete. On Corfu C. scitulum exuviae were collected. A short sampling with a scoop net at the tter location revealed over 50 found at some small kes near Roudes (loc. 9) and at a water reservoir near Kavos (loc. Brachytron 15(2): ,

6 88 Species Loc13 Lod 4 Loc15 Loc16 Loc17 Loc18 Loc19 Loc20 Loc21 Loc22 Loc23 Loc24 Loc25 Loc26 Loc27 Loc28 Loc29 Loc30 Calopteryx splendens,4e,23e 200a,50e 20a 30a, 29e,33e Chalcolestes parvidens 12,186e, e 318e 2e 20a 7a,,274e 7a,93e Sympecma fusca Ceriagrion tenellum, e t 50l 20a, 4e 20a, 19e Coenagrion intermedium Coenagrion scitulum 5e Erythromma lindenii +1,000a 8a 40a Erythromma viridulum 24a 30a 1 Ischnura elegans 25e 16e Aeshna mixta 4a,10e Anax imperator 200a 7a,6e Anax parthenope,7e,10 30a.577e,50l 9e 5e, 3e 4a,30e Boyeria cretensis.413e.il, 4e,,2e,20e Lindenia tetraphyl, 2e, Ie 500a, 360e 4a 4a Crocothemis erythraea 30a, 15e Orthetrum brunneum,8e,2e,46e 30a, 13e 1,,25e 6a 8a Orthetrum canceltum, le 60a, 36e,4e,12e Orthetrum coerulescens +1,000a,608e Selysiothemis nigra le 7e 4e 15e 3e Sympetrum fonscolombii Sympetrum meridionale 4a Sympetrum striotum 2e 9e 10e 6e Sympetrum striotum/ meridionale,3e 16a.38e 2, 10,000a. 1,395e a,337e 2, 3e,10e Trithemis annuta Table 2. Records dragonflies, exuviae and rvae on Crete: adults, exuviae and rvae. This table shows the sum adults (a), exuviae (e) and rvae (l) for each species at each location. Species Lod 3 Lod 4 Lod 5 Lod 6 Lod 7 Lod 8 Lod 9 Loc20 Loc21 Loc22 Loc23 Loc24 Loc25 Loc26 Loc27 Loc28 Loc29 Loc30 Calopteryx splendens,4e,23e 200a, 50e 20a 30a, 29e,33e Chalcolestes pan/idens 12,186e, e 318e 2e 20a 7a, Sympecma fusca,274e 7a,93e Ceriagrion tenellum Coenagrion intermedium, 8 27,518e,50l 20a, 4e 20a, 19e Coenagnon scitulum Erythromma lindenii 5e Erythromma viridulum +1,000a 8a 40a Ischnura elegans 24a 30a 1 Aeshna mixta 25e 16e Anax imperator 4a,10e Anax parthenope 200a 7a,6e Boyeria cretensis,7e,10 30a.577e,50l 9e 5e,3e 4a,30e Lindenia tetraphyl.413e,1l, 4e,,2e,20e Crocothemis erythraea,2e, 500a, 360e 4a 4a Orthetrum bmnneum 30a, 15e Orthetmm canceltum.8e,2e,46e 30a, 13e 1,,25e 6a 8a Orthetmm coemlescens, 60a, 36e,4e,12e Selysiothemis nigra +1,000a,608e Sympetrum fonscolombii 7e 4e 15e 3e Sympetrum meridionale Sympetrum striotum 4a Sympetrum striotum/ meridionale 2e 9e 10e 6e Trithemis annute,3e 16a,38e 2, 10,000a, 1,395e +10,000a, 337e 2, 3e,10e

7 Figure 3. Nearly 12). At the overgrown tter successful Corfu. No that it also C. scitulum E ). mating Agia. observed which 24), Therefore species we (1850), location. Since then, on Crete at a the lies are specimens, dam ke 100 km present at that on east the species had found in local Another lindenii. new (Lopau, 2010). a been as but This species Water reservoir Brachytron 15(2): near 2013 Our Erythromma discovered (loc. at popution a as at therefore not unexpected, surprised were rvae and the mainnd Greece discovery were strong a is well known and species on the by exuviae. number high We expect that E. lindenii might be present at other sites on Corfu well. Pyrrhosoma only near few Corfu on 350 rvae. (Figure 13) exuviae Also, river. (Figure many more observed. Larvae Ploeg, the 12). Imagines to and but 2012), study found than only along 15) 100 our P. (loc. 3) a We collected and caught individuals emerging exuviae imagines P. (Brochard findings were elisabethae will & Van make it them in detail and to describe the exuviae. Our results imagines collected & 2006). Lopau, we present this meters and where at the Melissoudi River Sidari, where it nearly six elisabethae pce hundred possible Kavos , we adults, rvae and exuviae had not been described before lindenii for Corfu The water reservoir elisabethae (Lopau, 2010). species popution. present at many sites der Erythromma as rge numbers, fering pro Selys not E. lindenii as well The least therefore considered (Photo: Christophe Brochard). Crete. The by 1) a without reference to the exact anymore and extinct 2012 he observed and first mentioned for Crete & Hagen seen May may conclude poputions very more Agia (N about ten at ovipositing Laloumas (loc. two local After tandem C. scitulum. About a we and but it is rediscovered At this location, photographed month ter, vilge on found here. reproduces north the just scitulum reproduction Crete by Andrew Chambers in ke fering pro nearby Roudes, than 100 years, C. on skin, reproduction individual emerged its rval evidence at the small kes likely pond near Pithos, Corfu (loc. freshly a found next to dune At amply by Lopau the exceed in 1998 Melissoudi the four (Kalkman River (loc. 89

8 Figure 4. Melissoudi Figure 5. Small brook 90 River near Sidari, Corfu (loc. 3), near Drosato (Corfu) habitat Pyrrhosoma elisabethae with concrete culverts in the background (Photo: Christophe Brochard). (loc. 7) (Photo: Christophe Brochard).

9 Figure 6. One the small kes 1 km northwest Poudes, Corfu (loc. 9) (Photo: Christophe Brochard). Figure 7. Water reservoir near Kavos, Corfu (loc. 12) where Selysiothemis nigra is present (Photo: Christophe Brochard). Brachytron 15(2): ,

10 Figure 8. Kabanos River east Koufi, Crete (loc. 15). Habitat Boyeria cretensis and Coenagrion intermedium (Photo: (loc. 16). Habitat Boyeria cretensis and Coenagrion intermedium Christophe Brochard). Figure 9. Petres River, near Christophe Brochard). 92 Kaloniktis, Crete (Photo:

11 Figure Figure 10. Amari 11. Reservoir, Laloumas Metochi Reservoir Chadzigrigori, near Skourvou, northwest Crete Voleones, (loc. 24), Crete locality (loc. 20) (Photo: Christophe Brochard). with a popution Lindenia tetraphyl (Photo: Christophe Brochard). Brachytron 15(2): ,

12 Figure 12. Water reservoir near Armanogia, Crete (loc. 25) in Crete (Photo: Christophe Brochard). 13), P. elisabethae the most common dragonfly species. Accompanying species were Ptycnemis pennipes, Ischnura elegans, Brachytron pratense and Libellu fulva, all other trees (Salix sp. & Alnus sp. for example) are absent, leaving no suitable options for oviposition. P. elisabethae could also not be found at another locality formerly known to hold present in good numbers. Although we looked the species, a river 1.3 km west Episkopiana for P. elisabethae at other potentially suitable (loc. 11). Although L. fulva and P. pennipes habitats on the isnd, we were not able to find were still present, this river also is now probably another popution, indicating that the species too heavily polluted for P. elisabethae. p. might be rare on Corfu. Some locations on Corfu elisabethae is a critically endangered species formerly known to hold P. elisabethae are now (Kalkman et al, 2010). As a consequence, even so heavily polluted by sewage that it seems improbable that they still hold poputions small local changes or modificationsin its habitat have great impact on the global status the this species. Some rivers and small streams species. are densely overgrown by bamboo. Roots Figure 13. Immature female Pyrrhosoma elisabethae, 6 May 2012, Melissoudi River, Corfu (loc. 3) (Photo: Christophe Brochard). 94

13 Boyeria cretensis Gomphus schneiderii B. cretensis (Figure 17) found at seven The rheophile species G. schneiderii found locations on the Isnd Crete. The highest at two localities on Corfu. At a small brook near numbers were observed on the Kabanos Dorsato (loc. 7), three adults, 47 exuviae and River (loc, 15) and the Petres River (loc. 16) where respectively three imagines and 101 exuviae and 30 imagines and 577 exuviae were two rvae were found and at a river southwest Kipriandes (loc. 8) only exuviae (n = 65) were found. observed or collected. Most the sightings imagines concerned patrolling males, Lindenia tetraphyl continuously flying in the shade along the river A newly discovered species and the first banks. Some ovipositing females were also Gomphidae species reported for Crete is observed. Although we focused on collecting exuviae, a brief sampling with a scoop net in the Petres River revealed easily 50 rvae (Figure Lindenia tetraphyl (Boudot 2010). Both exuviae and imagines et al., 2009; Lopau, were found at five 20). These were mainly found in tangles tree kes in the central part the isnd. First, two roots hanging down along the river banks. With exuviae L. tetraphyl were found on 22 June, a very few exceptions, exuviae B. cretensis immediately north the western end the were found in shaded pces, such as tree dam Laloumas Reservoir (loc. 24). Later, an roots and overhanging rocks. The number intensive investigation a rge section the collected exuviae is exceptionally high; historical records give numbers about 200 rvae being collected over a period three years (MOller et al 2012). ke resulted in a total 413 exuviae and one fully grown rva, ready to emerge. On the same day we observed one tandem and more than ten adults. This is an indication that the emerging Figure 14. Female Selysiothemis nigra, Reservoir, 500m Figure 15. Exuviae Pyrrhosoma elisabethae, 6 May southwest Armanogia, Crete (loc. 25), 27 June 2012 (Photo: Christophe Brochard). 2012, Melissoudi River, Corfu (loc. 3) (Photo: Christophe Brochard). B rachytron 15(2): ,

14 Figure 16. Larva Lindenia tetraphyl, 22 June2012, Laloumas Reservoir, Crete (loc. 24) (Photo: ChristopheBrochard). Figure 17. Freshly emergedfemale Boyeria cretensis, 21 June 2012, Kabanos River, Crete (loc. 15) (Photo: Christophe Brochard). 96

15 Figure 18. Male Coenagrion intermedium,21 June2012, Kabanos River, Crete (loc. 15) (Photo: Christophe Brochard). period may be quite long, something which has in these recently created habitats. It is supposed also been noted in Montenegro (De Knijf et al., that the species has a rval life (Figure 16) at 2013). Throughout its range, adults have been least one year (Suhling & Muller, 1996), which observed from March to October, depending on would mean that the species colonised the most the titude (Schorr et al,, 1998). Other pces recently created reservoir within two years after where the species found are a ke near it created. Armanogia (loc. 25), Amourgelon Reservoir (loc. 26), Partira Reservoir (loc. 27) and Ini Machera Reservoir (loc. 28). At all these reservoirs, both adults and exuviae were found, but not as numerous as at Laloumas Reservoir. Of the locations on Crete where L. tetraphyl found, Laloumas Reservoir (loc. 24) produced Somatochlora meridionalis Somatochlorameridionalis is known from a few locations on Corfu (Lopau, 2010). We caught two rvae in a small brook near Drosato (loc. 7). Unlike its congener Somatochlora metallica in Western and Central-Europe, the rvae s. the highest number specimens by far. All meridionalis were found in a very shallow, fast these reservoirs are the result damming small flowing part the stream. rivers and streams, some only a few years ago. The reservoir, 500 m southwest Armanogia Selysiothemis nigra (loc. 25) for example, created in S. nigra found on both Corfu and Crete Surprisingly, L. tetraphyl is already reproducing at only four localities in total. On Corfu, it Figure 19. Larva o/coenagrion intermedium,19 June2012, Petres River, Crete (loc. 16) [Photo: Christophe Brochard). Brachytron 15(2): ,

16 found at one location, namely a water reservoir separate. In G. schneiderii segment six does not near Kavos (loc. 12). At this water reservoir, have teral spines, whereas in G. vulgatissimus 163 exuviae and four rvae were collected teral spines are present on this segment but imagines were not observed. On Crete, (Suhling & MOller, 1996). Based on the absence the species detected at three localities. At a teral spine on both sides segment six, Laloumas Reservoir (loc. 24) over 600 exuviae all 100 collected exuviae Gomphus species were collected, but only a few adults (Figure on Corfu could be identified as G. schneiderii. 14) could be found along the edge the ke. A few hundred metres from the water, adults were present in high numbers on a cornfield, hunting The fact that the eyes G. schneideriiare green in the western part its range, may suggest that a hybrid popution could be present (J.P. for prey and partners. This behaviour also Boudot, pers. comm.). Because eye colour witnessed on Corfu, where no adults were seems not to be a reliable criterion, structural present at the ke. characters should be checked (De Knijf et al, 2013). We also examined the genitalia the Trithemis annuta At some kes on Crete, T. annuta present in exceptionally high numbers, such as at Amah Reservoir (loc. 20), where more than 10,000 adults were seen. Based on the numbers some adults, in order to identify the specimens as either G. Schneiderii or G. vulgatissimus. The genitalia the captured adults appeared to fully comply with those known for G. schneiderii. Furthermore, the exuviae that we examined collected exuviae, this must be considered as a conservative estimate the total number did not show intermediate criteria such as having the teral spine segment six only at individuals. At less than 1% the perimeter one side, or having very small teral spines. the ke, almost 1,400 exuviae were collected. G. vulgatissimus is not known to be present The species also very abundant (>10,000 on Corfu. For these reasons we find it difficult adults) at some other sites, for example at to believe that Gomphus poputions on Corfu Laloumas Reservoir (loc. 24). could be hybrid origin. Nevertheless, more research (e.g. genetical comparison both Discussion Gomphus species) is needed in order to prove or contradict that the popution Corfu belongs Identification Gomphus schneiderii to G. schneiderii.also more research on exuviae Adults G. schneiderii are easily confused is needed in order to define all the identification with the very simir Gomphus vulgatissimus. features for discerning between the exuviae Dijkstra & Lewington (2008) state that one G. vulgatissimus and G. schneiderii. the field characters for the identification G. schneiderii, is the presence blue eyes rather than greenish eyes. However, the three observed adults on Corfu all had greenish eyes Why search for exuviae The results presented in this paper show that estimates the popution size for Odonata (Figure 21) and so resembled G. vulgatissimus. species should not only be based on the This also observed for the specimens found in Montenegro (De Knijf etal, 2013). This could easily lead to confusion and misidentification numbers observed adults, but also on the collection exuviae. For example, a maximum 104 adults P. elisabethae were counted Gomphus species in southeastern Europe. De along the Melissoudi River on Corfu (loc. 3), Knijf et al. (2013) give structural differences to whereas 348 exuviae were found. This location discriminate between both species. Since adults visited three times and the overall count are difficult to identify in the field, exuviae and 104 adults the sum all these visits. rvae may sometimes help in clinching the identification Gomphus species present at a Obviously, this number observed specimens could be unreliable as one individual might have certain location. The exuviae G. schneiderii been recorded more than once. On the other and G. vulgatissimus are retively easy to hand, exuviae were collected on each occasion, 98

17 Figure 20. Larva Boyeria cretensis, 1 9 June2012, Petres River, Crete (loc. 16) (Photo: Christophe Brochard). making double counting impossible. Also on count all adults, but this is also the case when Corfu, at the water reservoir southwest Kavos searching for exuviae. Exuviae are sometimes (loc. 12), 163 exuviae and four rvae S. nigra difficult to find because the rvae might not yet were found, while no adults were observed. have emerged, or the exuviae could have been Of course there is no best way estimating hed or blown away during bad weather. It is a popution size. It is nearly impossible to clear that the most reliable results for estimating Figure 21. Male Gomphus schneiderii with greenish eyes, 10 May 2012, Drosato, Corfu (loc. 7) (Photo: Christophe Brochard). Brachytron 15(2): ,

18 a popution size may be obtained using a combination methods, something which has Christophe Brochard Marsstraat 77 also been proposed by Raebel et al. (2010). 9742EL Groningen Without taking exuviae into consideration, the info@cbrochard.com number B. cretensis and L. tetraphyl would have been greatly underestimated in our survey. Exuviae research is also invaluable where, for whatever reason, adults are hard to find. Ewoud van der Ploeg Suerhfan 60 97S2HD Haren gn Imagines the endemic B. cretensis are not agrius_convoivuli@hotmaii.com easily encountered in the field. We counted a total 30 adults B. cretensis at the Petres River (loc. 16) and some them were probably counted several times. On the other hand, 577 exuviae were collected. The same goes for L. References Battin, T., Überblick über die Libellenfauna der Insel Kreta (Insecta: Odonata). Zeitschrift der Arbeitsgemeinschaft Österr, Entomologen 41: 52-64, tetraphyl on Crete. At Laloumas Reservoir Battin,T, Description the rva Coenagnon (loc. 24) only about ten adults were observed, while 413 exuviae were collected. The first record this species an exuvium rather than a for Crete that sighting an adult specimen. Simir results were obtained for Caliaeschna microstigma (a total 21 exuviae and two imagines) and G. schneiderii (a total intermedium Lobman, 1990 from Crete, Greece (Zygoptera: Coenagrionidae). Odonatologica 20: Boudot, J.P., VJ. Kalkman, M. Azpilicueta Amorin, T. Bogdanovic, A. Cordero Rivera, G. Degabriele, J.-L. Dommanget, S. Ferreira, B. Garrigós, M. Jovic, M. Kotarac, W. Lopau, M. Marinov, N. Mihokovic, E. Riservato, B. Samraoui & W. Schneider, Ats the 102 exuviae and three imagines) on Corfu. We were also able to collect 43 exuviae Aeshna Odonata the Mediterranean Libellu Supplement 9: and North Africa. mixta on Crete, but not even a single observed. adult Brochard, C., D. Groendijk, E. van der Ploeg & T. Termaat, Fotogids Larvenhuidjes van Libellen. KNNV uitgeverij, Zeist. Brochard, C. & E. van der Ploeg, Een eerste Acknowledgements We would like to thank Vincent Kalkman, Fons Peels and Richard Seidenbusch for theiradvice, and Jean-Pierre Boudot for his advice and very kennismaking met de rven van de Turkse koraaljufferen de Griekse vuurjuffer. Brachytron 15(2): De Knijf, G., C. Vanappelghem & H. Demolder, Odonata from Montenegro, with notes on useful comments on this paper. Without their taxonomy, regional diversity and conservation. assistance the trips would not have achieved this success. We want to thankandrew Chambers for allowing us to use his observation Coenagrion scitulum on Crete and publish his discovery in this article. We are very grateful to the Schure- Beijerinck-Popping fund that financed the trip to Corfu and to the Uyttenboogaart-Eliasen Stichting for financialsupport for the trip to Crete. We also thank Antony and Marilyn Guest on Corfu, and Stratos Kapetanaki and his family on Crete, for their hospitality. We wish to sincerely thank David Chelmick for his editing assistance. Finally we would like to thank Geert De Knijf for his advice and the great improvement this paper. Odonatologica 42(1): Dijkstra, K.-D.B., & R. Lewington (illustraties), Libellen van Europa: Veldgids met alle libellen tussen Noordpool en Sahara. Tirion Uitgevers BV, Baarn, druk. Jödicke, R., Bemerkungen zu Coenagrion intermedium (Odonata; Coenagrionidae). Libellu Supplement6; Kalkman, V.J. & W. Lopau, Identification Pyrrhosoma elisabethae with notes on its distribution and habitat (Odonata; Coenagrionidae). International Journal Odonatology 9: Kalkman, V.J., J.-P. Boudot, R. Bernard, K.-J. Conze, G. De Knijf, E. Dyatlova, S. Ferreira, M. Jovic, J. Ott, E. Riservato and G. Sahlen, European Red List Dragonflies. Luxembourg: Publications Office the European Union. Lohmann, H., Coenagrion ponticum intermedium subspec. nov. von der Insel Kreta, Griechennd (Odonata: Coenagrionidae). 100

19 Opuscu Zoologica Fluminensia 54: 1-7. Lopau, W., Studiën zur Libellenfauna Griechennds IV. Libellu Supplement 10: Verhaltensbiologie der Imagines (Odonata: Aeshnidae). Libellu 25: Schorr, M., W. Schneider & H. Dumont, Ecology and distribution Lindenia tetraphyl Müller, O., U. Taron, A. Jansen & T. Schneider, (Insecta, Odonata, Gomphidae): a review Description the rva Boyeria cretensis Peters and comparison with B. irene (Fonscolombe) (Anisoptera: Aeshnidae). Odonatologica 41(1): Peters, G., Die Schattenlibelle auf Kreta International Journal Odonatology 1; Selys Longchamps, E. de & H.-A. Hagen, Revue des Odonates d Europe. Ouvrage servant de complément et de supplément a Monographie des Libellulidées d Europe. (Boyeria cretensis spec. nov.) und die Mémoires de Société royale des Sciences Monophylie der Gattung Boyeria McLachn, (Odonata Anisoptera, Aeshnidae). Deutsche Entomologische Zeitschrift 38: Raebel, E.M, T. Merckx, P. Riordan, D.W. Macdonald, DJ. Thompson, The dragonfly delusion: why it is essential to sample exuviae to avoid biased Journal Insect Conservation surveys. 14: Schneider, T. & O. Müller, Der Endemit Boyeria cretensis: Beobachtungen zur de, Liège 6; l-xii, 1-408, 4 PI. Suhling, F. & O. Müller, Die Flulijungfern Europas (Gomphidae). Die Neue Brehm- Bücherei 628, Magdenburg (Westarp- Wissenschaften). Sutton P.G., A checklist the dragonflies (Odonata) Corfu (Kérkira) including a new record forthe lonian Isnds, the Bck Pennant Selysiothemis nigra (Vander Linden, 1825). Bulletin the Amateur Entomologists Society 68(485): Summary Brochard, C. & E. van der Ploeg, Searching for exuviae endemic Odonata species in Greece. Brachytron 15(2): During two field trips to Greece in 2012, the first to Corfu in May 2012 and the second to Crete in June 2012, 37 species dragonflies were observed. On Corfu, many rvae and exuviae Pyrrhosoma elisabethae were found, both unknown to science. On Crete a fair number exuviae Coenaghon intermedium and Boyeria cretensis were collected. Coenaghon scitulum and Erythromma lindenii are reported for the first time for Corfu and Lindenia tetraphyl a new species the dragonflyfauna Crete. Also on Crete, Coenagrionscitulum is rediscovered at two localities after an apparent absence more than 100 years. The identification Gomphus schneiderii and the use searching for exuviae are discussed near the rval habitat. Samenvatting In dit artikel worden de resultaten besproken van twee reizen naar Griekennd. In mei 2012 werd een bezoek gebracht aan Corfu en in juni 2012 werd Kreta bezocht. Tijdens deze twee reizen werden in totaal 37 soorten libellen Zowel waargenomen. op Corfu als op Kreta werden bijzondere ontdekkingen gedaan.op Corfu werden meer dan 300 rvenhuidjes van de Griekse vuurjuffer (Pyrrhosoma elisabethae) gevonden. Op Kreta werden ruim 600 huidjes verzameld van de Kretawaterjuffer (Coenagrion intermedium) en ongeveer 750 rvenhuidjes van de Kretaschemerlibel (Boyeriacretensis). Naast deze vondsten werden op beide einden soorten ontdekt die er niet eerder zijn aangetrfen. Op Corfu werden de Gaffelwaterjuffer (Coenagrion scitulum ) en de Kanaaljuffer (Erythromma lindenii ) ontdekt. Op Kreta werd de Vaandeldrager (Lindeniatetraphyl) op verschillende patsen aangetrfen.niet alleen is dit eennieuwe soort voor Kreta, het betreft ook de eerste rombout die op het eind is aangetrfen.op Kreta werd ook eentweede kleine poputie van de Gaffelwaterjuffer ontdekt. Keywords: Odonata, Greece, Corfu, Crete, exuviae, rva, Pyrrhosoma elisabethae, Coenagrion intermedium. Coenagrionscitulum, Erythromma lindenii,boyeria cretensis, Gomphus schneiderii, Lindenia tetraphyl. Brachytron 15(2): ,