ANNALES • Ser. hist. nat. • 12 ■ 2002 ■ 2 origina! scientific paper UDC 595.74:591.13:591.5(497.4+497.5-16) received: 2002-10-15 OWL-FLY UBELLOIDES MACARONfUS (SCOPOLI, 1763) IN SLOVENIA AND IN THE NORTHWESTERN PART OF CROATIA (NEUROPTERA: ASCALAPHIDAE) Dušan DEVETAK Department of Biology, University of Maribor, SI-2000 Maribor, Koroška 160 E-mai): Dti5ao.Devetak@uni mb.si Petra PIRŠ SI-2204 Miklavž na Dravskem polju, Taborniška ulico 3, Skoke Franc JANŽEKOVIČ Department of Biology, University of Maribor. SI-2000 Maribor, Koroška 160 ABSTRACT The distribution and biology of the European ascalaphid species Libel loides macaroni us (Scopoli) in Slovenia, Croatian Istria and Quarnero is presented. With the aim to investigate the diet of the owl-fly species, the digestive tract contents were examined. Remains of aphids, bugs, cockroaches, beetles, neuropterans and dipterans were found. Key words: Libelloides macaronius, owl-flies, Neu rooter a, distribution, Slovenia, Istria, Quarnero, phoresy, diet ASCALAFO UBELLOIDES MACARONIUS (SCOPOLI, 1763) IN SLOVENIA, ISTRiA E QUARNERO (NEUROPTERA: ASCALAPHIDAE) S1NTESI L'articolo presenta un resoconto di distribuzione e biologia dell'Ascalafide europeo Libelloides macaronius (Scopoli) in Slovenia, ¡stria e Quarnero. Cli ascalati sono predator: poiifagi che si nutrono di afidi, cimici, scarafaggi, scarabei, neurotteri e dilteri. L'articolo include anche note sulfa predazione di ascalati e sulia forest. Parole chiave: Libelloides macaronius. ascalati, Neuroptera, distribuzione, Slovenia, Istria, Quarnero, fores;, alimentazione 219 ANNALES • Ser. hist. nat. • 12 ■ 2002 ■ 2 DuSan DLVETAK ef. a/.: OWL-FLY UliLLLOIDES MACARONIUS (SCOPOI I, I7(,3] IN SLOVENIA AND IN IIIL NORTIIWFSUKN PART Of CROATIA .... 219-226 INTRODUCTION Owl-flies (Ascalaphidae) are medium-sized to large neuropterans, widely distributed in tropical and subtropical regions. About 400 species in ca. 70 genera are known (Aspóck ef a/., 2001). In Europe, 16 species have been recorded (Aspóck et a/., 2001). In the northwestern part of the Balkan Peninsula, 3 species in 2 genera occur: Deleproctophylla australis (Fabricius, 1787), Libel-loides lacteus (Brullé, 1832) (syn. Libelloides ottomanus /Germar, 1839/) and Libelloides macaronius (Scopoli, 1763) (Aspóck el al, 1980, 2001; Devetak, 1992, 1995, 1996). Libelloides macaronius was described in Scopoli's Entomología carniolica in 1763 as Papilio macaronius. Later, the species was placed in the genus Ascalaphus Fabricius, 1775, and in 1972, Tjeder placed the species in the genus Libelloides Schaffer, 1763. Libelloides macaronius is polycentric Ponto-Mediterranean element known from Central, Eastern and Southern Europe and from the Palearctic region of Asia (Aspóck et al., 1980; 2001). In the Balkan countries, the species is widely distributed (Devetak, 1992). Adult and larval morphology of L. macaronius was thoroughly investigated. According to the high variabil- Pig. 1: Distribution of L. macaronius in Slovenia, Istria and Quarnero based on the owl-flies collected after 1950. SI. 1: Razširjenost metuljčnic L. macaronius v Sloveniji, Istri in v Kvarnerju glede na primerke, zbrane po letu 1950. ity in wing-coloration patterns, a few subspecies were described but their taxonomic status is still uncertain (Aspock et al., 1980, 2001). The larva of L. macaronius was described by Pieper & Wlllmann (1980). Owl-flies are diurnal predators able to fly at high velocities in pursuit of small insects. They grasp their prey in flight using strong legs, and mandibles enable them to feed even on strongly sclerotised insects. From the intestinal contents one can speculate on the food supply of the animal investigated. Since 1965 and 1967, when Gogala & Michieli (1965) and Gogala (1967) published their papers on ultraviolet sensitivity of the ascalaphid superposition eyes, a series of papers elucidating the mechanisms involved in UV vision has been published (for review see Stušek etal., 2000; Drašlar & Wolfrum, 2001; Krai, 2002). This unique sensitivity of the ascalaphid eyes is the reason why the owl-fly species L. macaronius has become a well-known experimental animal (Fig. 2). In the Republic of Slovenia, L. macaronius is treated as endangered species. The aim of our study is to present information on the biology and distribution of the owl-fly in Slovenia and in the northwestern part of Croatia. MATERIAL AND METHODS Dried or in alcohol preserved adults from insect collections in the following Institutions were examined: Natural History Museum of Slovenia (Ljubljana), Slovenian Academy of Science and Art (Ljubljana), Croatian Natural History Museum (Zagreb) and D. Devetak's collection (Maribor). The owl-flies were collected by the following persons: J. Ahtik (JA), ). Carnelutti (JC), A. Če-hid (AČ), D. Devetak (DD), M. Devetak (MD), M. Frank-ovič (MF), V. Furlan (VF), I. Hafner (IH), M. Hafner (MH), F. Janžekovlč (FJ), M. Jež (MJ), M. Kaligarič (MK), K. Kirblš (KK), B. Kmecl (BK), V. Lesjak (VL), I. Lešnik (IL), B. Mencinger (BM), F. Perovicf (FP), P. Pirš (PP), J. Staudacher (JSta), J. Stussiner (JStu), A. Šentjurc (AŠ), P. Tonkli (PT) and M. Zavec (MZ). The wings of the owl-flies from Petrinje and Pomjan were measured and analysed using descriptive statistics. The insects were collected in June and July 1996. To investigate the digestive tract content, 25 adults from Petrinje, preserved in 70% alcohol, were dissected and the intestine was isolated. The masticated food remains suspended in alcohol were mounted on glass slides and examined microscopically. A few preparations were stained with methylene blue. The best results were obtained without staining. In the field, activity of the owl-flies was recorded with the Sony video camera recorder CCD-TR750E. The plant communities of the meadows near Petrinje were documented; for terminology of the species see Mar-tinčič etal. (1999). 220 ANNALES • Ser. hist. nat. • 12 ■ 2002 ■ 2 Duiali DIVFTAK vi. j/..- OW1.-FIY ilRCLLOIDCS MACARONIUS (SCOPOLI. I 70 i) IN SLOVENIA AND IN THE NORIHWFSTFRN PART OF CROATIA .... 219-220 RESULTS Distribution of L. macaronius in the northwestern part of the Balkan Peninsula Literature records: Kačfrek (1998): the island of Krk: Baška, Jurandvor, Malinska, Njivice, Omišalj; TSborsky (1936): the island of Krk; Tdborsky (1939): Šmarna gora. Material examined (for the abbreviations used see Material and methods) (Fig.1): Italy: Trieste/Trst: Villa Opicina/Opčine, 26. VI. 1973 (PT). Slovenia: Ankaran, 27.-29. VII. 1982 (MZ); Bela krajina: Da-melj, 4. VII. 1980 (DD); Bela krajina: Vinica, 5. VII. 1980 (DD); Cerknica, Menišija, 10. VII. 1966 (jO; Fig. 2: Owl-fly LibeUoides macaronius (Scopoli, 1763) in copula. (Photo: T. Makovec) Sl. 2: Metuljcnica LibeUoides macaronius (Scopoli, 1763) med parjenjem. (Foto: T. Makovec) Dragonja, 17. VI. 1996 (DD, FJ, BM, PP); Goričko: Čepinci, 28. VI. 1997 (DD); Haloze: Cirkulane, 29. VI. 1997 (DD); Izola, VI. 1982 (MK); Koper, Srmin, VII. 2002 (MD); Krim, Gornji Ig, 7. VII. 1974 (PT); Kum, 2. VIII. 1918 (MH); Kurešček, Zapotok, 24. VII. 1921 (JStu); the surroundings of Laško, 30. VII. 1970 (IL); Laško, Govce, 6. VII. 1980 (IL); Laško, Šmohor, 11.-14. VII. 1990 (BK); Lisca, 10. VII. 1972 (JA); Ljubljana, along the Sava banks, 18. VI. 1932 (IH); Ludranski vrh, Najevnik (1000 m altitude), 27. VII. 1980 (MJ); Medvode, Preska, 25. VI. 1910, 1. VII. 1923, 29. VI. 1929, 22. VI. 1930 (MH); Nanos, 24. VII. 1983 (AŠ); Petrinje, nad Črnim Kalom, 12. VII. 1974 (DD), 14. VII. 1975 (DD), 16. VI. 1976 (DD), 26. VIII. 1980 (DD), 11. VII. 1982 (DD), 14,18. VI. 1996 (DD, Fj, BM, PP), 20. VII. 1996 (AČ, KK, PP); Pod Stolom, 27. VII. 1919 (MH); Polhograjski Dolomiti: Grmada, 25. VII. 1982 (VF); Polhograjski Dolomiti: Topol, 19. VI. 1932 (JSta); Pomjan, 17. VI. 1996 (DD, F), BM, PP); Sežana, 22. VII. 1981 (DD); Sežana: Povir, 17. VIII. 1982 (DD); Sežana: Štorje, 22. VII. 1981 (DD); Sorško polje, Godeška Dobrava, 10. VI. 1923 (MH); Begunjščica, 10. VIII. 1919 (MH). Croatia - Istria: Kamenjak, 12.-15. VII. 1996 (DD); Limski kanal, 16. VI. 1989 (DD); the island of Fenera, VII. 1996 (DD); Pula, 10.-15. VI. 1979, 6.-8. VII. 1983 (BK, AŠ); Rovinj, 4. VI. 1985 (DD); Rovinj, Valalta, 10. VI. 1988 (DD); Vozilidi, 27. VI. 1974 (FP). Croatia - Quarnero: The island of Cres: Punta Križa, VI. 2002 (DD); the island of Cres, Uvala Banja, 5. VII. 1987 (MF); the island of Krk, Voz-Omišalj, 8. VI. 1938 (JSta); the island of LoŠinj, VI. 1974 (VF), 7. VII. 1974 (PT); the island of Lošinj, Čunski, VII. 1974 (VF, PT), VII. 1987 (VF); the island of Lošinj: Nerezine, VI. 1999, VI. 2001, VI. 2002 (DD); the island of Pag, Caska, 23. VI. 1956, 5. VII. 1960; the island of Pag, Kolansko Blato, 11. VI. 1958; the island of Pag: Novalja, 29. VI. 1955; the island of Pag, Pag, VII. 1960, 15. VI. 1979 (VL); the island of Pag, Zaglav, VI. 1956; the island of Rab, Lopar, 21. VI. 1976 (DD); the island of Susak, 19. VI. 1962; the island of Unije, 4.-7. VII. 1964. Length and width of the wings from Petrinje and Pomjan (Slovenia) Means and standard deviations of length and width of the wings for both sexes and the results of F-test (ANOVA) comparisons of means between sexes are given in Table 1. Means of the males were found to be significantly smaller than in the females. 221 ANNALES • Ser. hist. nat. • 12 • 2002 - 2 Dli5.ni DEVEIAK cl. A I.: OWl-fLY LIBULOIDLS MACARONIUS (SCOPOl.l, 1763) IN SLOVENIA AND IN THE NORTHWESTERN PART OF CROATIA ..., 219-226 Tab. 1: Length una width of the wings of L. macaronius from Petrinje and Pomjan (in millimetres). Tab. 1: Dolžina in širina kril metuljčnic L. macaronius, ujetih v Petrinjah in Pomjanu (v mm). Petrinje Pomjan F-test males n=53 females n=40 males n = 8 females n=13 F),l 12 P forewings length 20.5 ± 0.5 23.5 ±1.0 21.5 ±1.0 23.0 ± 1.0 204.23 <0.0001 width 6.510.5 7.5 ±0.5 7.0 ±0.5 7.5 ±0.5 161.88 <0.0001 hindwings length 17.5 ± 0.5 19.5 ± 1.0 18.0 ± 1.0 19.5 ± 1.0 146.30 <0.0001 width 6.5 ±0.5 7.5 ±0.5 7.0 ± 0.5 7.5 ± 0.5 159.81 <0.0001 Tab. 2: Insect fragments extracted from the digestive tract of L. macaronius. Tab. 2: Delci žuželk iz prebavnega trakta metuljčnic L. macaronius. Insect order / suborder, family structure / body part Blattaria Legs Homoptera: Aphidoidea complete aphids, legs Hemiptera: Heteroptera compound eyes, legs Neuroptera: Chrysopidae Antennae Diptera Legs Coleoptera antennae, mouthparts, chitinous plates The digestive tract content Well-chewed and partially digested insect fragments were found in the digestive tract (Figs. 5-9). In most cases it was impossible to determine the origin of the rest. Fragments of various body parts of different insect orders were found (Tab. 2). From two adults, fragments of plant tissues were isolated (Fig. 10). Remarks on the habitats L. macaronius occurs in meadows, pastures and scrubs. In the Mediterranean part of Slovenia and Croatia, the owl-fly is often found in steppe with Stipa as a dominant grass genus. In the surroundings of Petrinje (Karst edge/KraSki rob), the adults were recorded in two habitats, in a scrub community and in grassland (Fig. 3). In the scrub, the dominant species were Juniperus communis and Stipa pulcherrima, and in grassland the characteristic and dominant species was Bromus erectus. Plant species occurring in the grassland at Petrinje in June 1996 are listed in Table 3. In the Petrinje habitats, insects of fifteen orders were recorded and most of them are a potential prey to L. macaronius. In The Petrinje meadows and scrubs, the following neuropteran species were also collected from low vegetation: Semidalis aleyrodiformis (Stephens), Hemerobius gilvus Stein, H. handschini Tjeder, Chrysoperla lucasina (Lacroix), Chrysopa walkeri McLachlan, Ch. phyllochroma Wesmael, Ch. pallens (Rambur), Dichochrysa abdominalis (Brauer) and D. zelleri (Schneider). Fig. 3: Meadows near Petrinje, June 1996. SI. 3: Travniki v bližini Petrinj, junij 1996. Fig. 4: A nymph of a mite from the family Erytraeidae. Scale bar = 200 pm. SI. 4: Ličinka pršice iz družine Erytraeidae. Merilo = 200 pm. Fig. 5: A cockroach's tarsus with the pectinate claw (order Blattaria). Scale bar = 200 pm. SI. 5: Ščurkov tarzus z glavnikastim krempljem (red Blattaria). Merilo = 200 pm. Fig. 6: Remainder of an aphid (order Hemiptera, Homoptera). Scale bar = 200 pm. SI. 6: Ostanek listne uši (red Hemiptera, Homoptera). Merilo = 200 pm. Fig. 7: A fragment of the antenna (? order Coleóptera). Scale bar = 200 pm. SI. 7: Delček tipalke (1 red Coleóptera). Merilo = 200 pm. Fig. 8: Dipteran tarsal segments; the claws, empodium and pulvilli are recognized (order Díptera). Scale bar = 200 pm. SI. 8: Segmenti tarza dvokrilca, z dobro vidnimi kremplji, empodijem in pulvilli (red Díptera). Merilo = 200 pm. Fig. 9: Corneal lenses of a bug's compound eye (order Heteroptera). Scale bar = 200 pm. SI. 9: Kornealne leče steničinega mrežastega očesa (red Heteroptera). Merilo = 200 pm. Fig. 10: Fragments of plant tissues. Scale bar = 100 pm. SI. 10: Delci rastlinskih tkiv. Merilo =100 pm. 222 _ANNALES • Ser. hist. nat. • 12 ■ 2002 • 2 DuSan DEVETAK et. al.: OWL-FLY LIBELLOIOES MACARUNlUb (SCOPOLI. 1763) IN SLOVENIA AND IN THE NORTHWESTERN PART OF CROATIA . 223 ANNALES ■ Set. hist. nat. • 12 • 2002 ■ 2 Dilian DEVETAK ef. tl.; OWl-lLY LIBULOlors MACARONIUS ISCOPOLI, I/6J! IN SLOVENIA AND IN THE NORTHWESTERN PART OF CROATIA .... 219-226 Tab. 3: A list of plant species in a meadow near Petrinje (June 1996). Tab. 3: Seznam rastlinskih vrst, zabeleženih na travniku pri Petrinjah (junij 1996). Achillea millefolium L.______ Anacamptis pyramidalis tL.) L,C. Rich._ Anihyllis vulneraria L___ _ Brachypoditim pinnatum (L.) P. Beauv._ Bromus ereetus Hucis._ Buphihalmum salkifolium L...................... Cen'a med rupestris L.____ Cotinus coggygria Scop._ CYnandium virKetoxicum (L.) Pers._ Dorycnium gerinanicu/n (Grem I i' Ron v_ Ciynkium amethystinum L._ i Euphorbia cyparissias L._w f'raxinus ornus L._ Galium verurn L.__.. ............. Hellebores muIvfidus Vis._ luniperus communis L._ Knautia illyrica Beck_ Li gust rum vulgare L._ p Urnim lenuifolium L._____ Mel i ca ciliata L._ Pinus nigra Arnold_ Plantago argentea Chaix._ Polygala nicaeensis Risso_ Potent i I la tommasiniana F. Schultz._ Prunus mahaleb L.____________ Kharrmus saxatilis Jacq._ Ross sp.____ Salvia praterisis I._ Sanguisorba minor Scop._ Stipa pulcherrrma C. Koch_ Teucrium montarium 1.._ Jeucrium chamaedrys L_ Thymus longicaulisC. Presl._ Tragopogon tornmasinii C.H. Schultz._ Trinia glauca (L.) Dum. Notes on phoresy and spider predation Phoresy was observed while collecting ascalaphids at Petrinje in June 19%. In one female L. rnacaronius, a nymph of a mite from the family Frytraeidae (Fig. 4) was recorded, clung to the owl-fly's hindleg. Despite of the fact that the owl-flies are predators, they can easily become prey especially when resting on plants, fn the field, they were observed while becoming a prey to birds and spiders. At Petrinje, an owl-ffy male became a victim in june 1996 of an unidentified jumping spider (Salticidae). DISCUSSION Owi-tly Li be I hides rnacaronius is widely distributed in Istria and Quarnero, and occurs also in certain warmer places in Slovenia. This ascalaphid prefers open habitats - meadows, pastures and scrub communities with low bushes. Grassland is inhabited by a number of insects from 15 orders that serve as potential prey of L. rnacaronius- Adults are polyphagous daytime active predators, highly adapted for capturing prey in flight. Ascalaphids are able to prey upon sclerotised insects because of their strong jaws. This ability is contrary to some green lace-wings (Chrysopidae), which are specialised to feed on soft-bodied insects such as aphids (Stelzl, 1991; Stelzl & Devetak, 1999), but resembles the feeding habits of adult antlions (Myrmeieontidae) (Stelzl & Gepp, 1990; Devetak, 1996, 1997). In the digestive tract of L. rnacaronius, fragments of aphids, bugs, cockroaches, beetles, green lacewings and dipterans were recorded. These findings resemble the prey-spectrum in closely related species Libelloides coccajus (Denis & Schiffermuller, 1763), where dipterans, coleopterans and hymenopter-ans are predominant prey (Stelzl, 1991). In both owl-fly species, fragments of plant tissues were also found. This plant material probably originated from the intestinal content of the herbivorous insects captured by the ascalaphids. ACKNOWLEDGEMENTS This study was supported by the Slovene Ministry of the Environment and Spatial Planning and by the Ministry of Education, Science and Sports. We are very grateful to Prof. Dr. Kazimir Tarman (Ljubljana) for identifying a mite and to Prof. Dr. Mitja Kaligaric (University of Maribor) for identifying the plant species from Petrinje. We are grateful to Dr. Sonja Skornik (University of Maribor) for information on the occurrence of the species at Cirkutane. Thanks to ait the collectors for donating the owl-flies. 258 ANNALES • Ser. hist. nat. • 12 • 2002 • 2 OuSar» DEVETA K