HALLE (SAALE ) 2012 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 The family Inocelliidae (Neuropterida: Raphidioptera): A review of present knowledge Horst Aspöck1, Xingyue Liu2, Ulrike Aspöck3 1 Institute of Specific Prophylaxis and Tropical Medicine, Medical Parasitology, Medical University of Vienna 2 Department of Entomology, China Agricultural University, Beijing 3 Natural History Museum Vienna; Department of Evolutionary Biology, University of Vienna Abstract: Die Familie Inocelliidae (Neuropterida: Raphidioptera): Eine Übersicht des gegen- wärtigen Forschungsstandes Die Inocelliidae, eine der beiden Familien der reliktären Insektenordnung Raphidioptera (Kamel­ halsfliegen), erfuhren zuletzt vor 20 Jahren eine zusammenfassende Darstellung. Seither hat sich die Zahl der beschriebenen und als valide anerkannten Arten von 20 auf 31 erhöht, was auf die Entdeckung neuer Arten im südlichen Nordamerika, vor allem aber in Ost­ und Südost­Asien und besonders in China zurückgeht. Damit ergaben sich zugleich neue Informationen über die Biologie, Ökologie, Chorologie und Biogeographie dieser durchwegs seltenen Insekten. Bisher kennt man die Larven von 12 Spezies, sie sind durchwegs kortikol. Die Larvalperiode umfasst mindestens zwei, zumeist mehrere (bis sieben) Jahre. Das Paarungsverhalten und die Art der Kopulation wurden bei mehreren Arten studiert; es bestehen markante Unterschiede gegenüber den Raphidiiden. Fossile Inocelliiden sind aus dem Eozän, Oligozän und Miozän bekannt, vermutlich hat die Familie – als einer der an winterliche Kälte und damit an gemäßigte Zonen adaptierten Zweige – bereits vor dem K/T­Impakt (der zu einer Beinahe­Auslöschung der Raphidiopteren führte) existiert. Die Verbreitung der Inocelliidae umfasst bestimmte arboreale Teile der Paläarktis und der Ne- arktis. In der Nearktis beschränkt sie sich auf südwestliche und südliche Teile Nordamerikas. Sie ist insgesamt ähnlich jener der Raphidiidae, jedoch etwas kleiner. Es ist bemerkenswert, dass Inocelliiden in einem Großteil der Gebirge Zentralasiens (wo zahlreiche Raphidiiden­ Spezies vorkommen) fehlen. Hingegen stellen sie sowohl in Amerika als auch in Asien die südlichsten Vorkommen der Raphidiopteren dar. Die Suche nach Inocelliiden in großen Höhen in noch weiter südlich gelegenen Gebirgen erscheint erfolgversprechend. Zukünftige Arbeiten werden besonders auch die Klärung der phylogenetischen Beziehungen der sieben Gattungen auf molekularbiologischer Basis zum Ziel haben. Keywords: Raphidioptera, Inocelliidae, review, systematics, species list, phylogeny, biology, chorology, biogeography. H. Aspöck, Institute of Specific Prophylaxis and Tropical Medicine, Medical Parasitology, Medical University of Vienna, Kinderspitalgasse 15, 1095 Vienna, Austria; E­Mail: [email protected] X. Y. Liu, Department of Entomology, China Agricultural University, Beijing 100193, China, E­Mail: [email protected] U. Aspöck, Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria; Department of Evolutionary Biology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria, E­Mail: ulrike.aspoeck@nhm­wien.ac.at 565 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 HALLE (SAALE ) 2012 Introductory remarks The Inocelliidae (Figs. 1, 2, 3, 4) is one of the two families of the endopterygotan insect order Raphidioptera (=snakeflies). Raphidioptera is one of the smallest insect orders comprising altogether about 230 valid and clearly characterized species, 31 of which belong to the family Inocelliidae. In the Mesozoic, Raphidioptera experienced a period of flowering; they occurred in several families with many species and extended into tropical zones and the Southern Hemisphere. It is assumed that Raphidioptera almost became extinct during the period after the K/T­impact (H. ASPÖCK 1998). Since the beginning of the Cenozoic, however, only two families are known to exist, Raphidiidae and Inocelliidae, both of which are adapted to a cold climate. Possibly, the ability to persist throughout cold seasons was a prerequisite for the survival of these lines of snakeflies after theK/T ­impact (H. ASPÖCK & U. ASPÖCK 2009). The latest comprehensive review on the Inocelliidae was published in our monograph 20 years ago (H. ASPÖCK & al. 1991). During the past two decades a number of publications devoted to Inocelliidae has appeared with a considerable amount of new information on taxonomy, biology, chorology and biogeography (see references). Thus, a review of the present state of knowledge seems useful. History of research LINNAEUS (1758) described the first snakefly, a Raphidiid, and it was not until 1781 when an additional valid species of this family was described. In 1832 the first representative of the present­day Inocelliidae was described from Silesia (at that time a province in the east of Germany) as Raphidia crassicornis by SCHU mm EL (1832) and shortly thereafter transferred to a new subgenus, Inocellia, by SCHNEI D ER (1843). Subsequently, Inocellia was raised to a genus, later to a tribe (Inocelliini) and finally to a family (for details see H. ASPÖCK & al. 1991). Fig. 5 shows the progress in the discovery of Inocelliidae over the past 180 years. In the course of the past century, five more valid genera (and two subgenera) were described with altogether 31 valid species (Tab 1): Fibla NAVÁS , 1915 (including the subgenus Reisserella H.A. & U.A., 1971), Negha NAVÁS , 1916, Parainocellia H.A. & U.A., 1968 (including the subgenus Armurinocellia H.A. & U.A., 1973, which was later elevated to the rank of a genus), Indianoinocellia U.A. & H.A., 1970, and Sininocellia YAN G , 1985. In a recent paper (U. ASPÖCK & al. 2011), four more species will be described from Thailand, thus uncovering a new, unknown and probably very important evolution center of the family in Southeast Asia. Taxonomy All known species are morphologically well investigated and characterized. The differentiation of the genera is based, at least in part, on eidonomic characters (mainly head, antennae, wings and wing venation, size), but for the identification of species, characters of the genital structures, preferably of the male genitalia, are essential. Of the 31 described species (plus one subscpecies), 26 are known in both sexes, 4 species are known in the male sex only and 2 species only in the female sex (Tab. 1). The wings are translucent as in all Raphidiidae. Recently, however, a spectacular species, Inocellia elegans (Fig. 6), which is isolated in the genus, was described with large, dark patches on fore and hind wings (LIU & al. 2009b). Keys are available for the identification of all species (H. ASPÖCK & al. 1991, U. ASPÖCK & H. ASPÖCK 1999b, LIU & al. 2009a, 2010a, b). Currently, only few genomic data for a small number of species are available (HARIN G & al. 2011). Biology and Ecology As far as we know, larvae of all species of Inocelliidae develop under bark of trees; one very unusual exception is Parainocellia bicolor which also develops on old grapevines, where it may act as a predator of pest insects (PANTALEONI 1990, 2007). At present, the larvae of only 12 species (plus one subspecies) are known, but all adults have been found on or around trees so that the conclusion is justifiable that development takes place exclusively under bark. In the northern parts of their distribution, Inocelliidae may be found from sea level to almost the timberline. In the southern parts, they are apparently confined to higher altitudes, usually above 1,000 m, e.g. up to 1,700 m (Mexico) and up to 2,600 m (India). 566 HALLE (SAALE ) 2012 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 Fig. 1: Inocellia crassicornis SCHU M ., male (Austria, Eichkogel near Vienna). Length of forewing: 9.5 mm. (Orig., F. Anderle phot.) Fig. 2: Fibla (Reisserella) pasiphae H.A. & U.A., male (Crete, Omalos). Length of forewing: 15 mm. (Orig., H. Aspöck phot.) Fig. 3: Fibla (Reisserella) pasiphae H.A. & U.A., larva (Crete, Omalos). Length of larva: 23 mm. (Orig., F. Anderle phot.). Fig. 4: Fibla (Reisserella) pasiphae H.A. & U.A., pupa (Crete, Omalos). Length of pupa: 25 mm. (Orig., F. Anderle phot.) 567 MITT . DTSCH . GES . ALL G . AN G EW . ENT . 18 HALLE (SAALE ) 2012 The larval period lasts at least two years, but in many species it is apparently much longer, up to four, five, six or (at least in captivity) seven years, and possibly longer. The number of larval stages is around ten, but it is not fixed and may (particularly in case of long development) reach 15 instars. Hard data are, however, not available. Larvae of Inocelliidae are entomophagous, feeding on any small, soft­ bodied arthropods (e.g. aphids, caterpillars, larvae of beetles and small maggots). According to our information, all snakeflies (Inocelliidae as well as Raphidiidae) need a cold snap in winter; otherwise they will not develop adequately and will not pupate. It is, however, not known how long this period must last and at what temperature. In the species of the Old World, pupation takes place in spring and adults appear (after two or three weeks of a pupal stage) in May or June. In the species of the New World, in particular those of the genus Indianoinocellia, pupation takes place at nearly any time of the year since adults have been found from February to September. Adults of Inocelliidae are (in contrast to Raphidiidae) not predators; when dissecting adult specimens, pollen is sometimes found in the gut; but usually the gut is entirely empty so that one may conclude that they take up no food at all. Lifespan of adults lasts only several days and in males is shorter than in females. The mating behavior of Inocelliidae differs considerably from that in Raphidiidae (U. ASPÖCK & al. 1995, U. ASPÖCK & H. ASPÖCK 1999a; H. ASPÖCK 2002, PANTALEONI 2007). The male crawls beneath the abdomen of the female, then attaches his head by eversible sacs emerging from the basis of the antennae to the 5th sternite of the female and finally bends his abdomen so that the 9th gonocoxites of the male can grasp the abdomen of the female. This mating behavior has been observed in phylogenetically distant genera of Inocelliidae; most probably it is characteristic for the whole family thus representing a synapomorphy of the Inocelliidae.