REVISION OF THE (DIPTERA: SYRPHIDAE) FROM THE AZORES ARCHIPELAGO WITH NOTES ON MACARONESIAN SYRPHID FAUNA

S. ROJO, P.M. ISIDRO, C. PEREZ-B~ON& M.A. MARCOS-GARc~A

ROJO, S., P.M. ISJDRO, C. PEREZ-BAR~N& M.A. MARCOS-GARC~A1997. Revision of the hoverflies (Diptera: Syrphidae) from the Azores archipelago with notes on Macaronesian syrphid fauna. Arquipdago. Life and Marine Sciences 15A: 65-82. Ponta Delgada. ISSN 0873-4704.

A revision and taxonomic update of the Syrphidae (Diptera) known in the Azores archipelago is provided. Data about larval feeding, environment preference and flight period are also given. The percentage of endemism is about 9% out of twenty three species. The most common hoverflies are tenax, aeneus, balteatus, corollae, scripta and segnis. Regarding the larval biology, the rate of predacious and saprophagous species is similar to continental Mediterranean ecosystems although the proportion of phytophagous larvae is much lower. The Palaearctic influence is more important in the Azores than in other Macaronesian islands. According to our data, the four Macaronesian archipelagos have only three species in common: , and Eupeodes corollae. Cape Verde, the Canaries and Madeira have two species in common: Ischiodon aegyptius and albornaculata. A check-list of all Macaronesian syrphids and an for Azorean species are also included.

ROJO, S., P.M. ISJDRO, C. PEREZ-~fid~& M.A. MARCOS-GARC~A1997. Revisgo dos sirfideos (Diptera: Syrphidae) do arquipklago dos Aqores, incluindo notas sobre a sirfidofauna macaron6sica. Arquip6lago. CiCncias Biol6gicas e Marinhas 15A: 65-82. Ponta Delgada. ISSN 0873-4704.

Neste trabalho apresenta-se uma revis30 e actualizaclo taxon6mica das espCcies da familia Syrphidae (Diptera) conhecidas para os Acores. Sb,tambCm, apresentados dados sobre alimentagb de , preferencias ambientais e period0 de voo. Num total de vinte e tres espCcies encontradas, a percentagem de endemismos foi de 9%. As especies de sirfideos mais comuns sFio Eristalis tenax, Eristalinus aeneus, Episyrphus balteatus, Eupeodes corollae, e . Quanto i3 biologia, a relag30 entre especies predadoras e sapr6fagas B semelhante i3 do MediterrPneo continental, contudo a proporcgo de fit6fagas C bastante mais baixa. A influencia do Paleartico C bastante mais importante nos Agores do que noutras ilhas MacaronBsicas. De acordo com os dados, os quatro arquipilagos MacaronCsicos apenas possuem tr&s espCcies em comum: Eristalis tenax, Eristalinus aeneus and Eupeodes corollae. Cabo-Verde, Canhias e Madeira possuem duas espgcies em comum: Ischiodon aegyptius and Scaeva albomaculata. E tamb6m apresentada uma "check-list" de todos os sirfideos da MacaronBsia e uma chave de identificagiio para as espBcies dos Agores.

Santos Rojo (e-mail: [email protected].~a.es),P.M. Isidro, C. Perez-BaEh & &. Angeles Marcos-Garcia, Dpto. Ciencias Ambientales y Recursos Naturales, Unidad de Entornologia, Apdo. 99, ES-03080, Alicante, . INTRODUCTION MATERIAL AND METHODS

Adult syrphids, known as hoverflies or flowerflies. are among the most abundant and conspicuous of Diptera. In there are about The Azores archipelago is situated in the Atlantic 1200 species and some 6000 species exist Ocean between 36" 55' and 39" 42' N latitude and worldwide, found in every geographical region between 25" and 31" 30' W longitude. It is except the Antarctic (ROTHERAY1993). Most composed of nine islands of volcanic origin, in species are flower visiting and certain European three groups: two islands form the western group species migrate over very long distances (AUBERT (Flores, Corvo), five represent the younger central et al. 1976). Images use both and as group (Faial, Pico, S5o Jorge, Graciosa and a food supply and females as a source of protein Terceira), and two make up the older eastern vital to egg maturation, some species being group (S8o Miguel, Santa Maria). Distances to significant (HIPPA& KOPONEN1976), the mainland vary from 1,378 km for Santa Maria and active agents in biological control to 1,889 km for Flores. The total area of the (ANKERSMITet al. 1986). The larvae of these archipelago is 2304 km2 and the highest altitude is Diptera can be found throughout the year in a on Pico (2351 m). wide variety of (phytophagous, Geological conditions for the Azorean predacious, saprophagous, saproxylic, vegetation are rather uniform. Basaltic rock mycophagous, etc.), being used as bio-indicators predominates and traquita is also present in zones of site quality such as nature reserve assessment of eruption, offering the chemical conditions (SPEIGHT1986), or future areas for protection very little bases for differentiation of the (MARCOS-GARC~A & GALANTE 1989; vegetation (SJOGREN1973). The islands were RARENDREGT1994) and as an -test of once covered with evergreen forests. These, insecticide effects (HASSAN1989). together with those of the Canaries and Madeira, The study of syrphids in the archipelago has are considered relicts from the Tertiary forests of been poor and unconnected. The first data of southern Europe (TUTIN 1953). The antiquity of syrphid fauna from the Azores, result from the vegetation is reflected in eight of the eleven expeditions by L. Chopard and A. Mtquignon in native trees being endemic to the Azores and two 1930 and R. Frey in 1938. No more data exist other species being endemic to the Azores and until the papers of GOMES(1980, 1982) where Madeira. The Azores islands have only about 300 this author includes the results of two natural plant species but 816 more have been aphidological expeditions by F. A. Ilharco during introduced by man in the last 50 years. The the years 1967 and 1979 and other specimens from endemic rate is about 23% and many of them are private collections. Since these works, excluding restricted to the montane forest (HAGGAR1988; some isolated data appearing in non-specific DIAS 1994). papers, there have been no new contributions to The archipelago has an oceanic climate, the knowledge of this goup of . progressively wetter moving towards the west and The objectives of this work are: a) to review with small variations of temperature and water all published data of syrphid species from the regimen and high levels of precipitation and high Azores Islands, b) to summarise and complete air humidity. The mean annual temperature is this information providing data about the biology, about 17S°C. Frosts are rare below 600 m but ecology and corology of these species, c) to night frosts can occur all year round at altitudes elaborate a key for the identification of the above 1600 m. The precipitation is about 1000 mm Azorean species of Syrphidae and d) a annually at sea level, increasing about 25% for biogeographical analysis of the syrphid fauna. every 100 m increase in altitude (SJOGREN1973). Flores (143 km'): Ae Aeroporto In order to complete the catalogue of the syrphids A1 Alagoas species present in the Azores archipelago, we CS Caldeira Seca obtained all the faunistic citations published in Ce Cedros SBGUY(1936), FREY(1945), GOMES(1980, 1982) FG Faj5 Grande and CRUZ DE BOELPAEPE(1991). Similar, to FS C Fazenda de Santa Cruz complete the knowledge of the geographic M Mat0 distribution of syrphid species in other MF Miradouro da Faj3zinha Macaronesian islands, we have also consulted the PDe Ponta Delgada revisions of Madeira (GOMES& BAEZ 1990), PR Ponta Ruiva Canaries (BAEz 1977~1, b; 1982a; 1986; RB Ribeira Borquieros CLAUSSEN198 1) and Cape Verde (CLAUSSEN& RCz Ribeira da Cruz BARKEMEYER1987). RFz Ribeira Fazenda RdB Rocha dos BordBes SCF Santa Cruz das Flores SCM Santa Cruz Monte SCz Santa Cruz During the last two weeks of September 1995, we SM Santa Maria sampled on S50 Miguel island looking for Va Vales hoverflies in several habitats. With all these data we made the check-list of Graciosa (60 km'): all syrphid species known on the 9 islands in the Cd Caldeira Azores archipelago. We include the updated names of syrphids mainly according to: PECK Pico (433 km": (1988), ROTHERAY& GILBERT (1989) and LC Lagoa do Caiado VOCKEROTH(1986, 1990). In the species Md Madalena accounts we indicate some aspects of the S Silveira identification, geographical distribution (with remarks to Macaronesia), preferred environment, Santa Maria (97 km'): flight period, preferred habitats and other aspects AP Alto do Pico of biology. The details of localities where each A Alto species was cited are also included. Aj Anjos List of abbreviations concerning localities and F Fontinhas papers used in the compilation of records: G Ginjal ME Miradouro do Espigiio PSP Pedras de S5o Pedro Corvo (17 km": Pa Praia Ca Caldeira SP SZo Pedro VC Vila do Corvo VP Vila do Porto VN Vila Nova SCo Jorge (238 km'): Faial (170 km": C Calheta C1 Caldeira IT IlhCu do Topo Fe Feteira LCh Lagoa do Calheta H Horta RS Ribeira do Salto P Pedregulho RF Ribeira Funda RCa Ribeira do Capo RE Ribeira Escabra SCo Miguel(747 km2): RFI Ribeira Flamengos AA Agua de Alto Ba Barrosa RESULTS CM ChFi do Marcela Car CarvFio Bacclza elongata (Fabricius, 1775) FC FajFi de Cima Fenais da Luz FL Adults are an unmistakably slender and elongated FRG Furnas da Ribeira Grande species (at narrowest, no wider than Fu Furnas scutellum). Only two European species of this Ginetes Gi are recognised: Baccha elongara and Grota das Pedras GP Baccha obscuripennis Meigen, 1822. However, Gr Gorreana most authors think that only one single variable LCa Lagoa do Canario species is involved (SPEIGHT& LUCAS1992). LC0 Lagoa do Congo D~STRIBUTION AND BIOLOGY:EuroSiberian and LF Lagoa do Fogo Nearctic species. In the Macaronesian islands LFu Lagoa Furnas only cited in the Azores. Adults are common in PC Pico Castanheiro forests, also in scrub woodland and often flying in PCr Pico de CarvFio the shade under trees or along woodland margins. PV Pico da Vara is associated with a range of Ponta Delgada PDl ground layer in shaded sites (ROTHERAY RG Ribeira Grande 1993). RQ Ribeira Quente FLIGHTPERIOD: April to October. SR San Roque ACTUAL STATUS: Since 1930 only one finding of SI Santa Iria Baccha elongata has been recorded in the Azores SAP Serra da Agua de Pau archipelago. SEGUY(1936) identified this material SC Sete Cidades and since then no more individuals have been detected or cited in the bibliography. It is Terceira (397 kd): necessary to confirm the presence of this species Ac Achada with new material. AS Agualva LOCALITIES:SFio Miguel: Fu,VIII-IX 1930-SG. AH Angra do Heroismo An Angra B Bagacina Chrysotoxum intermedium Meigen, 1822 CGM Caldeira de Guilherme Moniz Fn Furnas The genus Chrysotoxum can be easily identified Ft Feteira because the adults have very long antennae that MS Miradouro da Serreta point forwards. The characteristic feature of MB Monte Brazil Chrysotoxum intermedium is that the length of the PVe Pau Velho 3rd antenna1 segment is equal to or longer than Pe Peneireiro 1st plus 2nd (STUBBS& FALK1993). PVi Praia da Victoria DISTRIBUTIONAND BIOLOGY:Palaearctic species R Riviera found primarily in southern Europe (abundant in SB Santa Barbara the Mediterranean area). In Macaronesian only SA St.' Amaro cited from the Azores. This species is a very good mimic. Chrysotoxum intermedium is usually SG SEGUY1936 common in forest or open habitats with dry soil FR FREY 1945 and flies fast and low, over ground vegetation. GO COMES1980 The is undescribed and its precise feeding GM GOMES 1982 habits are unknown but probably related to root- cz CRUZDE BOELPAEPE 1991 aphids and ants (ROTHERAY & GILBERT1989). OD Own Data (1995) FLIGHTPERIOD: March to October. ACTUALSTATUS: The only data on the presence OD; Car, 24-IX-1995, l ?-OD; CM, IX 1979- of this species in the Azores archipelago, is a GM; FL, VI 1979-GM; FRG, X 1979-GO; Fu: single specimen on SBo Miguel island in 1930. VIII-IX 1930-SG; V+VIII 1938-FR; X 1979-GO; LOCALITIES:SBo Miguel: Fu, VIII-IX 1930-SG. Gi, V 1967-GM; Gr, X 1979-GO; 29-IX-1995, 5 d d 2 9 9 -OD; LCo, V 1938-FR; LCa, 24-IX- Episyrplzus balteatus (De Geer, 1776) 1995, 18 2 P P -OD; PCr, 24-IX-1995, 2 9 0 - OD; PDI: V 1938-FR; X 1979-GO; V 1967-GM; V 1969-GM; SC, VIII-IX 1930-SG; SI, X 1979- This hoverfly has a unique and distinctive GO; SR, V 1938-FR; without locality, VII-VITI abdominal pattern with an upper and lower black 1990-CZ. Terceira: AH: VI 1938-FR; X 1978- band on tergites 3 and 4. However, the upper GM; Ft, V 1967-GM; MB: V 1938-FR; VIII-IX band is sometimes divided into a pair of narrow 1930-SG; MS, VI 1967-GM; PVe, XI 1978-GM; stripes while dark forms have the lateral margins SA, V 1967-GM. of tergites darkened. Episyrphus balteatus is the only species of this genus in Europe. DISTRI~UTIONAND BIOLOGY:This hoverfly is Eristalinus aenezts (Scopoli, 1763) present in Palaearctic, Oriental and Oceanic regions and in Macaronesia has been cited in the The body of this species is typically glossy black Canaries, Madeira and the Azores. Episyrphus or greenish bronze. The spotted eyes are very balteatus shows a wide range of environmental distinctive but to ensure identification it is preferences, being ubiquitous and abundant in necessary to check that only the upper surface of most habitats including highly anthropogenic the eyes is hairy. areas. It is a polyvoltine species with a very wide DISTRIBUTION AND BIOLOGY:Eristalir7us neimts range of -prey. For this reason it has been is present in all continents except in the investigated as a potential biological control for Neotropical region. It is very abundant in the aphids on cereal and other crops (WNUK1977; Mediterranean area (DIRICKX1994). This species ANKERSMIT et a]. 1986) lives on all the islands of Macaronesia but its FLIGHTPERIOD: February to November in North presence on Madeira may be a recent introduction Europe but present all year round in the South. (GOMES & BAEZ 1990). The ecology of this Overwinters as an adult (females) hibernating in species is related to rock pools containing caves, holes in trees etc. Obligatory migrant from decaying seaweed and salt marshes. It is a typical southern Europe in the spring and reaches the coastal species and the larvae live in wet decaying north in the summer, but in the re- vegetation. migrates south (ROTHERAY1993). FLIGHT PERIOD: April to September but this ACTUALSTATUS: This species is probably one of period is probably longer in the Azores islands the most abundant syrphid species in the Azores. related to the hibernating habits of the adults. Except on Graciosa and Corvo, Episyrplzus ACTUALSTATUS: This species has been cited in balteatus has been observed on all the islands and three islands of the archipelago but its presence in is probably active all year, even though it has Flores and Santa Maria shows that it is probably been cited only from May to November in the also present on the other islands. literature. LOCALITIES:Flores: SCz, VI 1938-FR. Santa LOCALITIES:Faial: C1, VII 1938-FR; Fe, VI 1967- Maria: Aj, IX 1979-GO; G, IX 1979-GO. SBO GM; RF1, VII 1938-FR. Flores: Ae, IX 1979-GO; Miguel: PDI: V 1938-FR; IX 1979-GO; RG, V PDe, IX 1979-GO; PR, IX 1979-GO; RFz, VI 1938-FR; SR, VII 1938-FR. 1938-FR; SCF, IX 1979-GO; SCM, VI 1938-FR; SM, IX 1979-GO; Va, VI 1938-FR. Pico: S, VII 1938-FR. Santa Maria: A, VI 1979-GO; PSP, IX Eristalis arbustorum (Linnaeus, 1758) 1979-GO; SP, IX 1979-GO; VP, IX 1979-GO. SBo Jorge: C, VI 1938-FR; RF, VI 1938-FR; RS, The best characteristic for distinguishing this VI 1938-FR. SBo Miguel: Ba, 27-IX-1995, 3 d d- species is the completely dusted face but sometimes it is necessary to use the male to North-West America and is now abundant terminalia. The pattern on the abdomen is very in all the continent. The same process occurred in variable and individuals reared at low New Zealand in about 1888 (GILBERT1986). It is temperatures are darker (even completely black) present in all the Macaronesian islands. Eristalis than those in high temperatures (HEAL1981). tenax is an anthropogenic and almost ubiquitous DISTRIBUTIONAND BIOLOGY: Holarctic region hoverfly species. The larva is found in a wide including and reaching North . range of aqueous and semiaqueous habitats with This species is not present in the Canaries nor in organic materials, polluted ditches, compost, Madeira. Eristalis arbustorum is abundant in cow-dung etc. The larval stages have been many anthropogenic environments. The larvae are described by many authors. This species is saprophagous aquatic or subaquatic, occurring in probably the most important hoverfly from a pools and ponds polluted with dung, stagnant point of view (FERRAZZI & water, farm yards etc. The adult has an important MARLETTO1990) and possesses morphological role as a of some plants (KRANNITZ& adaptations for collection of pollen (HOLLOWAY MAUN1991). 1976). FLIGHT PERIOD: April to October. The adult is FLIGHT PERIOD: February to November. Both more or less constantly present from spring to males and females hibernate but if the winter is autumn because of a series of overlapping not very cold, they can be active all year round. generations (SPEIGHT& LUCAS 1992). This Eristalis tenax is a highly migratory species species disperses away from its breeding sites and (AUBERTet al. 1976). has been collected migrating over an alpine pass ACTUALSTATUS: Cited in all the islands except (AUBERTet al. 1976). Corvo and Graciosa but undoubtedly could also ACTUALSTATUS: In spite of E. arbustorum only be present in these islands. having been cited in 4 islands, this species is LOCALITIES:Faial: C1, VII 1938-FR. Flores: CS, probably present in all the islands of the VI 1938-FR; FG, IX 1979-GO; RFz, VI 1979- archipelago. GO; SCF, IX 1979-GO; SCz, VI 1938-FR; Va, LOCALITIES:Flores: Ae, IX 1979-GO; FG, IX VI 1938-FR. Pico: S, VII 1938-FR. Santa Maria: 1979-GO; SCF, IX 1979-GO; Va, V 1938-FR. AP, IX 1979-GO; G, IX 1979-GO; VP, IX 1979- Santa Maria: AP, IX 1979-GO; Aj, IX 1979-GO; GO. SBo Jorge: LCh, VI 1938-FR. SBo Miguel: G, IX 1979-GO; PSP, IX 1979-GO; SP, IX 1979- Ba, 27-IX-1995, Id 1 ?-OD; Car, 24-IX-1995, GO; VP, IX 1979-GO. SBo Miguel: Ba, 27-IX- 1 ?-OD; Fu, VIII-IX 1930-SG; LCa, 24-IX-1995, 1995, 26 d 2QP-OD; Car, 24-IX-1995, 38d 1 ?-OD; LF, VIII 1938-FR; PDI: V 1938-FR; IX- 1 Q -OD; Fu, VITI-IX 1930-SG; Gr, 29-IX-1995, X 1979-GO; VIII-IX 1930-SG; RG: X 1979-GO; 1 9 -OD; LCa, 24-IX-1995, 2 Q P -OD; PCr, 24- 26-IX-1995, 10-OD; SR, V 1938-FR. Terceira: IX-1995, 28d 28 Q-OD; PDI: VIII-IX 1930- AH, V-VI 1938-FR; MB: V 1938-FR; VIII-IX SG; V+VII 1938-FR; X 1979-GO; RG, 26-IX- 1930-SG; SB, VI 1938-FR. 1995, 6 8 Q -OD. Terceira: MB, V 1938-FR. amoenus Loew, 1848 Eristalis tenax (Linnaeus, 1758) There are at least 140 species belonging to the This common species is a very good mimic of genus Eumerus in the Palaearctic region (PECK drones (male hive ). Other species of the 1988) but the taxonomic status and nomenclature genus Eristalis are similar to E. tenax but the of most of them are confused (SPEIGHT& LUCAS presence of dark front tarsi and very broad black 1992). facial stripe are typical of this (STUBBS& DISTRIBUTIONAND BIOLOGY:Eumerus amoeraus FALK 1993). occurs from southern Europe and North Africa to DISTRIBUTION AND BIOLOGY: Cosmopolitan, Central Asia and Mongolia. It has been cited from known from all biogeographical regions except the Canaries and the Azores but not from the Antarctic. In about 1870, E. terzax spread via Madeira. This species is one of the most abundant species of the genus Eumerus in the 1979-GO; SCz, VI 1938-FR. Pico: Md, VII 1938- Mediterranean Region (DIRICKX1994). Few data FR. Santa Maria: PSP, IX 1979-GO; VP, IX exist on the biology of this species but the larvae 1979-GO; without locality, V 1967-GO. SBo probably live on rotting bulbs and roots. The Jorge: C, VI 1938-FR. SBo Miguel: FC, VTI 1979- larval stages are not described. GM; Fu, VIII-IX 1930-SG; PC, V 1938-FR; PDI: ACTUALSTATUS: Cited by SEGUY(1936) and V 1967-GM, V+VII 1979-GM, V 1938-FR; SR, COMES(1980) from SBo Miguel and Santa Maria V+VII 1938-FR. Terceira: AH, V 1967-GM; B, V islands. The latter author thinks that the record 1938-FR; CGM, X 1978-GM; Ft, V 1967-GM; from Corvo by FREY (1945) may be Eumerus MB: VIII-IX 1930-SG; V 1938-FR; Pe, VI 1967- strigatus. More studies are necessary to confirm GM; PVi, VI 1938-FR; R, V 1967-GM. the presence of E. strigatus in the Azores. Eumerus strigatus has be& introduced in many Melanostoma mellinum (Linnaeus, 1758) countries by the importation of bulbs and vegetables. LOCALITIES:SBo Miguel: PDl, VIII-IX 1930-SG. Males and females of Melanosroma inellinuriz Corvo: VN, VI 1938-FR. Santa Maria: AP, IX have a black face and a short abdomen with 1979-GO. yellow spots of distinctive orientation. It is very common for melanic females to appear. DISTRIBUTIONAND BIOLOGY: This Holarcric Eupeodes corollae (Fabricius, 1794) species is abundant in the Mediterrancan Region. It is present in Madeira (COMES& BAEZ 1990) This species is one of the most common aphid- and old records from the Azores and the Canaries killing hoverfly species in the Palaearctic region. exist. Melal~ostoma mellirzum is an important The abdominal pattern is different in both sexes pollinator of anemophilous plants (STELLEMAN& but the yellow markings on tergites 3 and 4 cover MEEUSE1976) and sometimes preying on serious parts of lateral margins. The male terminalia are aphid pests (MALINOWSKA1979). remarkably large. FLIGHTPERIOD: March to November in the South DISTRIBUTIONAND BIOLOGY:This species is of Europe. present in the Palaearctic Region, including all ACTUALSTATUS: Since 1930 no more recent the Macaronesian islands. Eupeodes corollae is records exist of this species from the Azores. It is also present in Africa and . This hoverfly necessary to take more samples to confirm the lives in a wide range of ecosystems, mainly in current situation of this species. open areas but it is also abundant in many LOCALITIES:SBo Miguel: Fu, VIII-IX-SG agroecosystems (e.g. arable fields, gardens). The larvae are found feeding on a wide range of ground layer aphids. The high mobility of this az~ricollis(Meigen, 1822) species and its ability to prey on several species of aphid pests, have been tested for use in is a narrow-bodied hoverfly biological control. Eupeodes corollae is highly with a typical pattern on the third and fourth migratory and, for this reason, can be very abdominal segments. On these tergites yellow numerous some years (STUBBS & FALK1993). bands exist, deeply cut at the middle, often giving FLIGHT PERIOD: May to September, but this range separate spots. Nevertheless, there is a wide range can be longer in the southern Europe. of variation in this pattern for example the variety ACTUALSTATUS: Cited from all the islands except maculicornis is a common dark form. Graciosa but without doubt should also be present DISTRIBUTIONAND BIOLOGY:The main area of in this island. distribution of Meliscaeva nuricollis is the West LOCALITIES:Corvo: VN, VI 1938-FR. Faial: H, Palearctic Region. Moreover, it has been cited V+VII 1938-FR; P, V+VII 1967-GM. Flores: Ae, from all the Macaronesian islands. Preferred IX 1979-GO; FG, IX 1979-GO; PDe, IX 1979- environments of this species are forests and GO; RB, VI 1938-FR; RFz, VI 1938-FR; SCF, IX conifer plantations but it is also abundant in some anthropogenic habitats (SPEIGHT& LUCAS1992). Females of albi~nan~ishave grey This species is also highly migratory and the spots on the tergite but in the male they are larvae prey on several species of aphids and larvae usually a dull bronze. of other (GOELDLINDE TIEFENAU1974). DISTRIBUTION AND BIOLOGY: Present in FLIGHT PERIOD: March to September but Palaearctic and Nearctic Regions, but in hibernating adults are able to fly during autumn Macaronesia only in the Azores. This species is and winter, in southern Europe. found in a wide range of biotopes, especially ACTUALSTATUS: This species has been only cited abundant in association with man-modified by FREY (1945) during the summer of 1938. environments (SPEIGHT& LUCAS1992). AUBERT However, this highly migratory species is probably et al. (1976) cited this species as migratory. present in all the islands of the archipelago. FLIGHTPERIOD: March to November in southern LOCALITIES:Flores: RCz, VI 1938-FR. Pico: Md, Europe. VII 1938-FR; S, VII 1938-FR. Siio Jorge: LCh, ACTUALSTATUS: Cited only from Flores and Siio VI 1938-FR; RS, VI 1938-FR. Siio Miguel: Fu, Miguel but probably also present in the central VII 1938-FR; RQ, VII 1938-FR. Terceira: An, islands. VI-VII 1938-FR. LOCALITIES:Flores: RdB, IX 1979-GO. Siio Miguel: PDI, VIII-IX 1930-SG. Myatlzropaflorea (Linnaeus, 1758) Platyclzeirus rosarum (Fabricius, 1787) This syrphid can be easily recognised by the pattern of the thoracic dorsum which is partially This species has a typical pattern with only two divided by a pair of yellow pale bars. yellow pale spots at the front margin of tergite 3 DISTRIBUTIONAND BIOLOGY:This Palaearctic of the black abdomen. species is present in the Canaries and Azores. On DISTRTBUTIONAND BIOLOGY:Holarctic species Madeira occurs the endemic Myatlzropn but in Macaronesia is only present in the Azores. mallotiforrnis Frey, 1939. Adults are abundant in The preferred habitats are , streams or forests and the larvae are associated with wet river banks. The larva is undescribed but the decaying vegetation in rot-holes and similar puparia have been found in flood debris habitats (ROTHERAY1993). (ROTHERAY& GILBERT1989). FLIGHTPERIOD: May to October. FLIGHTPERIOD: May to September. ACTUALSTATUS: The subspecies cited by FREY ACTUALSTATUS: Only cited in 1930 on Terceira. (1945) and GOMES(1980) are considered in the More records would be necessary to confirm the Palaearctic Catalogue of PECK (1988) as presence of this species in the Azores. synonyms of M. florea. This species has not been LOCALITIES:Terceira: MB, VIII-IX 1930-SG cited from all the islands but is probably present on those that allow the development of its Sphaerophoria nigra Frey, 1945 biological cycle. LOCALITIES: Flores: RFz, VI 1938-FR; SCF, IX 1938-GO. Santa Maria: AP, IX 1979-GO; Pa, IX Endemic species from the Azores without the 1979-GO; VP, IX 1979-GO. Siio Jorge: RF, VI typical yellow stripe on the sides of the thoracic 1938-FR. SBo Miguel: Fu: VIII-IX 1930-SG, V dorsum. All the body is black except the yellow 1938-FR; LCa, 24-IX-lg95,ld 3 9 9 -OD; LFu, scutellum. VOCKEROTH (1971) drew the surstylus VII 1938-FR. Terceira: MB, V l938-.FR. of male genitalia. DISTRIBUTION AND BIOLOGY:Only present in the Azores. There are no data about the biology of Platycheirus albimanus (Fabricius, 1781) this species but it probably preys on species of aphids. The males of the genus Platyclzeirus often have FLIGHTPERIOD: Sphaerophoria nigra has been the front tibiae and tarsi conspicuously flattened. cited from June to September. ACTUALSTATUS: Cited from six islands but LOCALITIES:SHo Miguel: without locality, VII- probably exists on more. It is necessary to know VIII 1990-CZ. the ecology of this species in order to protect the habitats where it lives. Sphaerophoria scripta (Linnaeus, 1758) LOCALITIES:Faial: C1, VII 1938-FR; RCa, VII 1938-FR. Flores: M, VI 1938-FR; MF, IX 1979- This abundant aphidophagous species may be GO; RdB, IX 1979-GO; Va, VI 1938-FR; Pico: S, easily recognized in the field by the long VII 1938-FR. SHo Jorge: RS, VI 1938-FR. SHo abdomen of the males. Miguel: Car, 24-IX-1995, 1 0 -OD; LCa, 24-IX- DISTRBUTIONAm BIOLOGY: Sphaerophoria 1995, 2 0 0 -OD; LF, VIII 1938-FR; PV, VII scripta is present in the Holarctic region and 1938-FR. Terceira: B, VII 1938-FR. some parts of Asia. It has been cited from all the Macaronesian islands. This species can be present (Meigen, 1822) in a wide range of habitats but is more abundant in open ground and grassland (including Considerable care is needed using old records and agroecosystems). Together with Episyrplzus the specimens need re-examination observing balteatus and Eupeodes corollas, this species has genitalia characteristics. Identification must be been used in the biological control of aphids based on the male genitalia, the toothed lobe (LASKA1984). FLIGHTPERIOD: April to November in South being very broad (STUBBS& FALK1993). Europe. This species is polyvoltine and highly DISTRIBUTIONAND BIOLOGY:Palaearctic species but in Macaronesia only cited from the Azores. migratory (AUBERTet al. 1976) with marked The larva is undescribed. dispersal during the summer months (SPEIGHT& FLIGHTPERIOD: May to August. LUCAS1992). ACTUALSTATUS: Since S~GUY(1936) no more ACTUALSTATUS: Probably the most common data exist about this species in the Azores. This species of hoveffly in the Azores archipelago. It has been cited from all the islands. author cites the species as Sphaerophoria LOCALITIES:Corvo: Ca, VI 1938-FR; VC, IX merzthastri (L.) var philanthus Meigen. 1979-GO. Faial: C1, VIII 1938-FR; H, V+VIII LOCALITIES:S5o Miguel: Fu, VIII-IX 1930-SG. 1938-FR; RFl, VII 1938-FR. Flores: Ae, IX 1979- GO; A1 IX 1979-GO; Ce, IX 1979-GO; FG, IX (Wiedemann, 1830) 1979-GO; FSC, IX 1979-GO; MF, IX 1979-GO; PDe, IX 1979-GO; PR, IX 1979-GO; RB, VI The short body, broadened towards the apex is 1938-FR; RFz, VI 1938-FR; RdB, IX 1979-GO; the most distinctive character of this species. SCz, VII 1938-FR; SCF, IX 1979-GO;Va, VI DISTRTBUTIONAND BIOLOGY:Present in all the 1938-FR. Graciosa: Cd, VII 1938-FR. Pico: LC, Palaearctic Region and very common in the VII 1938-FR; Md, VII 1938-FR; S, VII 1938-FR. Mediterranean region (DIRICKX 1994). In SHo Jorge: C, VI 1938-FR; IT, VI 1938-FR; RS, Macaronesia Sphaerophoria rueppellii has been VI 1938-FR. Santa Maria: G, IX 1979-GO; cited from the Canaries and the Azores. Several without locality, V 1967-GO. SBo Miguel: AA, authors note that this species is abundant in VII 1978-GM; Ba, 27-IX-1995, 1d 1 0 -OD; Car, several crops and probably plays a great role in 24-IX-1995, 10-OD; Fu, VIII-IX 1930-SG; GP, the control of some species of aphids (HUBICKA VI 1979-GM; LF, VIII 1938-FR; PCr, 24-IX- & ZUKOWSKA1969; LASKA1984). 1995,288 29 ?-OD; PDl: VIII-IX 1930-SG; V FLIGHT PERIOD: April to November in South 1938-FR; VI-VII+IX 1979-GM; X 1979-GO; RG: Europe. V 1938-FR; 26-IX-1995, 18-OD; SR, V+VII ACTUAL STATUS: Cited recently from SHo Miguel 1938-FR; SAP, VI 1979-GM. Terceira: Ac, VII (CRUZ DE BOELPAEPE1991), it is probably a 1938-FR; An, V 1938-FR; B, V 1938-FR; Fn, VI recent introduction. I~-FR;MB: v m - ~1930-SG; x v WB-FR. Syrittapipiens (Linnaeus, 1758) conifer plantations or gardens. This hoverfly is often abundant at aphid colonies with a wide This species has a narrow body with a pair of range of ground layer and arboreal aphids. orange spots on tergites 2 and 3. The hind femora Overwinter as larvae. are very strong. FLIGHTPERIOD: March to November in South DISTRIBUTIONAND BIOLOGY: This hoverfly is Europe. present in all regions of the world except ACTUAL STATUS: Colonization is probably . It has been cited from all the recent. Macaronesian islands. Usually, this species is LOCALITIES:S5o Miguel: without locality, VII- abundant, especially in wetlands, along the border VIII 1990-CZ. of fresh-water and in anthropogenic environments. Larva found in various kinds of azorensis Frey, 1945 wet decaying matter. FLIGHTPERIOD: March to November. Xanthandrus azorensis and Sphaerophoria nigra ACTUALSTATUS: Cited from six but probably are endemic to the Azores archipelago. Both are abundant on all islands. black species. LOCALITIES:Faial: H, VII 1938-FR; RCa, VII DISTRIBUTIONAND BIOLOGY:Only present in the 1938-FR. Flores: Ce, IX 1979-GO; FG, IX 1979- Azores. There are no data about the biology but it GO; MF, IX 1979-GO; RCz, VI 1938-FR; RFz, probably preys on aphids or larvae of Lepidoptera VI 1938-FR; RdB, IX 1979-GO; SCZ, VII 1938- as do continental species of the genus FR; SCF, IX 1979-GO; Va. VI 1938-FR. Santa Xanthandrus. Maria: AP, IX 1979-GO; F, IX 1979-GO; G: IX FLIGHTPERIOD: June to September. 1976-GO; IX 1979-GO; ME, IX 1979-GO; PSP, ACTUALSTATUS: There have been no records of IX 1979-GO; Pa, IX 1979-GO; VP, IX 1979-GO. this species since 1938 but we collected several S5o Jorge: C, VI 1938-FR; RF, VI 1938-FR. S5o individuals (males and females) in peat-bog areas. Miguel: Ba, 27-IX-1995, Id 1 ? -OD; Car, 24- LOCALITIES:Faial: H, VIII 1938-FR; RE, VII IX-1995, 28d 4 ? ?-OD; Fu: VIII-IX 1930-SG; 1938-FR; RFI, VII 1938-FR. Pico: LC, W 1938- V+VII 1938-FR; Gr, 26-IX-1995,2d d-OD; LCa, FR; without locality, VII 1938-FR; S, VII 1938- 24-IX-1995, 5 9 0 -OD; LF: VIII 1938-FR; IX-X FR. S5o Jorge: RF, VI 1938-FR; RS, VI 1938-FR. 1979-GO; LFu, VII 1938-FR; PCr, 24-IX-1995, Siio Miguel: Ba, 27-IX-1995, 2a d 1 ?-OD; Fu, Id 1 ?-OD; PDl, V 1938-FR; RG, 26-IX-1995, V+VII-VIII 1938-FR; LCa, 24-IX-1995, 3 ? 9 - Id-OD; SR, V+VIII 1938-FR; SC: VIII-IX 1930- OD; SC, vm-IX1930-SG. SG; V 1938-FR. Terceira: Ac, VI 1938-FR; Ag, VI 1938-FR. (Harris, 1776)

Syrphus ribesii (Linnaeus, 1758) The abdomen of this fly has a distinctive pattern with a pair of round spots on the second species have bands on tergites 3 and 4. tergite. Both sexes of Syrphus ribesii present basal cells DISTRIBUTIONAND BIOLOGY:Present in all the of the wing completely covered by microtrichia, Palaearctic region but in the Macaronesia it is but there are no hairs on the eyes. only present in the Azores. Xanthandrus comtus DISTRIBUTIONAND BIOLOGY:Present in the occurs in meadows and woodland borders Holarctic region and recently in the Macaronesian (STUBBS& FALK1993). It is a migratory species islands: Canaries (BAEZ1977a), Madeira (GOMES (AUBERTet al. 1976), and predator of several & BAEZ 1990), Azores (CRUZ DE BOELPAEPE tortricid and other caterpillars (LYON 1968; 1991). Probably all these records are new ROTHERAY& BLAND1993). introductions. Syrphus ribesii is specially FLIGHTPERIOD: March to November but probably abundant in anthropogenic habitats such as crops, all year round in southern Europe. ACTUAL STATUS:Probably a recent colonization. 2a Third antennal segment black or brown Locally abundant in ,550 Miguel and might be Eumerus strigatus present on other big islands. 2b Third antenna1 segment red or reddish LOCALITIES: Siio Miguel: Ba, 27-IX-1995, 1 d- Eumerus amoerzus OD; LC& 24-IX-1995, 38$-OD; PCr, 24-IX- 3, Wing with R 4+5 sha]low]y dipped or more 1995,19-OD; PDI, X 1979-GO. nearly straight (Fig. 1-IIb) 4 3b Wing with R 4+5 strongly looped (Fig. I-IIIa) Xylota segnis (Linnaeus, 1758) 8 4a Wing with inner cross vein before middle of The abdomen of this species has parallel sides discal cell (Fig. 1-Ilc) 5 and a reddish orange band uniformly coloured at 4b Wing with inner cross vein at or beyond the hind edge of the second tergite. middle of discal cell (Fig. 1-IIIb) 6 DISTRIBUTIONAND BIOLOGY: Xylota segnis is 5a Tergite 2 with two small yellow markings. present in most parts of the Palaearctic region and Hind femur noticeably swollen and arched eastern parts of N. America. Moreover it has been pipiens cited from all the Macaronesian archipelagos. 5b Tergite 2 largely orange. Hind femur slender This is an anthropogenic species living in forests Xylota segnis including gardens and other agroecosystems. The 6a Face entirely yellow or at least yellow at the larvae feed on decaying sap under bark and sides 11 various types of rotting vegetable material e.g. 6b Face entirely black 7 rotting potatoes. 7a Abdomen very thin (at narrowest, no wider FLIGHT PERIOD: March to November in southern than scutellum) Europe. According to AUBERT et al. (1976), Bacclza elor~gata Xylota segnis is more of a migrant than other 7b Abdomen more compact 19 species of the genus. 8a Wing with the two anterior radial veins (R1 ACTUAL STATUS: Common species on SZo and R2+3) meeting to form a short stalk before Miguel and probably present on all islands. reaching the wing margin (Fig. 1-IIIc) 9 LOCALITIES: Faial: RE, VII 1938-FR. S5o 8b Wing with these veins only just meeting at the Miguel: Fu: X 1979-GO; VIII-IX 1930-SG; wing margin or widely separated (Fig. 1-IId) V+VII 1938-FR; Gr, X 1979-GO; 29-IX-1995, florea 28d 1 ?-OD; PDI, X 1979-GO. Terceira: Ac, VI 9a Scutellum black; eyes with spotted pattern 1938-FR; Ag, VI 1938-FR. Eristalitzus aeneus 9b Scutellum not black; eyes never with a spotted KEY TO SYRPHID SPECIES CITED FROM THE pattern 10 AZORES 10a Face with black central stripe very wide, maximum one third width This key should be used only to identify Eristalis terznx syrphids from the Azores islands. It includes all lob Face entirely pale dusted, absolutely no trace the species cited from the literature till now. For of a ccntral black stripe descriptions and keys of European hoverfly Eristalis arbustorum species, GIL-COLLADO(1930), SACK (1932), llaThoracic pleura with clear yellow markings SBGUY(1961), VAN DER GOOT (1981), STUBBS 12 & FALK (1993) and TORP (1994), should be llb Thoracic pleura entirely dark or pale areas consulted. obscured by dust 13 la Upper outer cross vein re-entrant (Fig. 1-Ia) 12a Antennae long and prominent 2 Chrysotoxum intertnediunz lb Upper outer cross vein not re-entrant (Fig. 1- 12b Antennae otherwise. Small narrow species IIa) 3 17 17a Thorax with yellow side stripe interrupted above wing base Sphaerophoria rueppellii 17b Thorax with continuous yellow side stripe 18 18a Abdomen extends well beyond wing tips. Genital lobes from side view very broad Sphaerophoria scripta 18b Abdomen extends to about wing tips. Genitalia seen from beneath elongate with lobes longer than broad Sphaerophoria philanthus 19a Large oval bodied species 20 19b Smaller species with elliptical or parallel sided abdomen 21 20a Second abdominal segment with a pair of dorsal yellowish spots Xanthandrus comtus 20b Second abdominal segment without spots Xanthandrus azorensis 21a Abdomen entirely black Sphaerophoria nigra 21b Abdomen with spots or bands 22 22a Abdomen black with distinctive band or pair of yellowish spots only on tergite 3 Platycheirus rosarum Fig. 1. Syrphid wing diagrams showing term (lettering) 22b Abdomen with a different pattern 23 used in the key. 23a Males (eyes meet on top of head) 24 23b Females (eyes separated on top of head) 25 24a Front tibiae broadened at apex and tarsi 13a Long yellow hairs on the upper surface of the partly flattened. Tergites black with silver spots squama, especially on posteromedian portion Platycheirus albimanus Syrphus nbesii 24b Front tibiae and tarsi cylindrical; abdomen 13b Upper surface of the squarnae with only strongly widening posteriorly. Tergites microscopic pile (If doubtful, continue here) 14 extensively yellowish. 14a Tergites 3 and 4 with double black bands, Melanostoma mellinurn sometimes reduced 25a Tergites with silver spots or bands Episyrphus balteatcls Platycheirus albimanus 14b Markings otherwise 15 25b Tergites 3 and 4 with roughly triangular spots 15a Line of hairs on the side margins of tergites pointing outwards towards sides. 3-5 all black Melanostoma mellinurn Eupeodes corollae 15b Hairs on the side margins of tergites 3-5 partly pale 16 DISCUSSION 16a Narrow species. Tergites 3 and 4 with wedge shaped spots There have been 23 species of hoverflies cited Meliscaeva auricollis from the Azores archipelago. However after the 16b Broader species. Tergites 3 and 4 with bands L. Chopard and A. MBquignon expedition in always sweeping forwards at lateral margins. 1930, no new data of the following four species Hind femora yellow for at least apical third has been produced: Baccha elongata, Syrphus ribesii Chrysotoxum intermedium, Platycheirus rosarum and Sphaerophoria philanthus. The presence of Macaronesian islands. In Azores, Madeira and Eumerus strigatus should also be confirmed (see Cape Verde exist only one species of this genus, Eumerus amoenus paragraph). Moreover, none of but there are 9 cited from the Canaries (BAEZ these species has been cited on the other 1982a), 7 endemic and one more living in the Macaronesian islands. On the other hand, Canaries and Madeira (Table 1). although Melanostoma mellinum has not been Analysing the biogeographic elements, we cited since 1930, we consider this species present observe that the percentage of syrphid endemic in the Azores, as it is a common syrphid in species in Azores is 9 % (Fig. 4). This rate is Madeira (GOMES& Bbz 1990) and other species similar to the total of endemic species of insects of this genus are known in the in the archipelago (BIVARDE SOUSA1985). This (BAEZ1977a). percentage is similar in Cape Verde (8.3 %), in Though more exhaustive sampling would be Madeira it is about 15 %. The highest is in the necessary on some of the Azores islands (i.e.: Canary Islands with 36 % of syrphid endemic Graciosa and Corvo), probably the total number species. In accordance with this, the Canaries is of hoverfly species living in the archipelago is not greater. According to the theory of island biogeography (MACARTHUR& WILSON 1967) there would be a correlation between area and number of species. We can show this relation plotting the log of island-areas against log of species number, on a double logarithmic scale. In the case of syrphids, we get low values of regression between both factors (r2 = 0.520). However we can improve these results (r" 0.718) by removing the former five doubtful species and consider the presence of 4 common synanthropic or highly migratory species, and with wide geographical distribution on all islands (Eristalis tenax, Eristalinus aeneus, Episyrphus balteatus and 1 10 Log (Area) Eupeodes corollae) (Fig. 2). Fig.- 2. Regression- between Area and Number of Related to the larval biology of syrphids syrphid species present in Azores Archipelago. present in the Macaronesian archipelagos, we can observe that the rate of the three main lines of feeding ecology (predacious, 70 1 Azores saprophagous and phytophagous) differs (Fig. Madeira 3). The percentage of predacious and Cape Verde saprophagous species is similar in continental Canaries Mediterranean ecosystems (IsIDRO 1995; PEREZ-BAfi6~1995). In relation to this, the syrphids with more capacity to fly including highly migratory species, belong to predacious and saprophagous groups (TORP 1994). However, the proportion of phytophagous larvae is much too low, in all the Macaronesian islands except Canaries Predacious Saprophagous Phytophagous (Fig. 3) probably because this archipelago is closer to mainland. Eumerus is the only genus Fig. 3. Larval feeding habits of the hoverflies present in of phytophagous syrphids cited from the the Macaronesian region. also the archipelago with more endemic plants (Fig. 5). With the UPGMA analysis (group (BOLOS1996). The Palaearctic influence is more average clustering) using the Serensen Index important in the Azores and Madeira than in the (S~RENSEN1948), we found that Madeira and the Canaries. However, in Cape Verde the influence Canaries are more related to the Azores than to of Afrotropical elements is the highest (BAEZ Cape Verde. According to these data, there are 1982b). The Nearctic element has not been cited only 3 species of hoverflies present in all four in the syrphid fauna from the Macaronesia and archipelagos: Eristalis tenax (Cosmopolitan), the presence of Holarctic species is only Eristalinus aeneus (Sub-cosmopolitan) and important in the Azores and Madeira (CLAUSSEN Eupeodes corollae (Palaearctic+Palaeotropical & BARKEMEYER1987). We can explain these species). On the other hand, six species results by the long distance to the continent from (Episyrphus balteatus, Meliscaeva auricollis, the Azores and their geographical position in the Sphaerophoria scripta, , Syrphus north of the Macaronesia, far from Afrotropical ribesii and Xylota segnis) are present in the influence. Azores, Canaries and Madeira. However, only We can compare the syrphid species two species Ischiodon aegyptius and Scneva composition in the archipelagos of Macaronesia albomaculata are present in Cape Verde, the Table 1

Macaronesian hoverfly species AZORES MADEIRA CANARIES CAPE VERDE

Bacha elorzgata Episyrphus balteatus Chainaesyrphus. . nigricornis -. nasuta Chryxotox~rmintermedium Eristalinus aeneus Chrvxotoxum triarcuatum Eristalinus aeneus Episyrph~rsbalteatus Eristalis tenax Episyrphus balteatus Eristalinus aeizeus Eumerus purpureus Eristalinus aeneus Eristalis tenax Eristalis arbostorum Eupeodes corollae Eumerus erythrocer~is Eristalis teizax Eupeodes luniger Eristalis tenax Eupeodes corollae Euinerus ainoenus Ischiodon aegyptius Eumerus canarieizsis Ischiodon aegypti~rs Eupeodes corollae Melanostoma babyssa Eumerus dubius Ischiodon feae Melanostoma mellinum Melanostoma inellinurn Eumerus latitarsis Paragus borboizicus Meliscaeva auricollis Meliscaeva auricollis Eumerus nivariae Paragus pusillus Myiatropa florea Milesia crabroniforinis Eumerus pulchellus Scaeva albomaculata Platycheirus albimarzus Myiatropa mallotiformis Eumerus purpurariae Syritta flaviventris Platycheirus rosarum Neoascia podagrica Ecrmerus purpureus Sphaerophoria ~zigra Paragus coadunatus Eumerus saiztosabreui Sphaerophoria philantkus Scaeva albomaculata E~rmerustenniizalis Sphaerophoria rueppellii Scaeva pyrastri Eupeodes corollae Sphaerophoria scripta Scaeva selenitica Eupeodes interrumpens Syritta pipieizs Sphaerophoria scripta Heringia adpropinquans Syrphus ribesii Syritta pipiens lschiodon aegyptius Xantlzandrus azorensis Syrphus ribesii Melanostoma iizcompletum Xaiztlzandrus cointus Syrphus towus Meliscaeva auricollis Xylota segnis Syrphus vitripeiznis Myiatropa florea Xaizthandrus parhyalirzatus Paragus coadunatus Xylota segnis Paragus tibialis Scaeva alboinaculata Scaeva pyrastri Sphaerophoria rueppellii Sphaerophoria scrip ta Syritta pipiens Syrphus ribesii Xvlota semis Endemic Mediterranean Palearctic Palearctic+Oriental/ PhearctiwOrientd+Australian Palaeotmpical+Palearctid Afrotropical+Palearctic Hotoartic EIoloartic+Oriental CosmopolitanlSubcosmopoIitan

Fig. 4. Biogeographical elements in the Azores archipelago referring to syrphid fauna.

Canaries and Madeira (Table 1). The absence of genus Scaeva in the Azores is surprising because these hoverflies are strong flyers and have been cited from all the other Macaronesian islands. The terrestrial fauna and flora of the northern Macaronesian islands are more related to the west European than to African (BALLETTO et al. 1990). The Azores archipelago never had "land-bridges" with the European or the African mainland. Flies (Diptera) are the most abundant insects in the Azores archipelago with a percentage of species near to 30% (BNAR DE SOUSA1985) and the order has more endemic species than any other, 40 in 420, i.e. about 10% (Bivar de Sousa pers. commn). Our data on Syrphidae Cab Az Mad Cal show an endemism of about 9% (2 of 23), the endemic species being Sphaerophoria nigra and Xanthandrus azorensis. However, more faunistic studies and analysis of the ecology Fig. 5. UPGMA analysis (group average clustering) of of the most representative species of these species of hoverflies in Macaronesian region. fascinating islands are needed.

ACKNOWLEDGMENTS Manchester Metropolitan University) for allowing us to study specimens from Macaronesian islands. We wish to thank Dr. Marcos BBez (University of This study was supported in part by a grant from La Laguna, Tenerife) and Dr. Matthew Sullivan the Research Project GV-1175/93 from (Department of Biological Sciences, The Generalitatvalenciana. REFERENCES dans plusieures biotopes de 1'Fle de SBo Miguel, Aqores. Arquipe'lago. Life and Earth Sciences 9: 11-23. ANKERSMIT.G.W., N.J. DUKAM,N.J. KEUNING,H. DIAS,E. 1994. Patrimdnio Vegetal dos A~ores.Centres MERTENS,A. SINS & H.M. TACOMA1986. of Plant Diversity: A guide and strategy for their Episyrphus balteatus as a predator of the aphid conservation. IUCN Plant Conservation Office & Sitobion avenue on winter wheat. Entomologia WWF International (eds.), Angra do Heroismo 1- Experimentalis et Applicata 42: 271 -277. 17 PP. AUBERT,J., J.J. AUBERT& P. GOELDLINDE TIEFENAU DIRICKX,H.G. 1994. Atlas des Dipttres syrphides de la 1976. 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