Spilomyia Species (Diptera: Syrphidae) in Dutch Collections, with Notes on Their European Distribution
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Spilomyia species (Diptera: Syrphidae) in Dutch collections, with notes on their European distribution Aat Barendregt, Jeroen van Steenis & Wouter van Steenis BARENDREGT A J VAN STEENIS & W. VAN STEENIS, 2000. SPILOMYIA SPECIES (DIPTERA: SYRPHI¬ DAE) IN DUTCH COLLECTIONS, WITH NOTES ON THEIR EUROPEAN DISTRIBUTION. - ENT. BER., AMST. 60 (3): 41-45. Abstract: The identity of the specimens of the genus Spilomyia in Dutch collections was checked. All published obser¬ vations of S. saltuum from The Netherlands appear to refer to S. manicata. This species was never reported for the Dutc fauna before However, S. saltuum remains on the Dutch check list with two hitherto unpublished specimens. An upda¬ ted key to the four species known from Central and Western Europe is added. Specimens in Dutch collections show that S. dieitata has a strictly Mediterranean distribution and S. diophthalma has its optimum m the boreo-alpine region. Spilomyia manicata is widely distributed in Europe, whereas S. saltuum has its main distribution area in Sout ern Europe. Keywords: Spilomyia, mis-identification, key, distribution, ecology. A. Barendregt, Koninginnelaan 9, 3781 GK Voorthuizen, The Netherlands. J. van Steenis, Department of Zoology, Uppsala University, Villavägen 9, 75236 Uppsala, Sweden. W. van Steenis, Androsdreef 52, 3562 XB Utrecht, The Netherlands. Lucas (Rotterdam), W. Renema (Leiden), M. Introduction van Veen (Zeist), J. Smit (Velp), J. van Flies of the genus Spilomyia Meigen are rare Steenis (Uppsala, Sweden) and W. van Steenis throughout Europe (Speight, 1988) and occur (Utrecht). most frequently in the Mediterranean region. The larvae of Spilomyia inhabit damp rot¬ Also from The Netherlands there are only a ten timber in hollow trees and decaying heart- few records available (Barendregt, 1994) and wood of deciduous trees (Stackelberg, 1958; Spilomyia saltuum (Fabricius) is the only spe¬ Rotheray, 1993). Adult Spilomyia are large cies reported from our country. The species is hoverflies (12-17 mm) showing a striking re¬ already mentioned in Van der Wulp & De semblance with social wasps. Observations in Meijere (1898). Since it was the only species behaviour indicate that they also imitate known from The Netherlands, Belgium and wasps: the front legs are used to wave and thus Denmark (Van der Goot, 1981; Verlinden, resemble long antennae. Specimens of S. 1991; Torp, 1994) all Spilomyia specimens diophthalma (Linnaeus) were observed in were initially identified as S. saltuum. Sweden vibrating their wings while crawling Given attention by a remark of Theo Zee- about on flowers, imitating the folded wings gers about the presence of Spilomyia manica¬ of vespids. When captured in the net they buzz ta Rondani in Poland and the possible disper¬ loudly and crawl about, stopping very fre¬ sion in this species, we decided to check the quently to press down the tip of the abdomen identity of all specimens of this genus in the as though they would sting (Curran, 1951). It Dutch collections. A number of 117 speci¬ is supposed that the adults fly high in the tree mens were studied from the following collec¬ canopy and come down only to drink or teed, tions: Naturalis (Leiden), Instituut voor especially on late flowering umbellifers like Taxonomische Zoölogie (Amsterdam), Sectie Cicuta virosa L., Pastinaca sativa L„ Angeli¬ Entomologie Landbouwuniversiteit (Wage¬ ca sylvestris L. and Heracleum sphondylium ningen) and the private collections of J. A. W. L. (Speight, 1988; Nielsen, 1990). However, 42 Ent. Ber., Amst. 60 (2000) other observations do not support this. In on Stackleberg’s key, but in with some addi¬ Sweden we observed males of S. diophthalma tional characters are used. flying rapidly from flower to flower, sear¬ ching for females, and sometimes even cha¬ Key to the Central and Western European sing social wasps. This behaviour has also species of Spilomyia been observed in North America (Waldbauer & Ghent, 1984). Moreover, the last author ob¬ 1 Pleura black with three yellow spots (fig. served a male S. saltuum in the Dordogne 1). Posterior margin of the scutellum oran¬ (France) in a Populus-plantation flying from ge red. Hairs on mesonotum, scutellum, tree to tree, each time resting for a moment on and pleura long and erect. Legs yellow- a trunk or on Populus-leaves near the trunk brown to red. Abdomen predominantly about one metre above surface. black, with narrow yellow bands (fig. 2) ... S. diophthalma - Pleura black with more than three yellow Identification spots (fig. 3, 5 and 7). Posterior margin of The genus Spilomyia can be distinguished the scutellum yellow. Hairs on mesonotum, from the related genera Milesia Latreille and scutellum, and pleura ranging from medi¬ Temnostoma Lepeletier & Serville by the fol¬ um lenght to short and adpressed. Legs yel¬ lowing combination of characteristics: wing low-brown and black. 2 cel I open (also in some Milesia, in all 2 Mesonotum with fairly long, erect hairs. Temnostoma), the strongly oblique vein r-m Pleura with five yellow spots (fig. 3). Front (also in some Milesia), the apico-ventral pro¬ tarsus totally black, front tibia black over lateral spur on the hind femur (also in some more than its apical half. Abdomen with the Milesia) and an obvious brown/yellow colour anterior yellow band on tergites II and III pattern on the eyes in living specimens not interrupted, or at most very small inter¬ (Hippa, 1990). The scutum has a characteristic rupted in the middle (fig. 4) ... S. manicata V-shaped drawing in front of the scutellum. - Mesonotum with short adpressed hairs. During the last century there has been con¬ Pleura with four or five yellow spots (fig. 5 fusion about the identity of European Spilo¬ and 7). Front tarsus black, at least the last myia species. Sack (1910) treats four species tarsomere yellow, front tibia black over less presently known from Central and Western than its apical half. Abdomen with the ante¬ Europe: Spilomyia saltuum, S. manicata, S. rior yellow band on tergites II and III most¬ diophthalma and S. digitata Rondani. Kuntze ly interrupted (fig. 6 and 8) . 3 (1913) only refers to S. saltuum in describing 3 Pleura with four yellow spots (fig. 5). Front the new species S. integra Kuntze. In Sack tarsus black, the fifth tarsomere yellow. (1930) only S. diophthalma and S. saltuum are Abdomen with the anterior yellow band on keyed out. In his next key (Sack, 1932) S. in¬ tergites II and III widely interrupted, domi¬ tegra is included, but S. digitata is synonymi- nating colour yellow (fig. 6) .... S. digitata zed with S. manicata. Moreover, Sack (1932) - Pleura with five yellow spots (fig. 7). Front does not use the obvious characteristic erect tarsus black, the fourth and fifth tarsomeres hairs in S. manicata as a key characteristic. yellow, sometimes whole tarsus yellow. Stackelberg ( 1958) considers S. digitata and S. Abdomen with the anterior yellow band on manicata as separate species, and S. integra as tergites II and III less widely interrupted, a synonym of S. manicata. A number of aut¬ dominating colour black (fig. 8) . hors (Séguy, 1961; Bankowska, 1963; Van der . S. saltuum Goot, 1981) produced keys based on the one presented by Stackelberg (1958). Below we Spilomyia specimens in Dutch collections present a key to the four Central and Western European species of Spilomyia, which is based Using the above key, we identified all Euro- 43 Ent. Ber., Amst. 60 (2000) Fig. 1-8. Thorax and abdomen of male Spilomyia species. 1-2, 5. diophthalma (Switzerland); 3-4, S. mamcata (France); 5-6, S. digitata (Italy); 7-8, S. saltuum (Greece). pean Spilomyia's present in the Dutch collec¬ presented by 22 specimens. All specimens ori¬ tions. All specimens were collected in summer ginate from locations in Central and Northern and the beginning of autumn (mostly July and Europe. Most specimens in the collections are August); differentiation in flight period be¬ from the Swiss, Italian and Austrian Alps, tween the species cannot be indicated. In con¬ from locations with an altitude of above 1000 trast, the distribution of the represented speci¬ m, where other Spilomyia species seldom are mens of the four species is quite different. collected. Next to that, specimens from Nor¬ Spilomyia digitata - This species is repre¬ way, Sweden and Finland are well represen¬ sented by 26 specimens, all originating from ted. We have seen two old specimens from Southern Europe, with specimens from non-boreo-alpine areas in Germany. Speci¬ Greece, Macedonia, Italy (including Sicily), mens from non-mountainous locations in the extreme South of France (including Cor¬ Eastern Europe (Poland and Russia) are in line sica) and Spain. Only some very old speci¬ with this distribution. Bankowska (1959) adds mens from Eastern Austria (lower parts) and more observations from Poland. Bulgaria is Central Germany are not from the Mediterra¬ mentioned in Peck (1988). nean region. It is also recorded from Switzer¬ Spilomyia manicata - This species is repre¬ land (Maibach et al„ 1992), Portugal (Gomes, sented with 31 specimens. All specimens from 1980) and Romania (Peck, 1988). The Netherlands published as S. saltuum tur¬ Spilomyia diophthalma - This species is re¬ ned out to be S. manicata, a species not repor- 44 Ent. Ber., Amst. 60 (2000) ted for the Dutch fauna before. Spilomyia ma- Discussion nicata is known from Driebergen (1 9, circa 1890; Van der Wulp & De Meijere, 1898), We should be careful when accepting the Huizerheide-Gooi (1 9, 24.viii.1915; De identification of other authors without check¬ Meijere, 1916) and Helmond (1 9, 21.viii. ing the specimens with the latest opinions in 1954; Van der Zanden, 1959). A specimen taxonomy. We ourselves are an example since from Echt, De Doort (1 9, between 1950 and after a century it turned out that the four pu¬ 1960; Geurts, 1961) has been lost.