7.b. Frons, immediately posterior to the 758. lunulae, shiny black; sternites frequently black marked laterally and medially. Male: femur 3 black for 2/3 of its length; female: black area on frons with a pos- tero-median triangular extension point- ing towards the occiput, then entirely covered with silver-grey dusting back almost as far as the ocellar triangle, ocel- lar triangle and posterior 1/4 of the frons shiny black; femur 3 yellow; lateral mar- 759. gins of tergites yellow only at the ends of the bands (rarely paired spots); antennae black above, orange below; front tarsus darkened. 10-12 mm. Europe, in Asia into Japan, Nearctic highly migratory › Syrphus ribesii (Linnaeus) 8.a. Lateral margins of tergites continuous- ly yellow. Male: legs yellow, at most the very base of femora 1 and 2 black and femur 3 black on its basal 1/4. Female: legs entirely yellow; antennae usually dis- tinctly orange with 3rd segment some- what darkened above. 8-11 mm. Northern Europe, Northern Siberia, Nearctic › Syrphus attenuatus Hine 8.b. Lateral margins of tergites partly black and partly yellow. Male: femora 1 and 2 black on basal 1/3 of their length, figure 758. Syrphus nitidifrons, head of male. femur 3 black for 2/3 of its length. figure 759. Syrphus nitidifrons, habitus of Female: legs yellow with all tarsi dark- female (Verlinden). ened, tarsus 3 almost black. 8-11 mm. Northern Europe › Syrphus admiran- dus Goeldlin 6.a. Metatars 2: a portion of the bristles on the ventral surface black. Male: eyes meeting above the antennae for a dis- tance longer than that between the anterior and posterior ocelli › 7 6.b. Metatars 2: all bristles and hairs on TEMNOSTOMA the ventral surface orange-yellow. Male: eyes meeting on frons for a distance equal to or longer than the distance between the anterior and posterior Introduction ocelli. 8-11 mm. Alps, may also occur at lower altitudes. › Syrphus auberti Temnostoma dwell in damp deciduous Goeldlin forests, where they bask on leaves and twigs and visit the flowers of understorey 7.a. Frons, immediately posterior to the herbs. They exhibit territorial behaviour, lunulae, yellow; sternites yellow. Male: chasing any larger in the immedi- femur 3 yellow. Female: frons shiny yel- ate vicinity. The larvae of Temnostoma live low and entirely covered with silver- in old dead wood of deciduous trees. grey dusting for all but the posterior 1/4 Derksen (1941) indicates that metamor- of its length; posterior 1/4 of the frons, phosis of T. bombylans takes two years and including the ocellar triangle, shiny the larvae inhabit stumps of trees felled black › 8 seven to eight years previously.

217 Recognition 2.a. Tergite 3-4 and often tergite 2 with a pair of yellow stripes › 3 Temnostoma are convincing wasp mimics. 2.b. Tergite 2-4 with a single yellow stripe, Flying T. vespiforme and T. apiforme even at the hind margin at most a small stripe mimic the erratic flight patterns of wasps. of grey dust without clear margin. However, once sitting they are quickly Northern Europe, Siberia. › Temnostoma recognisable as by their short sericomyiaeforme Portschinsky antennae and unfolded wings. The hover- Sphecomyia is similar to 3.a. Tergite 2-4: front and hind yellow Temnostoma but has long antennae. band broadly connected at the side mar- Spilomyia is superficially like Temnostoma gin, the width of the black band in but has striped eyes and two yellow between 2-2.5 times smaller than the stripes on the thoracic dorsum before the width of the anterior yellow band. › 4 scutellum. Key based on Krivosheina 3.b. Tergite 2-4: front and hind yellow (2004) and Bartsch et al. (2009b). band separated at the side margin, at most joined by a small yellow strip. › 5 Key 4.a. Thoracic dorsum: the yellow spot before the postalar lobes reaches and 1.a. Thoracical dorsum with triangular covers the postalar lobes, which are part- yellow spots just before the postalar ly yellow; the yellow streak at suture of lobes (figure 760) › 2 the thoracic dorsum uninterrupted. 14- 1.b. Thoracical dorsum black just before 17 mm. Northern and central Europe, in postalar lobes (figure 761) › 6 Asia into Japan, Nearctic region › Linnaeus entire 4.b. Thoracic dorsum: the yellow spot before the postalar lobes does not reach 760. the postalar lobes, which are black; the yellow streak at the suture interrupted in the middle. 14-17 mm. Northern and Central Europe › Temnostoma merid- ionale Krivosheina and Mamaev

yellow

interrupted

761.

black

figure 760. Temnostoma vespiforme, thoracic dorsum. figure 761. Temnostoma apiforme, thoracic figure 762. , habitus dorsum (Verlinden). of male (Verlinden).

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