Corresponding author: Nikita Vikhrev (
Academic editor: Martin Hauser
An analysis of key characters for the separation of
The
The examined material is restricted to Eastern Europe, Transcaucasian region and Siberia, and do not include specimens collected in Western Europe. However, the proposed key characters are expected to be suitable for west-european specimens as well, because there is no gap in natural habitats of
This analysis is based on the following material:
Morphological structures are abbreviated as:
On several occasions colleagues have expressed doubts that
1 | The longest aristal hairs distinctly longer than width of postpedicel |
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– | The longest aristal hairs slightly longer than width of postpedicel |
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This character was used as the main one by all the cited authors except for |
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I agree that the aristal hairs are somewhat longer in |
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– | Female: long aristal hairs reaching apical third of arista |
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– | Female: long aristal hairs not reaching apical third of arista |
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I have not found this alternative to be more reliable or easier in use than the previous one. | ||
2 | Male: upper frons with several proclinate setulae |
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– | Male: upper frons with all setulae reclinate |
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First proposed by |
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3 | Male with |
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– | Male with |
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Used by |
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4 | Male |
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– | Male |
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Proposed by |
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5 | Male notopleuron bare |
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– | Male notopleuron with a few setulae |
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Proposed by |
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6 | Male: posterior part of scutum in posterior view densely dusted, without median vitta, with a pair of subshining narrow submedian vittae laterad to |
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– | Male: posterior part of scutum in posterior view mostly shining black, with a wide black median vitta |
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Proposed by |
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7 | Male abdomen with the median vitta on tergite 3 inconspicuous |
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– | Male abdomen with a conspicuous black median vitta on tergite 3 |
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Proposed by |
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8 | Male body length usually 7–7.5 mm, rarely 6–8 mm |
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– | Male body length usually 8.5–9 mm, rarely 6.5–9.5 mm |
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– | Female body length usually 6.5–7.5 mm |
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– | Female body length usually 7.5–9 mm |
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In spite of rare cases of overlapping, this character is at least as reliable as, and much easier to use than the width of the aristal hairs. The body size difference was also mentioned by |
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9 | Female: postsutural part of scutum in posterior view with the median vitta indistinct, or if more or less distinct then narrow, widened only posteriorly |
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– | Female: postsutural part of scutum in posterior view with the undusted median vitta distinct, uniformly wide throughout, occupying all the area between acrostichal rows |
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Proposed by |
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10 | Female abdomen with the median stripe narrow, often absent |
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– | Female abdomen with a broad median stripe |
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Again proposed by |
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11 | Female: |
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– | Female: |
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Used by |
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12 | Female: dusting on thorax and abdomen yellow with a slight brown tint |
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– | Female: dusting on thorax and abdomen grey with a slight yellow tint |
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Proposed by |
Female scutum in posterior view.
The distribution of these species in mountain areas seems sporadic and there aren’t enough reliable records. In the Austrian Alps, in the Oetz Valley, both species overlap at about 1500 m asl. Below this level, in the coniferous and broad-leaf forest zone,
1 | 2 | |
– | 3 | |
2 | Femora black, tibiae more or less darkened basally. Mid tarsomeres 3–4 each with a row of pale |
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– | All femora and tibiae yellow, at most fore femur slightly darkened. Mid tarsomeres 3–4 each with the row of pale |
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3 | In lateral view, |
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– | In lateral view, |
1 | Legs entirely black. Palearctic, including Transcaucasian region | 2 |
– | Legs partly or entirely yellow. Caucasus | 3 |
2 | Postsutural part of scutum in posterior view with the median vitta indistinct ( |
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– | Postsutural part of scutum in posterior view with the undusted median vitta distinct, uniformly wide throughout, occupying all the area between |
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3 | Femora black, tibiae darkened basally | |
– | Femora and tibiae yellow |
I thank Oleg Kosterin (Novosibirsk), Adrian C. Pont (Oxford) and Andrey Ozerov (Moscow) who suggested several very useful corrections.