Forum Entomologi Italiani

Biblio.
- Chevin : Tenthredo succincta Lep. 1823, espèce valide .... in "Cahiers des Naturalistes Parisiens" 1983 - n.s. 39 - p.15/18

marginella (of Chevin) = thompsoni , succincta (of Chevin) = marginella

- Taeger : Zweiter Beitrag zur Systematik der Blattwespengattung Tenthredo (s.str.) in "Beitrag zur Entomologie" 1988 - 38(1) - p.103/153
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Saluti,

# 1569 ♂ & 1571 ♀ Captured at the same time & in the same place, Cne : Pontoise (Dépt. Val d' Oise - France) - 08.09.1986

Although not copulating I think that it is about the same species.

For the keys of determination of this sp., see : viewtopic.php?f=11&t=34877 & viewtopic.php?f=375&t=35433
See also marginella : viewtopic.php?f=11&t=35850
Therefore : thompsoni or marginella
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1571 ♀
According to the keys above this ♀ is a thompsoni, because the teeth of his saw are projecting.

See my photo (whence the contrasts were strongly stressed) of very bad quality (The magnification of my binocular lens being of X40, it would be necessary X70) where I added awkwardly the drawing of the ventral outline of a part of the saw.

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1569 ♂
According to Chevin, the punctuation of mesopleura is not easy to estimate.
The color of mandibles (ignored by Chevin) is difficult to use, except in the extreme cases :

- According to Taeger , the colors of the mandibles (apex excluded) are the following ones :

marginella : The base is always black.
thompsoni : The base is yellow, very rarely black (in that case they are stained with yellow towards the apex)
- The majority of captures, which we made, have mandibles stained with yellow, but neither on the base nor close to their apex.
It is thus generally difficult to recognize the species

We note in our ♂ :
- Its mandibles are, from their base, very mainly yellow.
- It was captured at the same time & in the same place that the thompsoni ♀ .
- Its date of capture is late (marginella appearing earlier - cf. Chevin)
For these reasons, this ♂ is a thompsoni

Finally :
Tenthredo (Tenthredo) thompsoni (Curtis 1839) ♂ & ♀ Anche catturato in Italia

Ciao,
D & JP Balmer