Forum Entomologi Italiani

Dim. 2,4 mm

Se non ho interpretato male i caratteri questo è con buona probabilità

Longitarsus ferrugineus (Foudras, 1860)

Se Davide o Lech confermassero ne sarei ben contento

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Roberto Vanzini

No, it is not Longitarsus ferrugineus. This species has very characteristic aedeagus with brown to black base and apex conical without elongate process:
http://www.cassidae.uni.wroc.pl/Europea ... gineus.htm

Aedeagus with elongate process as in your specimen have three species:

Longitarsus nigrofasciatus: http://www.cassidae.uni.wroc.pl/Europea ... ciatus.htm
Longitarsus nebulosus: http://www.cassidae.uni.wroc.pl/Europea ... ulosus.htm
Longitarsus brisouti: http://www.cassidae.uni.wroc.pl/Europea ... isouti.htm

We can exclude L. brisouti because this species has a constant dorsal pattern with elytra mostly yellow and black vitta along suture

L. nigrofasciatus and L. nebulosus are very similar and both have very variable pattern or have elytra uniformly ochraceous-yellow like your specimen. L. nebulosus is distinctly smaller than L. nigrofasciatus with length usally below 2.3 mm, while L. nigrofasciatus usually has length 2.5-3.2 mm but the smallest specimens have 2.3 mm. The best distinguishing character is structure of spermatheca, in L. nigrofasciatus ductus has at base 2-3 loops while in L. nebulosus it has only a half to one loop. L. nebulosus in Italy is southern species but and I have no knowledge if it was recorded from Lazio.

My opinion is L. nigrofasciatus.
Thank you so much

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Roberto Vanzini

Non sono molto bravo con il computer. Ho provato a fare un collage venuto abbastanza male
A sx. L. nigrofasciatus; al centro l'esemplare da determinare; a dx L. nebulosus

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Roberto Vanzini

You should be cleaned basal part of aedeagus prepared from your specimen. In L. nigrofasciatus, the lateral slats of the penis at the base do not touch in the middle, while in L. nebulosus they strongly converge in and touch in a short distance.