STUDI SULLE LARVE DEI COLEOTTERI DITISCIDI V. Note morfologiche sulle larve di tre specie del genere Laccophilus Leach

Abstract

MORPHOLOGICAL NOTES ON THREE SPECIES OF GENUS Laccophilus LEACH

The author deals with the morphology of the three larval instars of Laccophilus testaceus Aubè (subf. Laccophilinae) and the characters that differentiate the second and thitd instar larvae of Laccophilus minutus L. and Laccophilus variegatus Ger.m. Two keys are here proposed to second and third instar larvae of these species.

The larval morphology of L. testaceus Aubè showes, in comparison with that of the species treated in the preceding papers of the author, some peculiar characters (mainly the shape of fronto-clypeal region and the presence of two setae only on the clypeal edge, in the fìrst instar larva); some other characters of the three larval instars have been on the contrary found in one or another of the species of the subf. Colymbetinae, that the author has previously treated.

The examined specimens were gathered in Centrai and Southern Italy; their specifìc identifìcation was verifìed with rearing.

È trattata la morfologia esterna dei tre stadi larvali di Laccophilus testaceus Aubè (Dytiscidae, Laccophilinae), ponendo particolare attenzione ai caratteri che subiscono variazioni nel corso dello sviluppo larvale. Si segnalano, inoltre, i caratteri di maggior interesse sistematico delle larve di II e di III età di altre due specie del Genere, Laccophilus minutus L. e Laccophilus variegatus Germ.