Redescription and review of the most abundant conehead in Italy: Acerentomon italicum Nosek, 1969 (Protura: Acerentomidae)

Abstract Acerentomon italicum is the most abundant species of Protura in Italy. In this paper, A. italicum is redescribed according to the most recent revision of diagnostic characters (morphometry, porotaxy), examining the type material and 59 specimens from 11 different localities in our collection. For some characters, scanning electron microscope (SEM) pictures are presented. An updated detailed catalogue extracted from the authors’ database is provided: A. italicum is reported from 91 Italian localities (mainly from Northern Italian regions) in a total of 520 ♂♂, 669 ♀♀, 28 pre-imagines, 69 maturi junior, 25 larvae II, four larvae I and eight undetermined. Few specimens were collected in Switzerland (two, about 5 km away from the Italian border), Austria (three), Slovenia (one) and Corsica (eight). The entire data set is analysed for information on phenology (juveniles detectable every month in Liguria and Tuscany, but only during spring–summer in the remaining regions of Northern Italy) and sex ratio (M:F = 0.78) of this species. A. italicum was collected in localities from 0 to 2000 m above sea level in the soil and litter of pure and mixed forest. The geological substratum, when recorded, was limestone, quartz/mica schists and conglomerates. The DNA barcode is newly provided for 21 representatives from three Italian populations of A. italicum.