Parablops aetnensis Rottenberg, 1871: 256

Piccini, Irene, Cristiano, Luca, Pietro, Viviana Di, Bonelli, Simona & Biscaccianti, Alessandro B., 2021, A revision of distribution, ecology and conservation issues of the threatened comb-claw beetle Gerandryus aetnensis (Coleoptera: Tenebrionidae, Alleculinae), Fragmenta entomologica 53 (1), pp. 13-20 : 14-16

Parablops aetnensis Rottenberg, 1871: 256 .

Material examined. Italy, Piedmont: Cottian Alps, Val Clarea, Chiomonte ( TO) , Mt. Cappella Bianca S, loc. La Ramats, 1100 m, 25.X.2019, window-flight trap on Castanea sativa Mill., I. Piccini and V. Di Pietro lgt, 1♂ ( LCR) ; Cottian Alps, Val Chisone, Fenestrelle ( TO) , 1200 m, 30.V.2000, F. Angelini lgt, 1♀ ( MZSF) ; Tuscany: Vagli di Sopra ( LU) , 900 m, 21.V.1998, chestnut woods, F. Angelini lgt, 1♂, ( MZSF) ; Latium: Simbruini Regional Park ,

Filettino ( FR), 1980-2000, F. Angelini lgt (specimens no longer available, F. Angelini pers. com.); Abruzzo: Gran Sasso National Park , Pietracamela ( TE) , Prati di Tivo, 1980-2000, beech forest, F. Angelini lgt (specimens no longer available, F. Angelini pers. com.); Majella National Park , Pratola Peligna ( AQ) , Colle delle Vacche , 1099 m, 12.X.2018, pitfall trap in burned pine woods, A.B. Biscaccianti lgt, 1♀ ( ABB) ; Campania: Cilento National Park , Camerota ( SA) , between Punta del Cavaliere and Vallone Sant’Iconio , 150 m, IX.2008, pine woods, A.B. Biscaccianti lgt, 1♀ ( ABB) ; Calabria: Aspromonte National Park , San Luca ( RC) , Pietra Mazzulisa, Bosco Afreni , 1419 m, 3.X.2016, A.B. Biscaccianti, F. Manti and E. Castiglione lgt, 1♂ ( ABB) ; Sicily: Mt. Etna , Montelaguardia ( CT) , 720 m, 3.XI.1948, F. Hartig lgt, 1♀ ( MZUR) ; Peloritani Mts. , Montalbano Elicona ( ME) , Bosco di Malabotta, loc. Portella di Croce Mancina , 1237 m, 23.X.2020, remains in a cavity on Quercus cerris L., A.B. Biscaccianti and E. Giuliano Grimaldi lgt, 1♀ ( ABB) .

The specimen from Piedmont was sampled in a thermophile area in the Val Clarea (Fig. 1) using windows-flight traps baited with ethanol 90°, placed on hollow-trees and active from July to October, recharging intervals of one month. The site is an abandoned chestnut orchard with Quercus L. and Prunus L., clearings and open areas interspersed, southern exposure. An adult was caught during the last sampling session (end September – end October). In the Majella National Park (Abruzzo) the sampling site was located in a core area of forest fire that affected the south-western side of the Morrone mountain chain. Two sampling plots were selected in the area, one in a burned beech forest and the other in a burned reforestation of black pine ( Pinus nigra J.F.Arnold subsp. nigra ) (Fig. 2). The study area was investigated for two years after fire (2018 and 2019) using both aerial traps on the canopy, baited with a mixture of red wine, beer and ripe fruit, and pitfall traps baited with vinegar, active from June to October, recharging intervals of one month. Gerandryus aetnensis was caught only the first year, during the last sampling session (mid September – mid October), with a pitfall trap in the pine woods. The specimen from Cilento National Park (Campania) was collected by beating dead branches of Pinus halepensis Mill. subsp. halepensis in a xeric Mediterranean environment, unusual for G. aetnensis . The site, in fact, is an apparently autochthonous coastal Aleppo pine woods, where the discovery of this species was rather unexpected. Unfortunately, the area where the species was detected has been largely deforested in 2017. The sampling site in the Aspromonte National Park (Calabria) was located in a well preserved old-growth forest of Calabrian pine ( Pinus nigra J.F.Arnold subsp. laricio Palib. ex Maire ) (Fig. 3), characterized by the presence of several veteran trees of Quercus petraea (Matt.) Liebl. subsp. austrotyrrhe ica Brullo, Guarino & Siracusa and a large amount of deadwood. In this place, G. aetnensis was caught with a pitfall trap baited with vinegar and positioned inside a hollow-oak.

In order to better understand the biology and ecology of G. aetnensis , not yet well known, one of us ( ABB) visited a site in northern Sicily where the species was recently discovered: Bosco di Malabotta ( Baviera 2011 and pers. comm.). The site investigated is a well preserved ancient Turkey-oak mountain forest, with an abundance of old, senescent and dead trees of Turkey-oak, beech, maple, chestnut and other species. Remains of G. aetnensis were found inside a hollow-oak, as expected.

We calculated the extent of occurrence ( EOO) and the area of occupancy ( AOO) for the species at global level and Italian level, in order to evaluate the most appropriate risk category for the IUCN Red List assessment, and the relevant criteria to apply. EOO, measured by a minimum convex polygon (excluding sea and islands), resulted of 70,318 km 2 at global level. The estimate of AOO is scaled using 2 x 2 km grid cells for all records collected after 1999, and 10 x 10 km grid cells for older records (ante 2000), since a certain degree of uncertainty exists regarding the exact location and extension of the latter, which however we retain not to exclude, all but one (Gravina di Catania, see below). The result is a total and Italian AOO of 752 km 2 ( Table 1; Fig. 4 ) and 732 km 2 respectively.

Figures

Fig. 4 – Geonemy and area of occupancy (AOO) of Gerandryus aetnensis (Rottenberg, 1871). Main figure, species geonemy; boxes, AOO calculation. Symbols: triangles, new records; circles, literature records; black cross, extinct in the site; yellow, records ante 2000; green, records post 1999 (main figure); large squares, 10 x 10 km grid cells; small squares, 2 x 2 km grid cells (boxes).