First record of Ambrosiodmus (Hopkins, 1915) (Coleoptera: Curculionidae, Scolytinae) in Europe

Abstract

In early April 2009, many specimens of Ambrosiodmus (Hopkins, 1915) (Coleoptera: Curculionidae: Scolytinae), a genus new to Europe, were found overwintering in a living horse chestnut tree (Aesculus hippocastanum L.) in the botanic garden of Padova (NE Italy) (45°23’ N, 11° 52’ E). In October 2009, about 80 peach trees growing in an orchard close to Verona (Alpo di Villafranca, NE Italy) (45°22’ N, 10° 55’ E) were found infested by the same insect. In both cases, the insects were infesting the tree sapwood infected by honey fungus (Armillaria mellea (Vahl) Kummer). Moreover, in the first week of October one specimen was collected also in a pheromone trap baited with ipsdienol and ipsenol and set up in the international harbour of Venice (Marghera, 45°27’ N, 12° 15’ E). Subsequent morphological analyses ascribed the collected specimens to the species A. rubricollis (Eichhoff, 1875), an ambrosia beetle of Asian origin. The infested trees were submitted to sanitation felling and burnt. Some infested log was placed in a transparent and ventilated plastic cage, kept under laboratory conditions (21±1 °C, 70% r.h., and L16:D8 photoperiod) waiting for insect emergence. Emerging adults were removed daily, identified and sexed by morphological features. The rearing gave several thousands of adults, with a female:male ratio of about 40:1.

Ambrosiodmus rubricollis (Eichhoff) (Coleoptera; Curculionidae; Scolytinae) associated with young Tasmanian blue gum trees

“…The specimens collected were identified as Ambrosiodmus rubricollis (Eichhoff), the only member of the genus found in Europe (Faccoli et al, ; Kirkendall & Faccoli, ; Rassati, Lieutier, & Faccoli, ). This insect can be distinguished from other European Xyleborini by the asperities covering most or the entire pronotal surface, a distinctive diagnostic feature found in the genus Ambrosiodmus (Faccoli et al, ; Wood, ).…”

“…The specimens collected were identified as Ambrosiodmus rubricollis (Eichhoff), the only member of the genus found in Europe (Faccoli et al, ; Kirkendall & Faccoli, ; Rassati, Lieutier, & Faccoli, ). This insect can be distinguished from other European Xyleborini by the asperities covering most or the entire pronotal surface, a distinctive diagnostic feature found in the genus Ambrosiodmus (Faccoli et al, ; Wood, ). The specimens presented characteristic taxonomic features such as the number of denticles on the lateral margins of protibiae and metatibiae, absence of a definite row of serrations on the anterior margin of the pronotum, rounded (on both faces) first segment of the antennal club and one pair of preoral mycangia at the base of the mandibles, behind the labrum, which are used to transport the fungal symbionts (Tagaki, ; You et al, ).…”

“…The species is now widespread in the mid‐Atlantic and south‐eastern United States of America (Bright, ; Lightle et al., ; Rabaglia, Dole, & Cognato, ), and is also reported as introduced in Australia (Gomez et al, ; Wood & Bright, ), although the website of the Australian Government Department of Agriculture and Water Resources (PaDIL) classifies A. rubricollis as absent from the country (McCaffrey, ). In Europe, it was first detected in Italy in 2009 (Faccoli et al, ), and, more recently, in neighbouring Slovenia (Hauptman, Rekanje, Pavlin, & Jurc, ).…”

“…Like other xylomycetophagous ambrosia beetles, A. rubricollis can utilize a broad range of reproductive host plants, with Faccoli et al () listing several broadleaved trees, shrubs and even conifers as hosts in its native and introduced ranges, and including members of the plant genera Abies , Acacia, Alnus, Biota, Carya, Castanea, Cinnamomum, Cornus, Cunninghamia, Diospyros, Fraxinus, Hovea, Ilex, Juglans, Ligustrum, Machilus, Morus, Myrica, Pinus, Populus, Prunus, Quercus, Rhus, Schima, Sophora, Terminalia and Vitex . In Italy, A. rubricollis was found causing a strong infestation on peach trees, Prunus persica L., and on horse chestnut, Aesculus hippocastanum L. (Faccoli et al, ). To our knowledge, this report is the first record of A. rubricollis associating with a eucalypt species worldwide, although a few other species of the Ambrosiodmus genus associate with Eucalypts (Lunz & de Carvalho, ; Wood & Bright, ).…”

“…Adults emerging from the logs were hand‐collected and kept in plastic vials until identification. At the INIAV’s laboratories, eight insects were identified to the species level with the keys of Gomez, Rabaglia, Fairbanks, and Hulcr (), Faccoli et al () and Hulcr and Smith ().…”