Amasa

Barnouin, Thomas, Soldati, Fabien, Roques, Alain, Faccoli, Massimo, Kirkendall, Lawrence R., Mouttet, Raphaëlle, Daubree, Jean-Baptiste & Noblecourt, Thierry, 2020, Bark beetlesand pinhole borers recently ornewly introduced toFrance (Coleoptera Curculionidae, Scolytinae and Platypodinae), Zootaxa 4877 (1), pp. 51-74 : 55

- Amasa sp. near truncata (Erichson)

( Figs. 1A, 1B )

Distribution and identification. The genus Amasa is native to Asia and Australasia ( Wood & Bright 1992) and comprises at least 53 species ( Wood & Bright 1992; Smith et al. 2020a, 2020b). Little is known of the biology of most species, but in Australia and Malaysia most recorded hosts are in the Myrtaceae ( Browne 1961; Wood & Bright 1992).

Based on photographs, Amasa specimens from France appear to belong to the same species that was collected in Spain in 2009. Furthermore, the both European populations appear to be the same as the Amasa now established in Eucalyptus plantations in New Zealand, Brazil, Uruguay and Chile ( Milligan 1969; Zondag 1977; Flechtmann & Cognato 2011; Gómez et al. 2017; Kirkendall 2018). The single Spanish specimen from Cádiz was identified as the southeast Asian species A. resecta (Eggers) ( Viñolas & Verdugo 2011) , possibly based on photographs of said species (https://www.insectimages.org/browse/detail.cfm?imgnum=5593028). Details of the declivity differ, however. A mtDNA sequence from the COI gene of a French specimen was 100% identical to an unidentified bark beetle sequence in the BOLD database from New South Wales, Australia (M.A. Auger-Rozenberg, pers. comm.: http:// v3.boldsystems.org/index.php/Public_RecordView?processid=SBGB053-03), meaning that the French specimen is an Australian species (and morphologically it is clearly an Amasa ). The New Zealand Amasa and South American populations were all identified as Amasa truncata (Erichson) . This appears now to be incorrect. Bark beetle taxonomists Roger A. Beaver and Milos Knižek (both, pers. comm., April 2020) have examined the holotype, which has noticeably longer setae on the declivity and more pronounced swellings on the odd-numbered declivital interstriae. These differences can be seen in the PaDIL photographs of Amasa truncata (http://www.padil.gov.au/pests-anddiseases/pest/main/141313). Amasa sp. near truncata does not match photos or descriptions of the any of other four species of Amasa recorded from Australia, nor does the Amasa now in South America ( Flechtmann & Cognato 2011) , but there are at least four more undescribed species in the genus present in that country that are similar to and have been confused with A. truncata (R. A. Beaver, pers. comm., April 2020). The invasive species, then, could well be one of those undescribed cryptic species.

Many adults of an Amasa species were trapped throughout the summer 2018 in the arboretum of Villa Thuret in Antibes, then again in 2019; none were trapped in the nearby Garoupe forest although a number of similarly baited traps were deployed there. In 2019, specimens were caught on the island of Sainte Marguerite, ca. 8 km away. These data show that this species has become established in that region.

New records. ALPES-MARITIMES – Antibes, Villa Thuret, interception traps baited with ethanol 100%, (-) α-pinene and a blend of longhorn beetle pheromones: 3 ind. from 27.VI. to 18.VII.2018, 24 ind. from 19.VII. to 08.VIII.2018, 17 ind. from 29.VIII. to 19.IX.2018, and 10 ind. from 20.IX to 11.X. 2018, URZF leg.; ibidem, from 21.V. to 22.X.2019, 22 ind., URZF leg.; Cannes, Sainte- Marguerite island , interception traps baited with ethanol 100%, (-) α-pinene, and a pheromone blend for longhorn beetles, from 24.V. to 14.VI.2019, 3 ind., URZF leg .

Damage and infestation risk. Amasa species have mandibular mycangia which transport symbiotic fungi belonging to Raffaelea (previously reported as Dryadomyces ), a genus that includes a number of pathogenic species ( Gebhardt et al. 2005; Hulcr & Stelinski 2017). However, there are no reports yet of significant damage being caused by either A. truncata or A. sp. near truncata (reviewed in Kirkendall 2018).

Figures

FIGURE 1. Amasa sp. near truncata (Erichson) (2.5 mm). A. dorsal view; B. lateral view. Cyclorhipidion distinguendum (Eggers) (2.9 mm). C. dorsal view. Dryocoetes himalayensis Strohmeyer (2.7 mm). D. dorsal view; E. lateral view. Length of specimens in brackets. (Photos: Olivier Denux, Fabien Soldati & Thomas Barnouin).