Trap Style, Bait, and Height Deployments in Black Walnut Tree Canopies Help Inform Monitoring Strategies for Bark and Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae)

Abstract

Knowledge about which bark and ambrosia beetle species are active and at what heights in black walnut canopies is not well understood. Neither is the role of these beetles in spreading Thousand Cankers Disease. To assist with future planned research, which will assess the extent to which these beetle species are associated with Geosmithia morbida Kolařík, Freeland, Utley, and Tisserat (Ascomycota: Hypocreales: Bionectriaceae), experiments were undertaken to monitor bark and ambrosia beetles in urban landscapes and parks in Tennessee between 2011 and 2013. Within mature walnut tree canopies, sticky panel, modified soda bottle, and Lindgren traps were deployed at different heights, with and without ethanol as an attractant and with and without walnut stem sections, or in situ limbs that had been girdled or injection with ethanol to simulate stressed tree tissues. Bark and ambrosia beetle species (Coleoptera: Curculionidae: Scolytinae) collected in greatest abundance included Ambrosiodmus rubricollis (Eichhoff), Ambrosiophilus atratus (Eichhoff), Cnestus mutilatus (Blandford), Dryoxylon onoharaense (Murayama), Euwallacea validus (Eichhoff), Monarthrum fasciatum (Say), Monarthrum mali (Fitch), Xyleborinus saxesenii (Ratzeburg), Xyleborus affinis Eichhoff, Xyleborus ferrugineus (Fabricius), Xylosandrus crassiusculus (Motschulsky), and Xylosandrus germanus (Blandford). C. mutilatus, X. saxesenii, and X. crassiusculus were more active higher in trees than most other species and were strongly attracted to ethanol via all means of lure deployment. C. mutilatus, which were captured from April through October and increased in abundance across the 3-yr study, were most abundant in late May with a second activity period in late August.

Ambrosia beetle response to ethanol concentration and host tree species

“…dispar and X . crassiusculus do not simultaneously attack the same trees or logs despite their overlapping flight activity (Frank & Ranger, 2016; Klingeman et al., 2017; Ranger et al., 2015; Rassati, et al., 2016). Other ambrosia beetles such as Trypodendron spp.…”

“…The 5% concentration was selected based on previous host selection and colonization studies on X. saxesenii and Xylosandrus spp. (Ranger et al, 2018;Rassati et al, 2020), and the 90% concentration was selected because it is highly attractive to many ambrosia beetle species (Klingeman et al, 2017). The aqueous ethanol solution was poured into the drilled hole, which was then plugged with a silicon cap (Figure S1).…”

Recent advances toward the sustainable management of invasive Xylosandrus ambrosia beetles

“…Ethanol-baited traps are the predominant method for monitoring ambrosia beetle populations, including Xylosandrus spp. in ornamental nurseries (Reding et al, 2010(Reding et al, , 2011(Reding et al, , 2015, forests (Hauptman et al 2019;Martínez et al 2019;Marchioro et al 2020), and urban landscapes and parks (Klingeman et al 2017;Gugliuzzo et al 2019a). Several types of traps are commercially available, and homemade inexpensive bottle traps can be easily made and baited with lures (Egonyu and Torto 2018;Owens et al 2019b).…”

“…Several other factors can affect catch rates of Xylosandrus spp., including trap placement (Reding et al 2010;Klingeman et al 2017;Marchioro et al 2020;Miller et al 2020). Traps placed 0.5 m above the ground capture more X. germanus than those placed at 1.7 or 3.0 m (Reding et al 2010).…”

Trap Tree and Interception Trap Techniques for Management of Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae) in Nursery Production

“…Ethanol-baited intercept traps similar to previously published designs (Oliver et al 2004, Klingeman et al 2017 were constructed using 2-liter soda bottles hung upside down 1 m above the ground from metal rods. Each soda bottle had three window slots 8 cm wide by 15 cm tall cut in the bottle side to allow beetle entry.…”