Journal of Pest Science (2019) 92:281–297 https://doi.org/10.1007/s10340-018-0997-6 ORIGINAL PAPER Multi‑component blends for trapping native and exotic longhorn beetles at potential points‑of‑entry and in forests Jian‑ting Fan1,2 · Olivier Denux1 · Claudine Courtin1 · Alexis Bernard1 · Marion Javal1 · Jocelyn G. Millar3,4 · Lawrence M. Hanks5 · Alain Roques1 Received: 14 February 2018 / Revised: 26 May 2018 / Accepted: 28 May 2018 / Published online: 7 June 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract The accidental introduction of exotic wood-boring cerambycid beetles represents an ever-increasing threat to forest biosecu- rity and the economies of many countries. Early detection of such species upon arrival at potential points-of-entry is challeng- ing. Because pheromone components are often conserved among related species in the family Cerambycidae, we tested the generic attractiveness of diferent blends of pheromones composed of increasing numbers of pheromone components at both potential points-of-entry and in natural forests in France during 2014–2017. Initially, two diferent four-component blends were compared, one composed of fuscumol, fuscumol acetate, geranylacetone, and monochamol, and the other composed of 3-hydroxyhexan-2-one, anti-2,3-hexanediol, 2-methylbutanol, and prionic acid. In a second step, host volatiles (ethanol and [-]-α-pinene) were added, and fnally, we tested the efectiveness of a mixture of all eight pheromone components with the two host volatiles. Overall, 13,153 cerambycid beetles of 118 species were trapped. The 114 native species trapped represent 48% of the French fauna, including more than 50% of the species in 25 of the 41 cerambycid tribes. At potential points-of-entry, captures included 2960 cerambycids of 49 species, including three exotic Asian species, two of which had never been reported previously in Europe. In forests, attraction to the four-component blends varied with their composition. Adding host volatiles did not change the overall attraction except for the species Phymatodes testaceus, which showed a fourfold increase in captures. Placing the two four-component blends on the same trap resulted in signifcant increases in the number of species and individuals captured compared to captures by traps baited with each blend individually. Finally, the eight-component pheromone blend was found to be as attractive as the combination of the two four-component blends hung together on the same trap, without apparent antagonistic efects. This fnding suggests that use of multi-component lures may help to minimize the costs and manpower required to detect exotic and potentially invasive species. Keywords Cerambycidae · Early detection · Multi-component pheromone lures · Exotic · Trapping · Ports Key message Communicated by J.D. Sweeney. • Early detection of exotic cerambycid beetles upon arrival at points-of-entry is a major challenge for regulatory Special Issue on Invasive Pests of Forests and Urban Trees. agencies. Electronic supplementary material The online version of this • The parsimony in pheromone structures used by a num- article (https​://doi.org/10.1007/s1034​0-018-0997-6) contains ber of cerambycid species worldwide suggested that supplementary material, which is available to authorized users. * Alain Roques 3 Department of Entomology, University of California, [email protected] Riverside, CA 92506, USA 4 Department of Chemistry, University of California, 1 INRA UR 633 Zoologie Forestière, 2163 Avenue de la Riverside, CA 92506, USA Pomme de Pin, 45075 Orléans, France 5 Department of Entomology, University of Illinois 2 School of Forestry and Biotechnology, Zhejiang Agriculture at Urbana-Champaign, Urbana, IL 61801, USA and Forestry University, Lin’an, China Vol.:(0123456789)1 3 282 Journal of Pest Science (2019) 92:281–297 multi-component blends of pheromones could be used lure combinations improve trapping efciency without sig- as efective trap baits, while minimizing costs and man- nifcant antagonistic efects. power. To date, most trapping trials carried out within or near to • Results showed that the number of species detected at a ports and other points-of-entry for international cargo pri- site was maximized by a blend of eight pheromone com- marily have tested single lures rather than blends of attract- ponents, together with plant volatiles, without signifcant ants (Brockerhof et al. 2006) and have focused on bark bee- antagonistic interactions among components. tles rather than cerambycids (Rabaglia et al. 2008). However, • Trapping of native species around ports and airports indi- Rassati et al. (2014) compared attraction of bark beetles to cated their potential to be moved as exports. single versus multiple components in Italian seaports and found that the multi-lure trap was as efective as the sum of the single-lure traps, with no evidence of any negative interactions among the tested compounds, suggesting that Introduction efective monitoring with multi-lure traps may be feasible. Recent advances in the identifcation of cerambycid pher- Exotic wood-boring beetles, especially those in the families omones are now ofering analogous opportunities for devel- Cerambycidae and Buprestidae, and the subfamily Scolyti- oping multi-lure blends aimed at attracting multiple species nae of the Curculionidae, represent serious threats to for- simultaneously (Wong et al. 2012). Sex and aggregation-sex est biosecurity and the economies of all forested countries. pheromones are known for several hundred cerambycid spe- These insects usually arrive as immatures sequestered within cies (reviewed by Millar and Hanks 2017), and pheromone wood, wood products, or wooden packing material such as structures are frequently highly conserved among related pallets, crating, and dunnage (Brockerhof et al. 2006; Lieb- species (Hanks and Millar 2013, 2016). For example, pher- hold et al. 2012; Rassati et al. 2014), and increasingly, ship- omones of many species in the subfamily Cerambycinae ments of nursery plants and bonsais (Roques 2010; Liebhold are composed of 3-hydroxyalkan-2-ones, 2-hydroxyalkan- et al. 2012). Therefore, air, sea, and river ports, and associ- 3-ones, or 2,3-alkanediols, whereas pheromones of many ated facilities for handling and storing international cargos, species in the subfamily Lamiinae consist of hydroxyethers are likely points-of-entry for exotic wood-boring beetles. and related compounds, the terpenoid fuscumol ([E]- The problem is exacerbated by the fact that newly observed 6,10-dimethylundeca-5,9-dien-2-ol) and its corresponding introductions and establishments usually are due to “emerg- acetate, while fuscumol also is used as a pheromone by spe- ing” species, i.e., those that have never been reported as cies in the subfamily Spondylidinae (reviewed in Hanks and introduced elsewhere, and which are not signifcant pests in Millar 2016). Furthermore, the use of the same compounds their native range (Seebens et al. 2018). Such species usually by species on multiple continents (e.g., Wickham et al. 2014 are not subject to regulatory measures because their invasive in China; Sweeney et al. 2014 in Russia; Hayes et al. 2016 potential has not been recognized. The development of new in Australia; Silva et al. 2017 in Brazil) has demonstrated strategies to detect such unanticipated, unregulated species the potential for exploiting such compounds to detect exotic as early as possible is essential in order to implement rapid species upon their arrival on another continent. and efective eradication measures (Rassati et al. 2014). Species which share dominant pheromone components Countries such as Australia (Bashford 2008), New Zea- appear to use several mechanisms to avoid cross-attraction, land (Brockerhof et al. 2006), the USA (Rabaglia et al. such as difering in seasonal and/or daily activity period, 2008), and Italy (Rassati et al. 2015) have recently imple- or use of minor pheromone components to create species- mented strategies to enhance the early detection of alien specifc blends (Hanks and Millar 2013; Mitchell et al. 2015; wood-boring beetles based on baited traps deployed in ports Meier et al. 2016). These fndings have resulted in the devel- or other high-risk sites. Such traps should ideally be ef- opment and optimization of methods for using pheromone- cient at low population densities and should target multiple based attractants to detect many cerambycid species and to species of diverse taxa simultaneously, both because it is characterize cerambycid communities in North America impossible to predict which species may arrive (Rassati et al. (Graham et al. 2010; Allison et al. 2011, 2014; Mitchell 2014) and because costs escalate rapidly with increasing et al. 2011; Hanks and Millar 2013; Handley et al. 2015; numbers of traps deployed. Moreover, because the practi- Webster et al. 2016). calities of installing traps in safe and suitable places in such Several experiments carried out in natural landscapes in sites of high activity are limiting, it is essential to minimize North America have shown that use of multi-component the number of traps within each port-of-entry. Traps baited blends of cerambycid pheromones as trap baits may be with blends of pheromones and related attractants would both feasible and efective (Hanks et al. 2012, 2018; Millar thus represent a major improvement in currents protocols et al. 2018). Partial inhibition was noted for a few species, (Brockerhof et al. 2006; Hanks et al. 2012) but only if the with