## 1 Introduction  
Insect pests are recognized as significant drivers of forest ecosystems' disturbance worldwide, in addition to other biotic and abiotic factors [1]. Among the plethora of harmful insect taxa, several bark and wood-boring beetles represent a serious threat for the forest health and economic exploitation of forest resources, not only due to the direct damage they cause [2; 3], but also for the pathogens they may transmit as vector insects [4; 5]. Jewel beetles (Coleoptera: Buprestidae) are included within these damaging organisms [3]. Most buprestid species are saproxylic, in which their progeny develops under the bark of decayed and dead trees. However, some species colonize living stressed and weakened trees [6; 7; 8; 9], causing the death of the host, due to the direct feeding activity of the larvae. One of the most destructive species is the emerald ash borer _Agrilus planipennis_ Fairmaire, an Asian invasive species that causes serious damage to ash species (_Frazinus_ spp.) native to North America. Since its first detection in Michigan and Ontario in 2002 [10], _A. planipennis_ has caused the mortality of hundreds of millions of ash trees, leading to losses of billions of dollars in the United States and Canada in terms of preventive measures and management [11; 12]. Under this scenario, vast research has been devoted during the last two decades to develop efficient management strategies against this destructive species, with relevant works focused on its chemical ecology. In this regard, it has been elucidated that some host bark sesquiterpenes, the host green leaf volatile (\(Z\))-3-hexen-1-ol, and a female-released pheromone, namely (\(Z\))-3-dodecen-12-olide, are involved in the attraction of males and females to sticky green and purple prism traps [comprehensively reviewed in [13]], with each sex displaying a marked preference for a concrete visual-olfactory cue combination. To the best of our knowledge, fifteen native jewel beetle species are regarded as damaging agents in different areas of Europe, especially affecting broadleaf trees [3]. In the Mediterranean Basin, the flathead oak borer (FOB) _Conebus undatus_ (F.) is considered as a primary pest species that attacks apparently healthy cork oaks (_Quercus suber_ L.) [3], and even though it does not directly kill the tree, severe infestations may weaken the host and favor the incidence of more noxious organisms [14]. The species shows a biennial lifecycle [15; 16], although it has been suggested that it may complete the larval development in a single year [17]. Females lay eggs in bark crevices from May to September, and after hatching, larvae burrow into the cork and build long (up to 2 m) and wide (3-5 mm) S-shaped vertical galleries in the cork-generating layer [3]. As a consequence, cork-producing tissues are damaged and the quality of the harvested material drastically decreases, leading to severe economic losses for the cork industry. For instance, in the region of Extremadura (Spain), the annual economic loss in cork production attributable to _C. undatus_ has been estimated to be EUR 5 million [14]. Currently, no effective management measure against the FOB has been implemented, and only silvicultural practices, such as removing the bark from the affected oak, are useful for detecting the presence of larvae underneath [14]. Therefore, the development of novel efficient tools for surveillance and/or mass trapping of dispersing adults is urgently needed. At present, the sole monitoring tool can be described as a blend comprising five host green leaf volatiles in combination with sticky purple prism traps [18]. This trapping approach was demonstrated to be more effective than the use of other lures (ethanol and a blend of nonanal, decanal, and geranylacetone), regardless of the trap employed (purple prism or Lindgren multiple-funnel trap). Interestingly, these host volatiles have been proven to be attractive for the congeneric species _Conebus florentinus_ (Herbst) under laboratory conditions [19].