Novel, male-produced aggregation pheromone of the cerambycid beetle Rosalia alpina, a priority species of European conservation concern

Abstract

Several recent studies have demonstrated the great potential for exploiting semiochemicals in ecology and conservation studies. The cerambycid beetle Rosalia alpina represents one of the flagship species of saproxylic insect biodiversity in Europe. In recent years its populations appear to have declined substantially, and its range has shrunk considerably as a result of forest management and urbanization. Here, we collected volatile chemicals released by males and females of R. alpina. Analyses of the resulting extracts revealed the presence of a single male-specific compound, identified as a novel alkylated pyrone structure. In field bioassays in Slovenia, traps baited with the synthesized pyrone captured both sexes of R. alpina, indicating that the pyrone functions as an aggregation pheromone. Our results represent the first example of a new structural class of pheromones within the Cerambycidae, and demonstrate that pheromone-baited traps can provide a useful tool for sampling R. alpina. This tool could be particularly useful in the ongoing development of conservation strategies for the iconic but endangered Alpine longicorn.

The aggregation-sex pheromones of the cerambycid beetles Anaglyptus mysticus and Xylotrechus antilope ssp. antilope: new model species for insect conservation through pheromone-based monitoring

“…However, to date, although pheromones or likely pheromones have been identified from several hundred cerambycid species (Hanks and Millar 2016), pheromones have only been reported for a small number of rare or threatened species, such as a few species of the Prionus genus (Barbour et al 2011), Desmocerus californicus ssp. dimorphus (Ray et al 2014), Dryobius sexnotatus (Diesel et al 2017), Rosalia alpina (Žunič Kosi et al 2017), Phymatodes pusillus ssp. pusillus (Molander and Larsson 2018), and Plagionotus detritus ssp.…”

Identification of the Aggregation-sex Pheromone of the Cerambycid Beetle Phymatodes pusillus ssp. pusillus and Evidence of a Synergistic Effect from a Heterospecific Pheromone Component

“…Knowledge on the chemical ecology of longhorn beetles has seen significant expansion in recent years, particularly in terms of the number of pest, and potential pest, species with identified sex and aggregation-sex pheromones (Hanks and Millar 2016 ; Millar and Hanks 2017 ). However, more recently the possibility of exploiting pheromones as a tool to study rare species of conservation concern has been highlighted (Ray et al 2014 ; Žunič Kosi et al 2017 ). Studies of elusive saproxylic insects that are difficult to sample with conventional survey methods have shown that pheromone-based trapping methods can greatly facilitate ecological studies on these insects (Andersson et al 2014 ; Kadej et al 2015 ; Musa et al 2013 ; Oleksa et al 2015 ).…”

Environmentally vulnerable noble chafers exhibit unusual pheromone-mediated behaviour

“…By comparison, they have been less utilized for insects of conservation status, only emerging over the last 15 years as a new approach that applies research outputs to the conservation of insect biodiversity [ 23 ], including mitigating the impact of human intervention and climate change. Pheromones have been isolated and used successfully as a monitoring tool for Osmoderma eremita Scopoli (Coleoptera: Scarabaeidae) [ 15 ], Elater ferrugineus L. (Coleoptera: Elateridae) [ 12 , 17 ], Rosalia alpina L. (Coleoptera: Cerambycidae) [ 18 ] and Graellsia isabellae Graëlls (Leptidoptera: Saturniidae) [ 24 ], enabling European countries to detect and, in some cases, map the range of some of these species, thereby proving a valuable technique for monitoring elusive saproxylic beetles [ 13 , 15 ]. Since several members of the Scarabaeidae use volatile pheromones for sexual communication [ 25 ], and due to the urgent need for a non-destructive detection tool for the conservation of the noble chafer, G .…”

“…Chemical ecological tools such as pheromones can be used as a recording technique for scarab beetles, enabling European countries to detect and, in some cases, map the range of some of these species, thereby proving a valuable technique for monitoring elusive saproxylic beetles [ 12 – 18 ]. Since many species in the Scarabaeidae use pheromones for sexual communication, and as there is an urgent need for a non-destructive detection tool for the conservation of G .…”