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

Abstract

We studied the pheromone chemistry of the cerambycids Anaglyptus mysticus and Xylotrechus antilope ssp. antilope with the goal of identifying attractants that could be used as tools for pheromone-based monitoring of these two species, which are rare and red-listed in parts of northern Europe. Beetles were reared from naturally colonized branches of hazel (Corylus avellana) or oak (Quercus robur), respectively, and used for headspace sampling. The extracts of volatiles were analyzed by gas chromatography-mass spectrometry. Males of A. mysticus consistently produced large quantities of (R)-3-hydroxy-2-hexanone and 2-nonanone, minor amounts of 2,3-hexanedione, and trace amounts of six other compounds. The average proportion of 2-nonanone to (R)-3-hydroxy-2-hexanone was 70:100. Males of X. antilope produced large quantities of (S)-2-hydroxy-3-octanone, and minor quantities of 2,3-octanedione. None of these compounds were present in the corresponding extracts of females from either species. The attractiveness of the dominant compounds produced by each species was determined in field bioassays. Lures with racemic 3-hydroxy-2-hexanone and 2-nonanone as single compounds were not attractive to A. mysticus. However, the compounds acted synergistically in blends of 100:100 and 160:100 of 2-nonanone to the hydroxyketone's (R)-enantiomer, but not in a 40:100 blend. Similarly (S)-2-hydroxy-3-octanone and its racemate attracted significantly more X. antilope than controls. Males and females of both species were captured in approximately equal numbers. The aggregation-sex pheromones of A. mysticus and X.antilope have high potential to serve as sensitive and efficient tools for detection and monitoring of local populations, and in studies of the species' ecology and conservation requirements.

Identification of Pheromone Components of Plagionotus detritus (Coleoptera: Cerambycidae), and Attraction of Conspecifics, Competitors, and Natural Enemies to the Pheromone Blend

“…In the present study, X. antilope was attracted by 2-C8 as a single component, confirming earlier results [40], where the S-enantiomer of 2-C8 was identified as the major and likely only component of its pheromone. Males of several longhorn beetle species, particularly in the genus Xylotrechus, produce 2-C8, which is also produced by male Plagionotus christophi [41,42].…”

“…Xylotrechus antilope is considered rare and is red-listed by the International Union for Conservation of Nature (IUCN) among endangered species. Its populations are severely fragmented due to logging and wood harvesting in parts of northern Europe [39,40].…”

Exploiting trap color to improve surveys of longhorn beetles

“…The difference in color preference might be linked either to the colors of the most commonly visited flowers or to differences in the (visual guided) mate-finding behavior. X. stebbingi and X. colonus, for example, are mainly crepuscular or nocturnal species (Rassati et al 2020), whereas X. antilope is mainly diurnal, with maximal activity in the late morning to early afternoon (Molander et al 2019). This difference is also reflected in their body coloration: X. antilope is black with yellow stripes and likely mimic vespid wasps (Mitchell et al 2017), X. stebbingi and X. colonus are reddish-grayish, which likely allow them to camouflage when moving on tree bark.…”

Latest Developments in Insect Sex Pheromone Research and Its Application in Agricultural Pest Management

“…Sex pheromones are mainly produced by females and used as attractant compounds to show the presence of potential mating partners and their reproductive status [ 8 , 11 ]. Sex pheromones comprise sex attractant pheromones, which induce upwind oriented movements to the conspecific individual, and courtship pheromones, which elicit a variety of close-range responses in the insect partner [ 12 , 13 ]. Since the first pheromone discovery, the rapid progress of methodologies developed to identify new pheromones, mainly GC, GC-MS, NMR, electrophysiological techniques [electroantennography (EAG), gas chromatography coupled to electroantennography (GC-EAD), single sensillum recordings (SSR), and coupled GC-SSR], have allowed the identification of thousands of compounds as insect sex pheromones [ 14 ] ( Table 2 contains new sex pheromones and sex pheromone components recently identified from insect pests in the period 2010–2020 and the corresponding references [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]).…”