Sesquiterpene Hydrocarbons: Kairomones with a releaser effect in the sexual communication of the white-spotted longicorn beetle, Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae)

Abstract

We conducted a series of experiments with the white-spotted longicorn beetle Anoplophora malasiaca (Thomson), and its host plant, Citrus unshiu, to examine the origin of the sesquiterpene hydrocarbons (SHCs; including b-elemene, b-caryophyllene, a-humulene, afarnesene, and several unidentified compounds) that are contained in the elytra of the beetles and act as an attractant. In the laboratory, mechanically wounded citrus branches, as well as those fed upon by A. malasiaca, attracted males more frequently than intact branches. Solid phase microextraction (SPME) and subsequent analyses by gas chromatography (GC) analyses detected measurable SHCs from the air around both mechanically wounded and beetle-infested branches, as well as trace amounts from intact branches. The SHCs were also detected for a certain time from beetles that had fed on the citrus branches, but the amounts decreased rapidly after they were removed from the host. This decrease generally corresponded with a reduction of attractiveness of the beetles in a behavioural assay. Isolated females acquired the SHCs after exposure to, but not upon contact with, other females that had fed on C. unshiu branches. We hypothesize that the citrus SHCs are adsorbed in, retained on, and released from the wax layer of the beetle elytra. Since these compounds are released from branches when beetles feed, they may indirectly signal the presence of beetles to others in the field. The high response rate to SHCs by males is likely representing mate searching behavior. The SHCs act as kairomones with a releaser effect in the communication system of A. malasiaca.

Chemical communication in mate location and recognition in the white-spotted longicorn beetle, Anoplophora malasiaca (Coleoptera: Cerambycidae)

“…Males as well as females attract both sexes. The attractant is in volatiles derived from host Citrus unshiu (Yasui et al, 2007b(Yasui et al, , 2008. The role of host plant volatiles in A. malasiaca is discussed in detail in the following sections.…”

“…However, the mating systems of Monochamus alternatus endai (Fauziah et al, 1987;Kim et al, 1992), Xylotrechus pyrrhoderus (Iwabuchi, 1982(Iwabuchi, , 1985(Iwabuchi, , 1988Sakai et al, 1984;Iwabuchi et al, 1985Iwabuchi et al, , 1986, Psacothea hilaris (Fukaya and Honda, 1992, 1996aFukaya et al, 1996Fukaya et al, , 1997, and especially A. malasiaca have been examined in various contexts, and a comprehensive representation has emerged for these species. Host plant chemicals play a role for searching mates at long and short distances in A. malasiaca (Yasui et al, 2007b(Yasui et al, , 2008. There are complex chemicals for mate recognition as contact pheromone in A. malasiaca (Fukaya et al, 1999(Fukaya et al, , 2000Akino et al, 2001;Fukaya, 2003;Yasui et al, 2003Yasui et al, , 2007a.…”

Behavioral responses of Steirastoma breve (Sulzer) (Coleoptera: Cerambycidae) to host plant Theobroma cacao L., brushwood piles, under field conditions

“…Freshly cut cocoa branches, such as those we evaluated, are still alive, and provide a large artificial source of damaged tissues emitting odors that could be attractants (kairomones) for S. breve adults. For example, sesquiterpene hydrocarbons, involved in the communication system of Anoplophora malasiaca at both long and short ranges, have been isolated from wounded host plants (Citrus unshiu) (Yasui et al, 2008;Yasui, 2009). Kairomones are often used by Cerambycidae as part of their communication system and have been used as bait to catch adult beetles regarded as agricultural pests, for example, Arhopalus tristis (Suckling et al, 2001), M. alternatus (Ikeda et al, 1980;Fan et al, 2007), Tetropium fuscum and T. castaneum (Sweeney et al, 2004(Sweeney et al, , 2006.…”

Uso de semioquímicos en el control de plagas. Estudios básicos y de aplicación

“…La técnica de SPME ha sido empleada principalmente para estudios en coleópteros (Said et al, 2003;Cai et al, 2007;Yasui et al, 2008;Arakaki et al, 2009), y recientemente para la identificación de sustancias emitidas por el tefrítido Anastrepha serpentina (Wiedemann) (Robacker et al, 2009). …”

“…SPME-gas chromatography (GC) was first applied in 1995 as an alternative method for the study of airborne insect pheromones (Malosse et al, 1995), and since then, SPME has been employed in sampling of insect volatiles, particularly in beetles (Said et al, 2003;Cai et al, 2007;Yasui et al, 2008;Arakaki et al, 2009). SPME has also been recently employed in the identification of chemicals emitted by Anastrepha serpentine (Robacker et al, 2009), but its use in medfly volatile collection has not yet been reported, as far as we know.…”