31 research outputs found
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A male-produced aggregation-sex pheromone of the beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) may be useful in managing this invasive species.
The longhorned beetle Arhopalus rusticus (Coleoptera: Cerambycidae, Spondylinae) is a common species in conifer forests of the Northern Hemisphere, but with global trade, it has invaded and become established in New Zealand, Australia, and South America. Arhopalus rusticus is a suspected vector of the phytopathogenic nematode, Bursaphelenchus xylophilus, the causative agent of pine wilt disease, which is a major threat to pine forests worldwide. Here, we report the identification of a volatile, male-produced aggregation-sex pheromone for this species. Headspace odours from males contained a major male-specific compound, identified as (2âS, 5E)-6,10-dimethyl-5,9-undecadien-2-ol (common name (S)-fuscumol), and a minor component (E)-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone). Both compounds are known pheromone components for species in the same subfamily. In field trials in its native range in Slovenia, (S)-fuscumol was significantly more attractive to beetles of both sexes, than racemic fuscumol and a blend of host plant volatiles commonly used as an attractant for this species. Fuscumol-baited traps also caught significant numbers of another spondylidine species, Spondylis buprestoides (L.), and a rare click beetle, Stenagostus rufus (De Geer). The pheromone can be exploited as a cost-effective and environmentally safe tool for detection and monitoring of this invasive species at ports of entry, and for monitoring the beetle's distribution and population trends in both endemic and invasive populations
Determination of the Relative and Absolute Configurations of the Female-produced Sex Pheromone of the Cerambycid Beetle Prionus californicus
We previously identified the basic structure of the female-produced sex attractant pheromone of the cerambycid beetle, Prionus californicus Motschulsky (Cerambycidae: Prioninae), as 3,5-dimethyldodecanoic acid. A synthesized mixture of the four stereoisomers of 3,5-dimethyldodecanoic acid was highly attractive to male beetles. Here, we describe stereoselective syntheses of three of the four possible stereoisomers, and the results of laboratory and field bioassays showing that male beetles are attracted specifically to (3R,5S)-3,5-dimethyldodecanoic acid, but not to its enantiomer, (3S,5R)-3,5-dimethyldodecanoic acid, indicating that the (3R,5S)-enantiomer is the active pheromone component. The diastereomeric (3R,5R)- and (3S,5S)-enantiomers were excluded from consideration because their gas chromatographic retention times were different from that of the insect-produced compound. The mixture of the four stereoisomers of 3,5-dimethyldodecanoic acid was as attractive to male P. californicus as the (3R,5S)-enantiomer, indicating that none of the other three stereoisomers inhibited responses to the active enantiomer. Beetles responded to as little as 10Â ng and 10Â ÎŒg of synthetic 3,5-dimethyldodecanoic acid in laboratory and field studies, respectively. Field studies indicated that capture rate did not increase with dosages of 3,5-dimethyldodecanoic acid greater than 100Â ÎŒg. In field bioassays, males of a congeneric species, P. lecontei Lameere, were captured in southern California but not in Idaho
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(R)-Desmolactone Is a Sex Pheromone or Sex Attractant for the Endangered Valley Elderberry Longhorn Beetle Desmocerus californicus dimorphus and Several Congeners (Cerambycidae: Lepturinae)
We report here that (4R,9Z)-hexadec-9-en-4-olide [(R)-desmolactone] is a sex attractant or sex pheromone for multiple species and subspecies in the cerambycid genus Desmocerus. This compound was previously identified as a female-produced sex attractant pheromone of Desmocerus californicus californicus. Headspace volatiles from female Desmocerus aureipennis aureipennis contained (R)-desmolactone, and the antennae of adult males of two species responded strongly to synthetic (R)-desmolactone in coupled gas chromatography-electroantennogram analyses. In field bioassays in California, Oregon, and British Columbia, traps baited with synthetic (R)-desmolactone captured males of several Desmocerus species and subspecies. Only male beetles were captured, indicating that this compound acts as a sex-specific attractant, rather than as a signal for aggregation. In targeted field bioassays, males of the US federally threatened subspecies Desmocerus californicus dimorphus responded to the synthetic attractant in a dose dependent manner. Our results represent the first example of a ââgenericââ sex pheromone used by multiple species in the subfamily Lepturinae, and demonstrate that pheromone-baited traps may be a sensitive and efficient method of monitoring the threatened species Desmocerus californicus dimorphus, commonly known as the valley elderberry longhorn beetle
Identification of the Sex Pheromone of a Protected Species, the Spanish Moon Moth Graellsia isabellae
Sex attractant pheromones are highly sensitive and selective tools for detecting and monitoring populations of insects, yet there has been only one reported case of pheromones being used to monitor protected species. Here, we report the identification and synthesis of the sex pheromone of a protected European moth species, Graellsia isabellae (Lepidoptera: Saturniidae), as the single component, (4E,6E,11Z)-hexadecatrienal. In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species
âNothing about us without usâ : disabled people determining their human rights through the UNCRPD
The human rights and fundamental freedoms of disabled persons are set out in the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD). This paper firstly focuses on the importance of the involvement of disabled people at all levels of decision-making. The second part of the paper identifies those aspects of the UNCRPD that reflect the direct involvement of disabled people. Finally, it considers how human rights bodies can best build on this specific aspect of the UNCRPD in order to realize the potential of the Convention as a determining factor in affirming disabled people rights in an effective and meaningful manner.peer-reviewe
Identification and Synthesis of a Female-Produced Sex Pheromone for the Cerambycid Beetle Prionus Californicus
Determination of the Relative and Absolute Configurations of the Female-produced Sex Pheromone of the Cerambycid Beetle Prionus californicus
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Deceptive signals and behaviors of a cleptoparasitic beetle show local adaptation to different host bee species
Chemosensory signals play a key role in species recognition and mate location in both invertebrate and vertebrate species. Closely related species often produce similar but distinct signals by varying the ratios or components in pheromone blends to avoid interference in their communication channels and minimize cross-attraction among congeners. However, exploitation of reproductive signals by predators and parasites also may provide strong selective pressure on signal phenotypes. For example, bolas spiders mimic the pheromones of several moth species to attract their prey, and parasitic blister beetle larvae, known as triungulins, cooperatively produce an olfactory signal that mimics the sex pheromone of their female host bees to attract male bees, as the first step in being transported by their hosts to their nests. In both cases, there is strong selection pressure on the host to discriminate real mates from aggressive mimics and, conversely, on the predator, parasite, or parasitoid to track and locally adapt to the evolving signals of its hosts. Here we show local adaptation of a beetle, Meloe franciscanus (Coleoptera: Meloidae), to the pheromone chemistry and mate location behavior of its hosts, two species of solitary bees in the genus Habropoda We report that Mfranciscanus' deceptive signal is locally host-adapted in its chemical composition and ratio of components, with host bees from each allopatric population preferring the deceptive signals of their sympatric parasite population. Furthermore, in different locales, the triungulin aggregations have adapted their perching height to the height at which local male bees typically patrol for females
Isolation and determination of absolute configurations of insect-produced methyl-branched hydrocarbons
Although the effects of stereochemistry have been studied extensively for volatile insect pheromones, little is known about the effects of chirality in the nonvolatile methyl-branched hydrocarbons (MBCHs) used by many insects as contact pheromones. MBCHs generally contain one or more chiral centers and so two or more stereoisomeric forms are possible for each structure. However, it is not known whether insects biosynthesize these molecules in high stereoisomeric purity, nor is it known whether insects can distinguish the different stereoisomeric forms of MBCHs. This knowledge gap is due in part to the lack of methods for isolating individual MBCHs from the complex cuticular hydrocarbon (CHC) blends of insects, as well as the difficulty in determining the absolute configurations of the isolated MBCHs. To address these deficiencies, we report a straightforward method for the isolation of individual cuticular hydrocarbons from the complex CHC blend. The method was used to isolate 36 pure MBCHs from 20 species in nine insect orders. The absolute stereochemistries of the purified MBCHs then were determined by digital polarimetry. The absolute configurations of all of the isolated MBCHs were determined to be (R) by comparison with a library of synthesized, enantiomerically pure standards, suggesting that the biosynthetic pathways used to construct MBCHs are highly conserved within the Insecta. The development of a straightforward method for isolation of specific CHCs will enable determination of their functional roles by providing pure compounds for bioassays